@article{2-s2.0-85174449310,

title = {Size-dependent and sex-specific negative effects of micro- and nano-sized polystyrene particles in the terrestrial invertebrate model Drosophila melanogaster},

author = { A.Z. Urbisz and K. Małota and Ł. Chajec and M.K. Sawadro},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85174449310&doi=10.1016%2fj.micron.2023.103560&partnerID=40&md5=77068cdc7cddfb39fc67f8ce276d7ee0},

doi = {10.1016/j.micron.2023.103560},

issn = {09684328},

year  = {2024},

date = {2024-01-01},

journal = {Micron},

volume = {176},

publisher = {Elsevier Ltd},

abstract = {Microplastic pollution is believed to be one of the most widespread and long-lasting changes on a global scale. Our understanding that microplastics significantly impact terrestrial systems and are a global change stressor continues to grow. In the present study, we investigated the negative effect of long-term (28 days of exposure in food) polystyrene particles of micro (1.0–1.9 µm; 0.4–0.6 µm) and nano (0.04–0.06 µm) scale, in low doses, on the fruit fly – representing a common, globally distributed terrestrial invertebrate, and a model species in many fields. Our observations involved such parameters as ingestion and transfer of particles, survival, reproduction, changes in ultrastructure and tissue and cell responses in midgut epithelium (the place of direct contact with plastic), ovary, and testis in adults, and transgenerational effects in larvae. These observations may indicate possible toxic effects of the tested substances, even in low doses, that can be expected in other taxa, in terrestrial ecosystems. We observed a negative impact of polystyrene particles on the fruit fly survival, midgut, ovary, and testis, involving ultrastructural alterations, such as autophagy and/or ultimately necrosis in the midgut, triggering oxidative stress and activating processes of antioxidative protection. Despite the changes, midgut function and reproduction were not altered – spermatogenesis and oogenesis proceeded normally. The effect was size-dependent – the smaller the polystyrene particles were, the more substantial was the impact they caused. Ultrastructural changes and studied parameters, i.e., generation of ROS (overproduction of which generates oxidative stress), total glutathione concentration (involved in defense against ROS; acting in distinct pathways), and total antioxidant concentration (the oxidative defense system) showed the highest levels after exposure to the smallest nanoparticles, and vice versa. The effect was also sex-dependent, with male flies being more sensitive. Negative effects in males were more substantial and more prominent, even after contact with larger particles, compared to females. The smaller particles (0.4–0.6 µm; 0.04–0.06 µm) were transferred to the ovary and accumulated in the oocytes. In this case, a transgenerational negative effect was detected in larvae. It was characterized by size-dependent alterations, with smaller particles triggering higher levels of ROS and cellular oxidative response. Only the largest particles (1.0–1.9 µm) did not pass into the gonad and did not alter the larvae. These observations together demonstrated that polystyrene particles of micro- and nanoscale, even in a low dose, can induce numerous negative effects on terrestrial invertebrates. © 2023 The Authors},

note = {1},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85172034597,

title = {Ovary organization and ultrastructure in six species of Amynthas and Metaphire earthworms (Annelida, Crassiclitellata, Megascolecidae)},

author = { P. Świątek and R.S. Thounaojam and T.B. Singh and S.W. James and Ł. Gajda and K. Małota and D. Raś and A.Z. Urbisz},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85172034597&doi=10.1016%2fj.zool.2023.126109&partnerID=40&md5=bec781203453b14de5a944a8329023bc},

doi = {10.1016/j.zool.2023.126109},

issn = {09442006},

year  = {2023},

date = {2023-01-01},

journal = {Zoology},

volume = {160},

publisher = {Elsevier GmbH},

abstract = {Ovaries in earthworms belonging to the family Megascolecidae are paired structures attached to the septum in the anterior part of the XIII segment. They are fan to rosette shaped with numerous rows of growing oocytes, known as egg strings, radiating from the ovary center towards the segmental cavity. The histological and ultrastructural ovary organization in megascolecids and the course of oogenesis remain unknown. The paper presents the results of light and electron microscopy analyses of ovaries in six megascolecid species, three from the genus Amynthas and three from Metaphire. Both parthenogenetic and sexually reproducing species were included in the study. The organization and ultrastructure of ovaries in all studied species are broadly similar. Considering the histological organization of ovaries, they could be divided into two zones. Zone I (proximal; close to the connection with the septum) is tightly packed with germline and somatic cells. Germ cells are interconnected via intercellular bridges and thin strands of the central cytoplasm (known as cytophore) and form syncytial cysts. Cysts unite oogonia, early meiotic cells (till diplotene), and clustering cells develop synchronously. During diplotene, interconnected cells lose developmental synchrony; most probably, one cell per cyst grows faster than others, detaches from the cysts, and becomes an oocyte. The remaining cells grow slightly and are still interconnected via the thin and reticular cytophore; these cells are considered nurse cells. Zone II has a form of egg strings where growing oocytes are isolated one from another by thin somatic cells and form short cords. We present the ultrastructural details of germline and somatic cells. We propose the term “Amynthas” type of ovaries for this ovary organization. We suppose that such ovaries are characteristic of other megascolecids and related families. © 2023 The Authors},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85151449439,

title = {Uncovering nanotoxicity of a water-soluble and red-fluorescent [70]fullerene nanomaterial},

author = { D. Dreszer and G.M. Szewczyk and M. Szubka and A. Maroń and A.Z. Urbisz and K. Małota and J. Sznajder and M.M. Rost-Roszkowska and R. Musioł and M. Serda},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85151449439&doi=10.1016%2fj.scitotenv.2023.163052&partnerID=40&md5=d39a18e5d9df9484ec32cd0bbc2dafe3},

doi = {10.1016/j.scitotenv.2023.163052},

issn = {00489697},

year  = {2023},

date = {2023-01-01},

journal = {Science of the Total Environment},

volume = {879},

publisher = {Elsevier B.V.},

abstract = {Engineered fullerene materials have attracted the attention of researchers in the biomedical sciences, especially when their synthetic methodology is developed to endow them with significant levels of water-solubility and bioavailability. In this study, we synthesized and characterized a water-soluble and red-fluorescent [70]fullerene nanomaterial, which fluoresced at 693 nm with a quantum yield of 0.065 and a large Stokes shift (around 300 nm). The fullerene nanomaterial generated mainly singlet oxygen after illumination with blue LED light, while superoxide anion radical production was minimal. The transmission electron microscopy as well as fluorescent studies of Drosophila melanogaster revealed that prepared [70]fullerene nanoparticles had better bioavailability than pristine [70]fullerene nanoparticles. The designed nanomaterials were observed in the apical, perinuclear, and basal regions of digestive cells, as well as the basal lamina of the digestive system's epithelium, with no damage to cell organelles and no activation of degenerative processes and cell death. Our findings provide a new perspective for understanding the in vivo behavior of fullerene nanomaterials and their future application in bioimaging and light-activated nanotherapeutics. © 2023 Elsevier B.V.},

note = {2},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85149392370,

title = {Ovary micromorphology in hormogastrid earthworms with a particular emphasis on the organization of the germline cysts},

author = { P. Świątek and M. Novo and D.F. Marchán and Ł. Gajda and K. Małota and A.Z. Urbisz},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85149392370&doi=10.1016%2fj.zool.2023.126081&partnerID=40&md5=af7f147977e3ccab60235da47897acb6},

doi = {10.1016/j.zool.2023.126081},

issn = {09442006},

year  = {2023},

date = {2023-01-01},

journal = {Zoology},

volume = {158},

publisher = {Elsevier GmbH},

abstract = {There is a gap in our knowledge of microorganization and the functioning of ovaries in earthworms (Crassiclitellata) and allied taxa. Recent analyses of ovaries in microdriles and leech-like taxa revealed that they are composed of syncytial germline cysts accompanied by somatic cells. Although the pattern of cyst organization is conserved across Clitellata – each cell is connected via one intercellular bridge (ring canal) to the central and anuclear cytoplasmic mass termed the cytophore – this system shows high evolutionary plasticity. In Crassiclitellata, only the gross morphology of ovaries and their segmental localization is well known, whereas ultrastructural data are limited to lumbricids like Dendrobaena veneta. Here we present the first report about ovarian histology and ultrastructure in Hormogastridae, a small family of earthworms inhabiting the western parts of the Mediterranean sea basin. We analyzed three species from three different genera and showed that the pattern of ovary organization is the same within this taxon. Ovaries are cone-like, with a broad part connected to the septum and a narrow distal end forming an egg string. Ovaries are composed of numerous cysts uniting a small number of cells, eight in Carpetania matritensis. There is a gradient of cysts development along the long ovary axis, and three zones can be distinguished. In zone I, cysts develop in complete synchrony and unite oogonia and early meiotic cells (till diplotene). Then (zone II), the synchrony is lost, and one cell (prospective oocyte) grows faster than the rest (prospective nurse cells). In zone III, oocytes pass the growth phase and gather nutrients; at this time, their contact with the cytophore is lost. Nurse cells grow slightly, eventually die via apoptosis, and are removed by coelomocytes. The most characteristic feature of hormogastrid germ cysts is the inconspicuous cytophore in the form of thread-like thin cytoplasmic strands (reticular cytophore). We found that the ovary organization in studied hormogastrids is very similar to that described for D. veneta and propose the term “Dendrobaena” type of ovaries. We expect the same microorganization of ovaries will be found in other hormogastrids and lumbricids. © 2023 Elsevier GmbH},

note = {1},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85127523380,

title = {A microscopy investigation of the complex problem of infertility of insect hybrids. Studies on the reproductive systems, eggshells, and karyotypes of the representatives of the genus Platymeris (Heteroptera, Reduviidae) and their hybrids},

author = { A. Bugaj-Nawrocka and Ł. Chajec and A.Z. Urbisz and D. Chłond},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85127523380&doi=10.1016%2fj.micron.2022.103248&partnerID=40&md5=00bc8948a83beadd752635d0af3d7abf},

doi = {10.1016/j.micron.2022.103248},

issn = {09684328},

year  = {2022},

date = {2022-01-01},

journal = {Micron},

volume = {158},

publisher = {Elsevier Ltd},

abstract = {Hybridisation is still a widely studied phenomenon that allows us to look at some processes differently. However, obtaining fertile hybrids, which we might consider in the long term as precursors of a new species, is still a field that requires research. Much of the research done so far indicates that hybrids are sterile – either sex or both. It is influenced by various mechanisms, both prezygotic and postzygotic reproductive isolation. Thanks to the use of light and transmission electron microscopy, our research has made it possible to understand, at least partially, the causes of infertility in male hybrids resulting from the crossing of two Afrotropical species of the genus Platymeris Laporte, 1833. The analysis of microscopic images showed that one of the possible causes of the infertility of hybrids might be spermatogenesis, during which sperm cells were not formed. In turn, the use of scanning electron microscopy revealed potential abnormalities in the structure of the hybrid eggshell. Moreover, karyotyping analyses suggest possible causes of infertility at the genetic level. © 2022 Elsevier Ltd},

note = {2},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85132453288,

title = {All for one: changes in mitochondrial morphology and activity during syncytial oogenesis},

author = { A.Z. Urbisz and Ł. Chajec and K. Małota and S. Student and M.K. Sawadro and M.A. Śliwińska and P. Świątek},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85132453288&doi=10.1093%2fbiolre%2fioac035&partnerID=40&md5=d4f195796e8b35b1b64af31d1ab12b47},

doi = {10.1093/biolre/ioac035},

issn = {00063363},

year  = {2022},

date = {2022-01-01},

journal = {Biology of Reproduction},

volume = {106},

number = {6},

pages = {1232-1253},

publisher = {Oxford University Press},

abstract = {The syncytial groups of germ cells (germ-line cysts) forming in ovaries of clitellate annelids are an attractive model to study mitochondrial stage-specific changes. Using transmission electron microscopy, serial block-face scanning electron microscopy, and fluorescent microscopy, we analyzed the mitochondria distribution and morphology and the state of membrane potential in female cysts in Enchytraeus albidus. We visualized in 3D at the ultrastructural level mitochondria in cysts at successive stages: 2-celled, 4-celled, 16-celled cysts, and cyst in advanced oogenesis. We found that mitochondria form extensive aggregates-they are fused and connected into large and branched mitochondrial networks. The most extensive networks are formed with up to 10 000 fused mitochondria, whereas individual organelles represent up to 2% of the total mitochondrial volume. We classify such a morphology of mitochondria as a dynamic hyperfusion state and suggest that this can maintain their high activity and intensify the process of cellular respiration within the syncytial cysts. We found some individual mitochondria undergoing degradation, which implies that damaged mitochondria are removed from networks for their final elimination. As growing oocytes were shown to possess less active mitochondria than the nurse cells, the high activity of mitochondria in the nurse cells and their dynamic hyperfusion state are attributed to serve the needs of the growing oocyte. In addition, we measured by calorimetry the total antioxidant capacity of germ-line cysts in comparison with somatic tissue, and it suggests that antioxidative defense systems, together with mitochondrial networks, can effectively protect germ-line mitochondria from damage. © 2022 The Author(s). Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved.},

note = {2},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85124908727,

title = {Ovary micromorphology and oogenesis in a rhyacodriline oligochaete (Clitellata: Naididae, Rhyacodrilinae)},

author = { P. Świątek and P. Rodriguez and K. Małota and A.Z. Urbisz},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85124908727&doi=10.1002%2fjmor.21461&partnerID=40&md5=ac6de8f8304d7e49939284f6e9883964},

doi = {10.1002/jmor.21461},

issn = {03622525},

year  = {2022},

date = {2022-01-01},

journal = {Journal of Morphology},

volume = {283},

number = {5},

pages = {605-617},

publisher = {John Wiley and Sons Inc},

abstract = {The main goal of the article is to describe the ovary organization and oogenesis in Peristodrilus montanus, an aquatic oligochaete of the subfamily Rhyacodrilinae. The presented analysis will not only enrich the knowledge about how eggs are formed but, because of the suggested conservatism of ovary organization in clitellate annelids, can contribute to disentangling the complex phylogenetic relationships of the rhyacodrilines within Naididae. The paired, conically shaped ovaries are located in segment XI. They are composed of a dozen or so syncytial germ-line cysts, which are associated with somatic cells. Each germ cell in a cyst has one intercellular bridge that joins it to a central and anuclear cytoplasmic mass, the cytophore. This pattern of cyst organization is typical for all clitellates that have been studied to date. Initially, the germ cells in a cyst undergo a synchronous development, however, there is no synchrony between cysts, and therefore there is a developmental gradient (oogonia; pre-diplotene germ cells; germ cells in diplotene) of oogenesis along the long ovary axis. The cysts are composed of a maximum of 32 cells. Cysts with cells in diplotene detach from the ovaries and the extraovarian phase of oogenesis begins. The developmental synchrony is lost, one cell (an oocyte) per cyst starts to gather cell components and yolk and grows considerably. The remaining cells grow to some extent and function as nurse cells. Like in other microdriles, P. montanus oocytes are rich in yolk; other features of oogenesis are also similar to those that are known from other microdrile taxa. The system of ovary organization found in the studied species is broadly similar to the corresponding features known from Naidinae and Phreodrilidae and, to some extent, in Enchytraeidae. However, this system is different from the one that is known in Tubificinae, Limnodriloidinae and Branchiurinae. © 2022 Wiley Periodicals LLC.},

note = {2},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85124110458,

title = {Germ-line cysts in animal gametogenesis - genesis, organization and functioning [Zespoły komórek płciowych w gametogenezie zwierząt - geneza, organizacja i funkcjonowanie]},

author = { P. Świątek and A.Z. Urbisz},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85124110458&doi=10.18388%2fpb.2021_408&partnerID=40&md5=1ebd43992220c12cdaf623789581288a},

doi = {10.18388/pb.2021_408},

issn = {00325422},

year  = {2021},

date = {2021-01-01},

journal = {Postepy biochemii},

volume = {67},

number = {4},

pages = {309-322},

publisher = {NLM (Medline)},

abstract = {During early gametogenesis the incomplete mitotic divisions occur. The cytokinesis is blocked and the sister cells do not fully separate. Instead, they stay connected via modified contractile rings known as stable intercellular bridges or ring canals. Intercellular bridges are broad cytoplasmic strands (from 0;2μm to 20μm in diameter), which allow to exchange the gene products and organelles between interconnected cells. Such syncytial structures are termed germ-line cysts. As a rule, cysts are formed during spermatogenesis and they interconnect germ cells till sperm formation. In the female germ-line (oogenesis) cysts may not form at all, may be formed for a short period of time (till early meiosis) or may function till late oogenesis. Despite of universal mechanism of cysts formation (incomplete cytokinesis and bridge formation) there are substantial differences in cysts organization and functioning between taxa. The present paper gives the basic knowledge about formation and functioning of male and female germ-line cysts.W trakcie wczesnej gametogenezy zwierząt pojawiają się nietypowe podziały mitotyczne komórek płciowych, które nie kończą się pełną cytokinezą. W konsekwencji potomne komórki nie są kompletnie rozdzielone ale pozostają przez pewien czas połączone zmodyfikowanymi pierścieniami zaciskowymi zwanymi stabilnymi mostkami międzykomórkowymi. Mostki te to na tyle szerokie pasma cytoplazmy (od 0;2 μm do 20 μm), że możliwa jest wymiana zarówno produktów genowych jak i organelli pomiędzy połączonymi komórkami. Takie syncytialne twory nazywamy zespołami (cystami) komórek płciowych. Zespoły występują powszechnie w trakcie spermatogenezy zwierząt łącząc z sobą męskie komórki płciowe aż do ich przekształcenia w plemniki. W linii żeńskiej (oogeneza) zespoły mogą się w ogóle nie formować, powstają na bardzo krótki czas (do początku mejozy) lub na dłużej (do zaawansowanej oogenezy). Pomimo uniwersalnego mechanizmu powstawania zespołów (niepełna cytokineza) obserwujemy dużą różnorodność w ich organizacji przestrzennej i funkcjonowaniu. Niniejszy artykuł przedstawia podstawowe fakty związane z powstawaniem i funkcjonowaniem zespołów komórek płciowych w linii męskiej i żeńskiej.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85092754890,

title = {Microorganization of ovaries and oogenesis of Haplotaxis sp. (Clitellata: Haplotaxidae)},

author = { A.Z. Urbisz and P. Martin and M. Lagnika and Ł. Chajec and P. Świątek},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85092754890&doi=10.1002%2fjmor.21285&partnerID=40&md5=34f7ba41b3dadeb3e9ec5b76cc8b5f8b},

doi = {10.1002/jmor.21285},

issn = {03622525},

year  = {2021},

date = {2021-01-01},

journal = {Journal of Morphology},

volume = {282},

number = {1},

pages = {98-114},

publisher = {John Wiley and Sons Inc},

abstract = {Ovaries of Haplotaxis sp. were studied in active and nonactive states, that is, in a sexually mature specimen and in specimens outside of the reproductive period. Two pairs of ovaries were found in segments XI and XII. Especially in the nonactive state, they were in close contact with copulatory glands. Each ovary was composed of germ cells interconnected with syncytial cysts, which were enveloped by a layer of somatic cells. Within cysts each germ cell had one ring canal connecting it to the common anuclear cytoplasmic mass called a cytophore. During oogenesis clustering germ cells differentiated into nurse cells and oocytes; thus, the oogenesis was recognized as meroistic. Vitellogenic oocytes were detached from the ovaries and continued yolk absorption within the body cavity. Because recent studies have shown the variety of ovaries and germ line cyst organization in clitellates and suggest their evolutionary conservatism at the family or subfamily level, the data presented here can be valid in understanding the phylogenetic relationships among Clitellata. In this context, ovaries found in Haplotaxis sp. resembled those of the “Tubifex” type. “Tubifex” ovaries are characteristic for numerous microdrile taxa (tubificines; limnodriloidines; propappids; lumbriculids; and leech-like branchiobdellids) and can be regarded as the primary character for these Clitellata in which germ-line cysts are formed during early oogenesis. As the family Haplotaxidae is currently considered to be paraphyletic and the species studied here belongs to Haplotaxidae sensu stricto, our results support the close relationship of Haplotaxidae sensu stricto to the clade consisting of Lumbriculidae, Branchiobdellida, and Hirudinida, in which lumbriculids are sister to the latter two. © 2020 Wiley Periodicals LLC.},

note = {3},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85092408054,

title = {An ultrastructural study of the ovary cord organization and oogenesis in the amphibian leech Batracobdella algira (Annelida, Clitellata, Hirudinida)},

author = { R. Ben Ahmed and A.Z. Urbisz and P. Świątek},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85092408054&doi=10.1007%2fs00709-020-01560-7&partnerID=40&md5=b91155d5f2d90b84c2b2383a2d3a2925},

doi = {10.1007/s00709-020-01560-7},

issn = {0033183X},

year  = {2021},

date = {2021-01-01},

journal = {Protoplasma},

volume = {258},

number = {1},

pages = {191-207},

publisher = {Springer},

abstract = {This study reveals the ovary micromorphology and the course of oogenesis in the leech Batracobdella algira (Glossiphoniidae). Using light, fluorescence, and electron microscopies, the paired ovaries were analyzed. At the beginning of the breeding season, the ovaries were small, but as oogenesis progressed, they increased in size significantly, broadened, and elongated. A single convoluted ovary cord was located inside each ovary. The ovary cord was composed of numerous germ cells gathered into syncytial groups, which are called germ-line cysts. During oogenesis, the clustering germ cells differentiated into two functional categories, i.e., nurse cells and oocytes, and therefore, this oogenesis was recognized as being meroistic. As a rule, each clustering germ cell had one connection in the form of a broad cytoplasmic channel (intercellular bridge) that connected it to the cytophore. There was a synchrony in the development of the clustering germ cells in the whole ovary cord. In the immature leeches, the ovary cords contained undifferentiated germ cells exclusively, from which, previtellogenic oocytes and nurse cells differentiated as the breeding season progressed. Only the oocytes grew considerably, gathered nutritive material, and protruded at the ovary cord surface. The vitellogenic oocytes subsequently detached from the cord and filled tightly the ovary sac, while the nurse cells and the cytophore degenerated. Ripe eggs were finally deposited into the cocoons. A comparison of the ovary structure and oogenesis revealed that almost all of the features that are described in the studied species were similar to those that are known from other representatives of Glossiphoniidae, which indicates their evolutionary conservatism within this family. © 2020, Springer-Verlag GmbH Austria, part of Springer Nature.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85090244168,

title = {Ovary cord micromorphology in the blood-sucking haemadipsid leech Haemadipsa japonica (Hirudinida: Arhynchobdellida: Hirudiniformes)},

author = { A.Z. Urbisz and T. Nakano and P. Świątek},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85090244168&doi=10.1016%2fj.micron.2020.102929&partnerID=40&md5=0805deeb401b5e847149c6b5a566c1e8},

doi = {10.1016/j.micron.2020.102929},

issn = {09684328},

year  = {2020},

date = {2020-01-01},

journal = {Micron},

volume = {138},

publisher = {Elsevier Ltd},

abstract = {This is the first report that describes histological and ultrastructural details of ovary organization in haemadipsid leeches. In Haemadipsa japonica, the female reproductive system is organized similar to that of other haemadipsids. Each of the paired and oval ovaries of H. japonica is comprised of the ovary wall (ovisac), which encloses two elongated, thread-like ovarian units termed ovary cords. Ovary cords are comprised of germ-line cells and associated somatic cells. Each cord is polarized and contains germ-line cells in the consecutive developmental stages that are sequentially located along the long cord axis. There were three zones in each cord: the club-shaped apical part, the thread-like middle part, and the basal-most end, which contains degenerating germ cells. Outside of the reproductive period, the middle part of the cord in leeches is smooth, and no growing oocytes are visible; alternatively, in mature specimens, several growing oocytes protrude from the cord, and several huge vitellogenic oocytes that are completely detached from the cord occur within the ovisac. Ovary cord organization and functioning in H. japonica are very similar to the ‘Hirudo’ type cords that were found in several hirudiniform leeches. This conclusion supports the view that all hirudiniform leeches have conservative ovary cord organization and a similar pattern of oogenesis. Germ-line cyst composition, architecture, and functioning were also found to be evolutionarily conservative characteristics when compared with all previously examined Clitellata. In the germ-line cysts found in H. japonica each cell is connected to the central and anuclear cytoplasmic mass (cytophore) via one intercellular bridge, and, as oogenesis progresses, the fate of interconnected cell diversifies: some of them (oocytes) grow and complete oogenesis, but the majority become nurse cells and finally degenerate. Thus, oogenesis in H. japonica, similar to other clitellates, can be considered meroistic. © 2020 Elsevier Ltd},

note = {4},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85078176887,

title = {Morphology of Mitochondria in Syncytial Annelid Female Germ-Line Cyst Visualized by Serial Block-Face SEM},

author = { A.Z. Urbisz and S. Student and M.A. Śliwińska and K. Małota},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85078176887&doi=10.1155%2f2020%2f7483467&partnerID=40&md5=786d379712fb68bcd79a814829a73569},

doi = {10.1155/2020/7483467},

issn = {16878876},

year  = {2020},

date = {2020-01-01},

journal = {International Journal of Cell Biology},

volume = {2020},

publisher = {Hindawi Limited},

abstract = {Mitochondria change their morphology and distribution depending on the metabolism and functional state of a cell. Here, we analyzed the mitochondria and selected structures in female germ-line cysts in a representative of clitellate annelids - the white worm Enchytraeus albidus in which each germ cell has one cytoplasmic bridge that connects it to a common cytoplasmic mass. Using serial block-face scanning electron microscopy (SBEM), we prepared three-dimensional ultrastructural reconstructions of the entire selected compartments of a cyst at the advanced stage of oogenesis, i.e. the nurse cell, cytophore, and cytoplasmic bridges of all 16 cells (15 nurse cells and oocyte). We revealed extensive mitochondrial networks in the nurse cells, cytophore and mitochondria that pass through the cytoplasmic bridges, which indicates that a mitochondrial network can extend throughout the entire cyst. The dynamic hyperfusion state was suggested for such mitochondrial aggregations. We measured the mitochondria distribution and revealed their polarized distribution in the nurse cells and more abundant accumulation within the cytophore compared to the nurse cell. A close association of mitochondrial networks with dispersed nuage material, which seems to be the structural equivalent of a Balbiani body, not described in clitellate annelids so far, was also revealed. © 2020 Anna Z. Urbisz et al.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85065662274,

title = {Characterisation of white and yellow eye colour mutant strains of house cricket, Acheta domesticus},

author = { J. Francikowski and M. Krzyżowski and B. Kochańska and M. Potrzebska and B. Baran and Ł. Chajec and A.Z. Urbisz and K. Małota and B. Łozowski and M. Kloc and J. Kubiak},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85065662274&doi=10.1371%2fJOURNAL.PONE.0216281&partnerID=40&md5=f7c1822cf373b0ac1bceaf810a30d257},

doi = {10.1371/JOURNAL.PONE.0216281},

issn = {19326203},

year  = {2019},

date = {2019-01-01},

journal = {PLoS ONE},

volume = {14},

number = {5},

publisher = {Public Library of Science},

abstract = {Two eye-colour mutant strains, white (W) and yellow (Y) of house cricket Acheta domesticus were established in our laboratory. We phenotyped and genotyped the mutants, performed genetic crossings and studied the eye structure and pigment composition using light and electron microscopy and biochemical analysis. We show that W and Y phenotypes are controlled by a single autosomal recessive allele, as both traits are metabolically independent. The analysis of the mutants'eye structure showed a reduced number of dark pigment granules while simultaneously, and an increased amount of light vacuoles in white eye mutants was observed. Significant differences in eye pigment composition between strains were also found. The Y mutant had a lower number of ommochromes, while the W mutant had a lower number of ommochromes and pteridines. This indicates that mutated genes are involved in two different, independent metabolic pathways regulating tryptophan metabolism enzymes, pigment transporter granules or pigment granule formation. Copyright: © 2019 Francikowski et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.},

note = {5},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85047101002,

title = {The ovary organization in the marine limnodriloidin Thalassodrilides cf. briani (Annelida: Clitellata: Naididae) resembles the ovary of freshwater tubificins},

author = { A.Z. Urbisz and Ł. Chajec and M. Ito and K. Ito},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047101002&doi=10.1016%2fj.zool.2018.05.004&partnerID=40&md5=4243bf3fefc68caabe2bec53cda23646},

doi = {10.1016/j.zool.2018.05.004},

issn = {09442006},

year  = {2018},

date = {2018-01-01},

journal = {Zoology},

volume = {128},

pages = {16-26},

publisher = {Elsevier GmbH},

abstract = {In Thalassodrilides cf. briani, the paired ovaries are inconspicuous and polarized structures with developmental gradient of germ cells along their long axis. The about 300 germ cells in the ovary are consolidated into one syncytial cyst and each cell is connected to a common and branched mass of cytoplasm via one stable cytoplasmic bridge. The germ cells differentiate their fate into nurse cells and oocytes. Only one oocyte grows in a given time; it gathers cell organelles and yolk and then it detaches from the gonad. Nurse cells appear to support oocytes development by providing with at least cell organelles. Such observations suggest ovary meroism. T. cf. briani, belonging to limnodriloidin naidids, has the same ovary organization as the representatives of tubificin naidids studied to date. This supports the concept of sister-group relations between Limnodriloidinae and Tubificinae. A similar ovary morphology is also known in several other groups of “microdrile” oligochaetes, which shows that this ovary type is the most widespread among this taxa. Moreover, living in marine or brackish-water sediments, T. cf. briani do not show any significant differences in their ovary structure and oogenesis with freshwater tubificins. This indicates its conservative character independent of the animal life environment. © 2018 Elsevier GmbH},

note = {10},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85034632796,

title = {Micromorphology of ovaries and oogenesis in Grania postclitellochaeta (Clitellata: Enchytraeidae)},

author = { P. Świątek and P. de Wit and X. Unrecognized and Ł. Chajec and A.Z. Urbisz},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85034632796&doi=10.1016%2fj.zool.2017.11.004&partnerID=40&md5=07b1b2c94e7194ec2a2afefdff5487d9},

doi = {10.1016/j.zool.2017.11.004},

issn = {09442006},

year  = {2018},

date = {2018-01-01},

journal = {Zoology},

volume = {126},

pages = {119-127},

publisher = {Elsevier GmbH},

abstract = {The genus Grania comprises over 70 species of exclusively marine clitellate annelids belonging to the family Enchytraeidae. Morphologically, this genus is well separated from other enchytraeids, with thick cuticles, anterior segments I–IV fused into a “head”, chaetal bundles consisting only of one stout chaeta, and reduction of circular musculature. The aim of the present study is to describe the ovary organization and the course of oogenesis in Grania postclitellochaeta, and to compare it with other known systems of ovary organization and oogenesis in clitellate annelids, especially in enchytraeids. Generally, oogenesis in G. postclitellochaeta can be divided into two phases: (i) early stages of oogenesis, occurring within the paired ovaries − each ovary is similar to a bunch of grapes, where each ‘lobe’ is a germ-line cyst enveloped by flat somatic cells, and (ii) oogenesis proper, which takes place within the body lumen where each growing oocyte is accompanied by its own group of nurse cells. Germ cells are interconnected by cytoplasmic channels (intercellular bridges; ring canals) and form syncytial cysts. As in other clitellate annelids, the cyst center contains a common cytoplasm (cytophore) to which each cell is connected by one ring canal only. Initially, within the ovary, all interconnected cells develop synchronously and are morphologically similar. At the time when the cysts detach from the ovary, one of the interconnected cells begins to gather nutrients, grows and becomes an oocyte, whereas the rest of the cells (nurse cells) do not continue meiosis and instead seem to provide the oocyte with macromolecules and cell organelles. Analysis of serial sections reveals that cysts are always composed of 16 cells − one oocyte and fifteen nurse cells. A comparative analysis showed that almost all features of oogenesis in G. postclitellochaeta are similar to that in other representatives of Enchytraeidae (mainly Enchytraeus albidus), suggesting evolutionary conservation of the process across this family. © 2017 Elsevier GmbH},

note = {11},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85027884883,

title = {Food preferences of enchytraeids},

author = { Ł. Gajda and S. Gorgoń and A.Z. Urbisz},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85027884883&doi=10.1016%2fj.pedobi.2017.06.002&partnerID=40&md5=019092ec34bca2ec69199af772c2a57d},

doi = {10.1016/j.pedobi.2017.06.002},

issn = {00314056},

year  = {2017},

date = {2017-01-01},

journal = {Pedobiologia},

volume = {63},

pages = {19-36},

publisher = {Elsevier GmbH},

abstract = {The aim of this review is to evaluate the food sources for enchytraeids and to contribute to the current knowledge of their feeding preferences. Several food sources have been described in detail: (1) plant material, (2) macroalgae, (3) animal remains, (4) feces of invertebrates, (5) bacteria, (6) fungi, (7) microalgae, (8) nematodes, and (9) locust eggs. The present article considers selective ingestion, digestion, and factors affecting enchytraeid food selection. We also provide basic information on enzymatic activity, particularly cellulolytic capability. Recent findings on Cognettia sphagnetorum, which have shown that several cryptic species were hidden under this single species name, shed new light on the somewhat inconsistent data presented in the literature over a long time. Apart from that, the recurrent issue of enchytraeids as plant pests is re-discussed here. This unsupported assumption is still the subject of general agricultural textbooks and requires further clarification. Contrary to old hypotheses, potworms are not plant parasites, and they have little or no cellulolytic capability. Enchytraeids can be divided into two groups: (1) primary decomposers and (2) secondary decomposers/sapro-microphytophages. There is also some evidence, albeit weak, that some species prey on nematodes. So far, the trophic preferences of only a few enchytraeid species have been studied in detail, but it is evident that several feeding strategies exist within the family. These studies include direct observation of feeding behavior, gut content analyses, enzymatic analyses, cultivation on different nutrient sources, choice tests, various types of soil microcosms, litter bags, and isotopic techniques. Molecular methods have been used only occasionally, although they could largely support further necessary research on potworm feeding ecology. © 2017 Elsevier GmbH},

note = {8},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85018650559,

title = {Ovaries of the white worm (Enchytraeus albidus, Annelida, Clitellata) are composed of 16-celled meroistic germ-line cysts},

author = { A.Z. Urbisz and Ł. Chajec and A.J. Brąszewska-Zalewska and J. Kubrakiewicz and P. Świątek},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85018650559&doi=10.1016%2fj.ydbio.2017.04.009&partnerID=40&md5=335b711be43689e8276747bd0ec658e1},

doi = {10.1016/j.ydbio.2017.04.009},

issn = {00121606},

year  = {2017},

date = {2017-01-01},

journal = {Developmental Biology},

volume = {426},

number = {1},

pages = {28-42},

publisher = {Academic Press Inc.},

abstract = {The paired ovaries of E. albidus are like a bunch of grapes and are composed of clearly separated units, syncytial germ cysts (clusters), which are surrounded by a thin layer of somatic cells. Each cyst maintains the connection with the ovary by an extended stalk that is composed of somatic cells. The spatial architecture of the germ-line cysts found in E. albidus is the same as in other clitellate annelids that have been studied to date. As a rule, germ cells are located at the cyst periphery and each has only one ring canal that connects it to the common and centrally located cytoplasmic mass, the cytophore. Here we present data about the F-actin and microtubular cytoskeleton and some molecular components of the germ-line cysts. We show that the ring canals have an inner rim that is enriched with microfilaments and proteins that contain phosphotyrosine. The microtubules form a loose network in the cytoplasm of the oocyte and nurse cells; moreover, some of them pass through the ring canals to the cytophore. Numerous microtubules are also located in the somatic cells. The germ-line cysts in E. albidus ovaries consist of 16 cells, which is the lowest known number of interconnected germ cells within clitellate annelids. During oogenesis, the fate of interconnected germ cells differentiates and only one cell develops as the future egg, while the other 15 become nurse cells. This differentiation means ovary meroism. The nurse cells gather cell organelles and storage material that then pass through the ring canals and cytophore moving towards the growing oocyte. At the end of oogenesis, the vitellogenic oocyte surrounds the siblings’ cells together with the cytophore and engulfs their remnants into the ooplasm. No morphological or molecular markers of the apoptosis of the nurse cells were found. Moreover, the nurse cells did not undergo polyploidisation. The measured DNA level was 4 C, which indicates that these cells are not highly-specialised. © 2017 Elsevier Inc.},

note = {19},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84957310800,

title = {Germ-line cells do not form syncytial cysts in the ovaries of the basal clitellate annelid Capilloventer australis},

author = { P. Świątek and B.J. Płachno and R. Marchant and S. Gorgoń and M. Krodkiewska and K. Małota and A.Z. Urbisz},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84957310800&doi=10.1016%2fj.jcz.2015.12.002&partnerID=40&md5=2d5357896d74db951b3c00c381091acb},

doi = {10.1016/j.jcz.2015.12.002},

issn = {00445231},

year  = {2016},

date = {2016-01-01},

journal = {Zoologischer Anzeiger},

volume = {260},

pages = {63-71},

publisher = {Elsevier GmbH},

abstract = {Capilloventridae are regarded as the putative sister taxon to all other Clitellata. To shed more light on their internal anatomy, we studied the ovary organization and the course of oogenesis in Capilloventer australis. We found that the ovary organization differs substantially from that known in all other clitellate annelids. In contrast to other clitellate annelids, the germ cells in C. australis ovaries develop individually and do not from syncytial cysts. Neither intercellular bridges nor central cytoplasmic mass (cytophore) - structures that are characteristic of gametogenesis in other Clitellata - were found. The paired ovaries of C. australis are located in segment XIII and form chains that are composed of linearly arranged growing germ cells that are covered by a thin envelope of somatic cells. The progression of germ cell development can be observed along the long ovary axis. The ovary tip is occupied by oogonia and below it, previtellogenic and early vitellogenic oocytes occur. Large, vitellogenic oocytes, which are filled with yolk, detach from the ovary and fill the segment lumen. Vitellogenic oocytes are not enveloped by somatic cells. With the exception of the lack of germ-line cyst formation, oogenesis is similar to that found in other Clitellata. It is not clear whether the lack of germ-line cysts is a basal condition for Clitellata that is retained in C. australis or, by contrast, did clitellate annelids inherit a female germ-line cysts from their ancestors and their lack in C. australis is a derived condition? © 2015 Elsevier GmbH.},

note = {12},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84930089679,

title = {Ultrastructural study of spermatogenesis and sperm in the African medicinal leech Hirudo troctina Johnson, 1816 (Annelida, Hirudinida)},

author = { R.B. Ahmed and S. Tekaya and A.Z. Urbisz and P. Świątek},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84930089679&doi=10.1016%2fj.tice.2015.03.002&partnerID=40&md5=4a879fe84b9adb5c59e546ee24fac7f4},

doi = {10.1016/j.tice.2015.03.002},

issn = {00408166},

year  = {2015},

date = {2015-01-01},

journal = {Tissue and Cell},

volume = {47},

number = {3},

pages = {242-253},

publisher = {Churchill Livingstone},

abstract = {This paper presents the process of spermatogenesis in the leech Hirudo troctina Johnson, 1816 using light, fluorescent and transmission electron microscopy. At the onset of spermatogenesis in testes, the pear-shaped spermatogonia divide mitotically without full cytokinesis and as a result isogenic groups are formed (clusters; clones) with 2, 4, 8, 16, 32, 64, 128 spermatogonia and, finally, 256 primary spermatocytes occur. The final meiotic divisions of spermatocytes give rise to clones with 1024 spermatids. There are hundreds of developing germ-line clones in each testis. In each clone, the male germ cells divide in full synchrony and they are in the same phase of spermatogenesis. During complex spermiogenesis each spermatid becomes a filiform spermatozoon with a helicoid nucleus, which is characterized by the presence of a long acrosome with two regions - anterior and posterior, which are followed by a helicoid nucleus, a midpiece with only one mitochondrion and a long flagellum. Our results were compared to those on other clitellate annelids that have been studied to date, especially to sperm formation in Hirudo medicinalis Linnaeus, 1785. Only minor differences were found in the length and the diameter of different organelles and the number of spermatids in germ-line clones. © 2015 Elsevier Ltd.},

note = {3},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84930658502,

title = {The ovary of Tubifex tubifex (Clitellata, Naididae, Tubificinae) is composed of one, huge germ-line cyst that is enriched with cytoskeletal components},

author = { A.Z. Urbisz and Ł. Chajec and P. Świątek},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84930658502&doi=10.1371%2fjournal.pone.0126173&partnerID=40&md5=364f871ae73b8dc8e3876c1aebb06e75},

doi = {10.1371/journal.pone.0126173},

issn = {19326203},

year  = {2015},

date = {2015-01-01},

journal = {PLoS ONE},

volume = {10},

number = {5},

publisher = {Public Library of Science},

abstract = {Recent studies on the ovary organization and oogenesis in Tubificinae have revealed that their ovaries are small polarized structures that are composed of germ cells in subsequent stages of oogenesis that are associated with somatic cells. In syncytial cysts, as a rule, each germ cell is connected to the central cytoplasmic mass, the cytophore, via only one stable intercellular bridge (ring canal). In this paper we present detailed data about the composition of germ-line cysts in Tubifex tubifex with special emphasis on the occurrence and distribution of the cytoskeletal elements. Using fixed material and live cell imaging techniques, we found that the entire ovary of T. tubifex is composed of only one, huge multicellular germ-line cyst, which may contain up to 2,600 cells. Its architecture is broadly similar to the cysts that are found in other clitellate annelids, i.e. a common, anuclear cytoplasmic mass in the center of the cyst and germ cells that are connected to it via intercellular bridges. The cytophore in the T. tubifex cyst extends along the long axis of the ovary in the form of elongated and branched cytoplasmic strands. Rhodamine-coupled phalloidin staining revealed that the prominent strands of actin filaments occur inside the cytophore. Similar to the cytophore, F-actin strands are branched and they are especially well developed in the middle and outermost parts of the ovary. Microfilaments are also present in the ring canals that connect the germ cells with the cytophore in the narrow end of the ovary. Using Tubulin-Tracker, we found that the microtubules form a prominent network of loosely and evenly distributed tubules inside the cytophore as well as in every germ cell. The well-developed cytoskeletal elements in T. tubifex ovary seem to ensure the integrity of such a huge germline cyst of complex (germ cells - ring canals - cytophore) organization. A comparison between the cysts that are described here and other well-known female germ-line cysts is also made. © 2015 Urbisz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.},

note = {14},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84908469233,

title = {Diversity of features of the female reproductive system and other morphological characters in leeches (Citellata, Hirudinida) in phylogenetic conception},

author = { A. Bielecki and P. Świątek and J.M. Cichocka and M.E. Siddall and A.Z. Urbisz and B.J. Płachno},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84908469233&doi=10.1111%2fcla.12058&partnerID=40&md5=2b2c1f80355e42f8028f9fa460e2955e},

doi = {10.1111/cla.12058},

issn = {07483007},

year  = {2014},

date = {2014-01-01},

journal = {Cladistics},

volume = {30},

number = {5},

pages = {540-554},

publisher = {Blackwell Publishing Inc.},

abstract = {An epistemological-evolutionary conception of leeches (Hirudinida) based on features of the female reproductive system in combination with other morphological characters is presented in the spirit of the cladistic school of taxonomy. Characters relating to the structure of the ovary and the course of oogenesis in leeches were interpreted in this manner, for the first time. Each study was conducted on type species of higher taxonomic groups of true leeches. Results of analyses using features of the reproductive system only as well as in combination with other morphological characters show Piscicolidae and Glossiphoniidae as sister clades making Rhynchobdellida a monophyletic group. Also, Hirudiniformes and Erpobdelliformes appeared to be sister clades within Arhynchobdellida. The relationship between the outgroup specimens and leeches remained unresolved, because both Acanthobdella peledina and branchiobdellidans appeared to be in an equivocal relationship to hirudinidans. Characters concerning the structure of the female reproductive system and course of oogenesis thus appeared to be useful, although conservative, for reconstruction of leech phylogeny, and they well reflect phylogenetic relationships of Hirudinida at the family level. © The Willi Hennig Society 2013.},

note = {17},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84898034741,

title = {Barbronia weberi (Clitellata, Hirudinida, Salifidae) has ovary cords of the Erpobdella type},

author = { A.Z. Urbisz and Y.T. Lai and P. Świątek},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84898034741&doi=10.1002%2fjmor.20229&partnerID=40&md5=463a2217741a3d0d35aa435d0dfd079c},

doi = {10.1002/jmor.20229},

issn = {03622525},

year  = {2014},

date = {2014-01-01},

journal = {Journal of Morphology},

volume = {275},

number = {5},

pages = {479-488},

publisher = {John Wiley and Sons Inc.},

abstract = {The organization of the ovaries in representative of the Salifidae (Hirudinida; Erpobdelliformes) was studied at the ultrastructural level for the first time. Like in other leeches, the ovaries of Barbronia weberi are composed of an outer envelope (i.e.; an ovisac made up of two coelomic epithelia; muscle cells; and connective tissue) and several internal units, which are broadly similar to the ovary cords found in representatives of the Erpobdellidae. There are usually 6-8 ovary cords that are twisted or cambered with a narrow apical part and a broader, irregularly shaped distal end in each ovisac of B. weberi. Each ovary cord is built from somatic and germ-line cells and the latter tend to form multicellular cysts that are equipped with a central cytoplasmic core (cytophore). There are two morphologically different subpopulations of germ-line cells: oocytes and more numerous nurse cells. Growing oocytes form protuberances on the ovary cord surface and eventually detach from the cord and float freely in the ovisac lumen, whereas the other components of germ-line cysts (i.e.; nurse cells and cytophore) degenerate. It should be pointed out that there is a prominent gradient of germ-cell development along the long axis of the cord. The somatic cells form the ovary cord envelope (the so-called spongiosa cells) and also penetrate the spaces between germ-line cells. Both kinds of the somatic cells, that is, those forming the cord envelope and the somatic cells that are associated with oocytes (follicular cells) have a well-developed system of intercellular channels. Additionally, one prominent somatic cell, the apical cell, was found at the apical tip of each ovary cord. Because the aforementioned features of ovary cords found in B. weberi are very similar (with a few minor exceptions) to the ovary cords that have been described in Erpobdella octoculata and E. johanssoni, we propose the term "ovary cords of the Erpobdella type" for them. Our results support a close phylogenetic relationship between Salifidae and Erpobdellidae. © 2013 Wiley Periodicals, Inc.},

note = {12},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84875075636,

title = {Ovary organization and oogenesis in two species of Lumbriculida (Annelida, Clitellata)},

author = { A.Z. Urbisz and P. Świątek},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84875075636&doi=10.1016%2fj.zool.2012.10.003&partnerID=40&md5=c1d407a95626f2277bfc2ebb847fcba1},

doi = {10.1016/j.zool.2012.10.003},

issn = {09442006},

year  = {2013},

date = {2013-01-01},

journal = {Zoology},

volume = {116},

number = {2},

pages = {118-128},

abstract = {The aim of the present study is to describe the organization of the ovary and mode of oogenesis at the ultrastructural level in two representatives of Lumbriculida - Lumbriculus variegatus and Stylodrilus heringianus. In both species studied, the ovaries are small and conically shaped structures that are attached to the intersegmental septum via a thin ligament. The ovaries are composed of germline cysts formed by germ cells interconnected by stable cytoplasmic bridges. As a rule, the cyst center is occupied by a poorly developed anuclear cytoplasmic mass, termed a cytophore, whereas the germ cells are located at the periphery of the cyst. Germline cysts are enveloped by somatic cells. The ovaries of the species studied are polarized, i.e., along the long axis of the ovary there is an evident gradient of germ cell development. The data obtained suggest ovary meroism, i.e., two categories of germ cells were found: oocytes, which continue meiosis, gather nutrients, grow and protrude into the body cavity, and nurse cells, which do not grow and are supposed to supply oocytes with cell organelles and macromolecules via the cytophore. The ovary structure and mode of oogenesis in the species studied were compared with those of other clitellate annelids. As a rule, in all clitellates studied to date, the ovaries are composed of germline cysts equipped with a cytophore and associated with somatic cells; however, the ovary morphology differs between taxa regarding several quantitative and qualitative features. The ovary organization and mode of oogenesis in L. variegatus and S. heringianus strongly resemble those found in Tubificinae and Branchiobdellida studied to date. Our results also support a sister-group relationship between Lumbriculida and a clade comprising ectoparasitic clitellates (i.e.; Branchiobdellida; Acanthobdellida and Hirudinida) with Branchiobdellida as a plesiomorphic sister group to Acanthobdellida and Hirudinida. © 2013 Elsevier GmbH.},

note = {22},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84857029800,

title = {Ovary architecture of two branchiobdellid species and Acanthobdella peledina (Annelida, Clitellata)},

author = { P. Świątek and A.Z. Urbisz and W. Strużyński and B.J. Płachno and A. Bielecki and S. Cios and E. Salonen and J. Klag},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84857029800&doi=10.1016%2fj.jcz.2011.08.001&partnerID=40&md5=08e6386d462187c116572001d31dec15},

doi = {10.1016/j.jcz.2011.08.001},

issn = {00445231},

year  = {2012},

date = {2012-01-01},

journal = {Zoologischer Anzeiger},

volume = {251},

number = {1},

pages = {71-82},

publisher = {Elsevier GmbH},

abstract = {The aim of this study was to present data about ovary organization and oogenesis in two small groups of clitellate annelids, i.e. in representatives of Acanthobdellida (Acanthobdella peledina) and Branchiobdellida (Branchiobdella pentodonta and Branchiobdella parasitica), and to compare them to ovaries known from true leeches and oligochaetous clitellates. In A. peledina, the ovaries have the form of elongated cords, termed ovary cords, and are enveloped by coelomic sacs, the so-called ovisacs. The ovisacs are paired and each one contains only one ovary cord. The morphology and structure of the ovary cords depend on the maturity level of the animal. In young specimens the ovary cords are short and contain mainly oogonial cells and germ cells entering meiosis. Oogonia divide mitotically without full cytokineses, and as a result germ-line cysts are formed. As the animals grow, the cords become more elongated and the germ cells within the cords differentiate into nurse cells and oocytes. Oocytes gather cell organelles and, finally, detach from the ovary cord and float freely in the ovisac lumen.In both examined branchiobdellidans the ovaries are also paired. They are short and conical and are not enclosed within ovisacs. The narrow end of each ovary is connected to the intersegmental septum via a ligament, whereas the outermost (broad) end of the ovary extends freely into the coelom. The ovaries are polarized. Their narrow ends contain oogonia, whereas nurse cells and growing oocytes, gradually projecting from the ovary, can be found in their middle and outermost parts. Early vitellogenic oocytes detach from the ovary and float freely in the coelom.In all of the species studied, the ovaries are made up of germ-line cysts associated with somatic (follicular) cells. The architecture of a germ-line cyst is exactly the same as in other clitellate annelids that have been studied to date. Each germ cell in a cyst has one stable cytoplasmic bridge connecting it with a central anuclear cytoplasmic mass, a cytophore. The fate of germ cells constituting cysts is diverse. The majority of the cells withdraw from meiosis and become nurse cells; only a few continue meiosis, grow and become oocytes. The meroistic mode of oogenesis is suggested. We suggest also that the formation of germ-line cysts and ovary meroism should be regarded as basal conditions for all Clitellata. The occurrence of ovisacs enveloping the ovaries in A. peledina and Hirudinida is regarded as a synapomorphy of both groups, whereas ovaries found in B. pentodonta and B. parasitica have no ovisacs and resemble ovaries described in Oligochaeta sensu stricto. © 2011 Elsevier GmbH.},

note = {26},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-78649648878,

title = {Ovaries of Tubificinae (Clitellata, Naididae) resemble ovary cords found in Hirudinea (Clitellata)},

author = { A.Z. Urbisz and M. Krodkiewska and P. Świątek},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78649648878&doi=10.1007%2fs00435-010-0116-6&partnerID=40&md5=01ee3d55eec778caf21c433c3281d97f},

doi = {10.1007/s00435-010-0116-6},

issn = {0720213X},

year  = {2010},

date = {2010-01-01},

journal = {Zoomorphology},

volume = {129},

number = {4},

pages = {235-247},

publisher = {Springer Verlag},

abstract = {The ultrastructure of the ovaries and oogenesis was studied in three species of three genera of Tubificinae. The paired ovaries are small, conically shaped structures, connected to the intersegmental septum between segments X and XI by their narrow end. The ovaries are composed of syncytial cysts of germ cells interconnected by stable cytoplasmic bridges (ring canals) and surrounded by follicular cells. The architecture of the germ-line cysts is exactly the same as in all clitellate annelids studied to date, i. e. each cell in a cyst has only one ring canal connecting it to the central, anuclear cytoplasmic mass, the cytophore. The ovaries found in all of the species studied seem to be meroistic, i. e. the ultimate fate of germ cells within a cyst is different, and the majority of cells withdraw from meiosis and become nurse cells; the rest continue meiosis, gather macromolecules, cell organelles and storage material, and become oocytes. The ovaries are polarized; their narrow end contains mitotically dividing oogonia and germ cells entering the meiosis prophase; whereas within the middle and basal parts, nurse cells, a prominent cytophore and growing oocytes occur. During late previtellogenesis/early vitellogenesis, the oocytes detach from the cytophore and float in the coelom; they are usually enveloped by the peritoneal epithelium and associated with blood vessels. Generally, the organization of ovaries in all of the Tubificinae species studied resembles the polarized ovary cords found within the ovisacs of some Euhirudinea. The organization of ovaries and the course of oogenesis between the genera studied and other clitellate annelids are compared. Finally, it is suggested that germ-line cysts formation and the meroistic mode of oogenesis may be a primary character for all Clitellata. © 2010 The Author(s).},

note = {20},

keywords = {},

pubstate = {published},

tppubtype = {article}

}