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Hosseini Khorami H, Breton S, Angers A. In vitro proliferation of Mytilus edulis male germ cell progenitors. PLoS One 2024; 19:e0292205. [PMID: 38335194 PMCID: PMC10857695 DOI: 10.1371/journal.pone.0292205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 01/09/2024] [Indexed: 02/12/2024] Open
Abstract
Our understanding of basic cellular processes has mostly been provided by mammalian cell culture, and by some non-mammalian vertebrate and few invertebrate cell culture models. Developing reliable culture conditions for non-model organisms is essential to allow investigation of more unusual cellular processes. Here, we investigate how cells isolated from different tissues of the marine mussel Mytilus edulis thrive and survive in vitro in the hope of establishing a suitable laboratory model for the investigation of cellular mechanisms specific to these bivalve mollusks. We found that cells dissociated from mantle tissue attached to the culture vessels and proliferated well in vitro, whereas cells isolated from gills, although remaining viable, did not maintain divisions over three to four weeks in culture. We used antibodies against the germ-line marker DEAD-box helicase 4 (DDX4), also known as VASA, and the epithelial cell marker cytokeratin to distinguish different cell types in culture. DDX4-positive cells were predominant in 25-day-old cultures from male mantles. Cells from other tissues remained in low numbers and did not seem to change in composition over time. Overall, the culture conditions described here allow an efficient selection of male germ cells that could be used to study specific cellular mechanisms in vitro.
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Affiliation(s)
| | - Sophie Breton
- Département de Sciences Biologiques, Université de Montréal, Montréal, Québec, Canada
| | - Annie Angers
- Département de Sciences Biologiques, Université de Montréal, Montréal, Québec, Canada
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2
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Ross SE, Vázquez-Marín J, Gert KRB, González-Rajal Á, Dinger ME, Pauli A, Martínez-Morales JR, Bogdanovic O. Evolutionary conservation of embryonic DNA methylome remodelling in distantly related teleost species. Nucleic Acids Res 2023; 51:9658-9671. [PMID: 37615576 PMCID: PMC10570028 DOI: 10.1093/nar/gkad695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/28/2023] [Accepted: 08/09/2023] [Indexed: 08/25/2023] Open
Abstract
Methylation of cytosines in the CG context (mCG) is the most abundant DNA modification in vertebrates that plays crucial roles in cellular differentiation and identity. After fertilization, DNA methylation patterns inherited from parental gametes are remodelled into a state compatible with embryogenesis. In mammals, this is achieved through the global erasure and re-establishment of DNA methylation patterns. However, in non-mammalian vertebrates like zebrafish, no global erasure has been observed. To investigate the evolutionary conservation and divergence of DNA methylation remodelling in teleosts, we generated base resolution DNA methylome datasets of developing medaka and medaka-zebrafish hybrid embryos. In contrast to previous reports, we show that medaka display comparable DNA methylome dynamics to zebrafish with high gametic mCG levels (sperm: ∼90%; egg: ∼75%), and adoption of a paternal-like methylome during early embryogenesis, with no signs of prior DNA methylation erasure. We also demonstrate that non-canonical DNA methylation (mCH) reprogramming at TGCT tandem repeats is a conserved feature of teleost embryogenesis. Lastly, we find remarkable evolutionary conservation of DNA methylation remodelling patterns in medaka-zebrafish hybrids, indicative of compatible DNA methylation maintenance machinery in far-related teleost species. Overall, these results suggest strong evolutionary conservation of DNA methylation remodelling pathways in teleosts, which is distinct from the global DNA methylome erasure and reestablishment observed in mammals.
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Affiliation(s)
- Samuel E Ross
- Garvan Institute of Medical Research, Sydney, Australia
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
- School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Javier Vázquez-Marín
- Centro Andaluz de Biología del Desarrollo, CSIC-Universidad Pablo de Olavide-Junta de Andalucía, Seville, Spain
| | - Krista R B Gert
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, A-1030, Vienna, Austria
| | - Álvaro González-Rajal
- Garvan Institute of Medical Research, Sydney, Australia
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Marcel E Dinger
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
- School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Andrea Pauli
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, Vienna, Austria
| | - Juan Ramon Martínez-Morales
- Centro Andaluz de Biología del Desarrollo, CSIC-Universidad Pablo de Olavide-Junta de Andalucía, Seville, Spain
| | - Ozren Bogdanovic
- Garvan Institute of Medical Research, Sydney, Australia
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
- Centro Andaluz de Biología del Desarrollo, CSIC-Universidad Pablo de Olavide-Junta de Andalucía, Seville, Spain
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Function of leukaemia inhibitory factor in spermatogenesis of a teleost fish, the medaka Oryzias latipes. ZYGOTE 2019; 27:423-431. [PMID: 31617472 DOI: 10.1017/s0967199419000558] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In response to gonadotropins and androgens, testicular cells produce various molecules that control proper proliferation and differentiation of spermatogenic cells through their paracrine and autocrine actions. However, molecules functioning downstream of the hormonal stimulation are poorly understood. Leukaemia inhibitory factor (Lif) is known to maintain the pluripotency of stem cells including embryonic stem cells and primordial germ cells at least in vitro, but its actual roles in vivo remain to be elucidated. To clarify the function of Lif in teleost (medaka) testes, we examined the effects of Lif on spermatogenesis in a newly established cell culture system using a cell line (named Mtp1) derived from medaka testicular somatic cells as feeder cells. We found that addition of baculovirus-produced recombinant medaka Lif to the culture medium or co-culture with Lif-overexpressing Mtp1 cells increased the number of spermatogonia. In situ hybridization and immunohistochemical analyses of the medaka testes showed that mRNAs and proteins of Lif are expressed in spermatogonia and the surrounding Sertoli cells, with higher expression levels in type A (undifferentiated) spermatogonia than in type B (differentiated) spermatogonia. Our findings suggest that Lif regulates spermatogonial cell proliferation in the medaka.
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Lu Y, Aitken RJ, Lin M. Ultrastructural investigation and in vitro recapitulation of spermatid differentiation in a potential bio-indicator species - The marine invertebrate Galeolaria gemineoa (Polychaeta: Serpulidae). PLoS One 2017; 12:e0183986. [PMID: 28850628 PMCID: PMC5574576 DOI: 10.1371/journal.pone.0183986] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Accepted: 08/15/2017] [Indexed: 11/21/2022] Open
Abstract
Galeolaria gemineoa is a sessile broadcast-spawning marine invertebrate, whose spermatozoa have been regarded as a sensitive indicator for water quality monitoring. In this study, 10 steps of spermiogenesis have been identified at the ultrastructural level and this differentiation process has been recapitulated in vitro up to the point of spermiogenesis (step 7-9 spermatids). On completion of the second meiosis, newly formed spermatids were detached from the seminiferous epithelium and released to the lumen of each germinal chamber. These spermatids were present in pairs and interconnected by a cytoplasmic bridge throughout the entire spermiogenic process. On the basis of morphological events such as formation of the acrosome, elongation of the flagellum, and condensation of the nucleus, spermiogenesis has been temporally divided into Golgi phase, acrosomal phase and maturation phase. During the Golgi phase, proacrosomal vesicles appeared at the posterior pole of the spermatids and gradually fused into a proacrosomal vacuole. Simultaneously, the distal centriole docked onto the plasma membrane and gave rise to a formative flagellum. The acrosomal phase was characterised by differentiation of the acrosome, condensation of the chromatin and formation of a mitochondrial sheath surrounding the initial portion of the flagellum. During the maturation phase, the fully differentiated acrosome migrated to the anterior pole and excess cytoplasm was extruded from the spermatids in the form of residual bodies. In addition, we successfully induced step 1-3 spermatids to differentiate into the step 7-9 spermatids in both male germinal fluid and 10% foetal bovine serum in RPMI 1640 medium, but failed to replicate this process in female or boiled male germinal fluids. This finding supports our concept that spermatid differentiation in this species is dependent on intrinsic developmental programming and does not require input from accompanying nurse cells.
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Affiliation(s)
- Yonggang Lu
- Priority Research Centre for Reproductive Science, School of Environmental and Life Sciences, Faculty of Science, University of Newcastle, Callaghan, New South Wales, Australia
| | - Robert John Aitken
- Priority Research Centre for Reproductive Science, School of Environmental and Life Sciences, Faculty of Science, University of Newcastle, Callaghan, New South Wales, Australia
| | - Minjie Lin
- Priority Research Centre for Reproductive Science, School of Environmental and Life Sciences, Faculty of Science, University of Newcastle, Callaghan, New South Wales, Australia
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Guan G, Sun K, Zhang X, Zhao X, Li M, Yan Y, Wang Y, Chen J, Yi M, Hong Y. Developmental tracing of oocyte development in gonadal soma-derived factor deficiency medaka (Oryzias latipes) using a transgenic approach. Mech Dev 2017; 143:53-61. [PMID: 28093265 DOI: 10.1016/j.mod.2016.12.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/25/2016] [Accepted: 12/26/2016] [Indexed: 11/21/2022]
Abstract
Gonadal soma-derived factor (gsdf) is reported to be a male initiator in medaka based on loss- and gain- of function via targeted disruption, or transgenic over-expression. However, little is known about how gsdf promotes undifferentiated gonad entry into male pathways or prevents entry into the female pathway. We utilized a visible folliculogenesis system with a reporter cassette of dual-color fluorescence expression to identify difference between oocyte development from wildtype and gsdf deficiency medaka. A red fluorescent protein (RFP) is driven by a major component of the synaptonemal complex (SYCP3) promoter which enables RFP expression solely in oocytes after the onset of meiosis, and a histone 2b-EGFP fused protein (H2BEGFP) under the control of an elongation factor (EF1α) promoter, wildly used as a mitotic reporter of cell cycle. This mitosis-meiosis visible switch revealed that early meiotic oocytes present in gsdf deficiency were more than those in wildtype ovaries, corresponding to the decrease of inhibin expression detected by real-time qPCR analysis, suggesting gsdf is tightly involved in the process of medaka oocyte development at early stage.
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Affiliation(s)
- Guijun Guan
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai 201306, China.
| | - Kaiqing Sun
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai 201306, China
| | - Xi Zhang
- Department of Biological Sciences, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
| | - Xiaomiao Zhao
- Reproductive Endocrinology & Infertility, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Yanjiang Road 107, Guangdong 510120, China
| | - Mingyou Li
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai 201306, China
| | - Yan Yan
- Department of Biological Sciences, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
| | - Yunzhi Wang
- Department of Biological Sciences, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
| | - Jianbin Chen
- Department of Biological Sciences, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
| | - Meisheng Yi
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Zhuhai Key Laboratory of Marine Bioresources and Environment, School of Marine Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yunhan Hong
- Department of Biological Sciences, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
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Li X, Liu J, Zhang Y. Octylphenol induced gene expression in testes of Frog, Rana chensinensis. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2016; 128:75-82. [PMID: 26896894 DOI: 10.1016/j.ecoenv.2016.02.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 02/11/2016] [Accepted: 02/11/2016] [Indexed: 06/05/2023]
Abstract
Octylphenol (OP) is an endocrine-disrupting chemical (EDC), which can disrupt the reproductive system. To understand the effect of OP, a subtractive cDNA library was constructed using suppression subtractive hybridization (SSH) to identify alterations of gene transcription in the testes of the frog Rana chensinensis after OP exposure. Two hundred positive clones were selected and 134 sequences of gene fragments were produced from the subtractive library randomly. These genes were identified to be involved in metabolic process, cellular process, biological regulation, stimulus, immune system and female pregnancy process. In order to verify the efficiency of the subtractive cDNA library, PSG9 and PAPP-A were analyzed further as two representatives of differentially expressed transcription genes using semi-quantitative RT-PCR. Our result was the first successful construction of the subtractive cDNA library in frog testes after OP treatment. Based on this cDNA library, OP was shown to affect multiple physiological processes including inducing immune response, disrupting the steroid hormone synthesis and influencing spermatogenesis in the testis by up-regulation of specific genes.
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Affiliation(s)
- Xinyi Li
- Co-Innovation Center for Qinba Regions'Sustainable Development, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710062, China
| | - Jia Liu
- Co-Innovation Center for Qinba Regions'Sustainable Development, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710062, China
| | - Yuhui Zhang
- Co-Innovation Center for Qinba Regions'Sustainable Development, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710062, China.
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Iwasaki Y, Ohkawa K, Sadakata H, Kashiwadate A, Takayama-Watanabe E, Onitake K, Watanabe A. Two states of active spermatogenesis switch between reproductive and non-reproductive seasons in the testes of the medaka, Oryzias latipes. Dev Growth Differ 2009; 51:521-32. [PMID: 21314670 DOI: 10.1111/j.1440-169x.2009.01114.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Seasonal change in spermatogenesis was examined in the restricted spermatogonium-type testes of a teleost, Oryzias latipes. Histological observation revealed that the number of each stage of germ cells during most of the non-reproductive season, from October to January (O-J period) was nearly half of that during the reproductive season, from May to July (M-J period), except for type B spermatogonia (B-gonia), which was actually equal. As a result, the ratio of primary spermatocytes (P-cytes) to B-gonia was remarkably small in the O-J period. Despite the differences between both time periods, the proliferative activity of type A spermatogonia (A-gonia), B-gonia, or P-cytes was at a similar level in both periods. Moreover, in cultured testes treated with bromodeoxyuridine as a cell-lineage tracer, P-cytes differentiated to spermatids in 11-15 days in both M-J and O-J periods. These indicate that spermatogenesis is active in each period at a different state. In the spermatogenic testis, A-gonial proliferation was maintained by human follicle stimulating hormone/luteinizing hormone in culture. Whereas cell death of B-gonia and/or P-cytes gradually increased in the M-J period in spite of those cells being constant in population sizes. In transition to the O-J period, A-gonia and P-cytes first decreased, which was accompanied by a decrease in proliferative activity of A-gonia and relative increase of dead cells from B-gonia and/or P-cytes against live P-cytes. These suggest that A-gonial proliferation and cell death of B-gonia and/or P-cytes that is induced coordinately with B-gonial differentiation are critical for the spermatogenic control.
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Affiliation(s)
- Yuko Iwasaki
- Department of Biology, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560, Japan
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Iwai T, Inoue S, Kotani T, Yamashita M. Production of transgenic medaka fish carrying fluorescent nuclei and chromosomes. Zoolog Sci 2009; 26:9-16. [PMID: 19267607 DOI: 10.2108/zsj.26.9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
As with zebrafish, attention has focused on the teleost medaka Oryzias latipes as an experimental animal representative of non-mammalian vertebrates in various fields of biological science. To enable real-time analyses of the dynamics of nuclei and chromosomes in living medaka cells, we produced a transgenic medaka expressing a fusion protein between histone H2B and green fluorescent protein (GFP) under the control of a cytomegalovirus (CMV) promoter. Since the nuclei and chromosomes of transgenic medaka cells are labeled with GFP, their morphological changes can be instantly monitored throughout the mitotic cell cycle progression under a fluorescent microscope without any fixation and staining of samples. However, GFP-labeling of nuclei and chromosomes is not successful during early embryonic development until zygotic expression begins and during the meiotic cell cycle progression, because the CMV promoter does not work in these stages. In addition, histone H2B-GFP fusion proteins are expressed in an organ-specific manner; strong and ubiquitous expression occurs in cells comprising the gut and fin, whereas the expression is restricted to certain types of cells in the liver and brain. These findings suggest that the CMV-driven expression of the histone H2B-GFP transgene is modified depending on the integration site of the transgene in the genome. Nevertheless, easy and precise monitoring of cytological changes in nuclei and chromosomes in the majority of mitotic cells by using the transgenic medaka will greatly contribute to a better understanding of control mechanisms of nuclear and chromosomal behaviors in vertebrate cells.
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Affiliation(s)
- Toshiharu Iwai
- Laboratory of Reproductive and Developmental Biology, Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810, Japan
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González-Doncel M, Okihiro MS, Torija CF, Tarazona JV, Hinton DE. An artificial fertilization method with the Japanese medaka: implications in early life stage bioassays and solvent toxicity. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2008; 69:95-103. [PMID: 17291584 DOI: 10.1016/j.ecoenv.2006.12.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2005] [Revised: 12/07/2006] [Accepted: 12/17/2006] [Indexed: 05/13/2023]
Abstract
An in vitro fertilization method was used to study the effects on medaka (Oryzias latipes) embryos reared either from 0.5h (early blastodisc) or 6.5h (early blastula) post-fertilization for 200 h in varying concentrations of dimethyl sulfoxide (DMSO), methanol, or ethanol (0.06, 0.13, 0.25, 0.50, 1.00, 1.50, and 2.00% v/v). Physiological and anatomical parameters in embryos and larvae were examined and compared across groups. Among the three solvents, ethanol induced the most severe effects in embryos and larvae. Based on anatomical abnormalities, no differences were observed between both windows of exposure to DMSO. Similarly, no differences were observed at concentrations of methanol or ethanol 0.25% v/v. Only two endpoints, hatching success for methanol (EC50 1.84% v/v), and spinal deformities in larvae for ethanol (EC50 0.60% v/v) pointed the earlier window of exposure as significantly more sensitive. Further research is needed to investigate if using this exposure methodology for chemicals with more specific modes of action may result in increased sensitivities.
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Affiliation(s)
- Miguel González-Doncel
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA.
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Partial formation of sperm dimorphism from spermatocytes of the cottoid fish, Hemilepidotus gilberti in cell culture. ZYGOTE 2007; 15:285-93. [PMID: 17967208 DOI: 10.1017/s0967199407004364] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Polymorphism of sperm is considered to be significant for the reproductive strategy in some animal species. The phenomenon is thought to occur in the species-specific stage of spermatogenesis, but how the identical germ cells are differentiated towards polymorphic sperm remains unknown. We here performed a germ cell culture in the cottoid fish, Hemilepidotus gilberti, whose sperm exhibit dimorphism with fertilizable eusperm and unfertilizable parasperm. In the culture, germ cells, which were obtained with an identical morphology, a spherical shape of 5-7 microm in diameter, differentiated into smaller spherical cells with a single nucleus, a moving flagellum and localized mitochondria. In addition, large retroflex-shaped cells with two elongated nuclei were also observed in the cell culture. Germ cells that had each morphological feature were histologically also observed in some cysts of the spermatogenetic testis, suggesting that the former type of cell corresponded to developing eusperm and the latter corresponded to developing parasperm. When BrdU was incorporated into germ cells in the culture, it was detected in both cells with eusperm-like and those with parasperm-like morphologies. These findings suggest that DNA-duplicating spermatocytes are potent to autonomously progress a part of spermatogenesis to form dimorphic sperm.
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Yoshikawa H, Morishima K, Kusuda S, Yamaha E, Arai K. Diploid sperm produced by artificially sex-reversed clone loaches. ACTA ACUST UNITED AC 2007; 307:75-83. [PMID: 17177281 DOI: 10.1002/jez.a.337] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Clone loaches reproduce unisexually in a wild population of Hokkaido Island, Japan. These clone loaches produce genetically identical unreduced eggs which develop to diploid individuals without any genetic contribution of sperm donors. In the present study, sex reversal of clone loaches was attempted and the reproductive potential of resultant clone males was examined. Clone loaches administered 0.5 ppm of 17-alpha methyltestosterone (MT) for 30 days from 1 month after hatching differentiated into physiological males. These sex-reversed clone males produced fertile spermatozoa with a diploid DNA content. Diploid spermatozoa had significantly larger heads than normal haploid sperm, but had a normal shape showing a head, mid-piece, and tail. The motility of diploid spermatozoa was low after ambient water was added. Concentration of diploid spermatozoa per unit of sperm was lower than that of control haploid spermatozoa. Microsatellite genotyping revealed that triploid progeny from the cross between a normal diploid female and a sex-reversed clone male had two alleles specific to the diploid clone male and one allele of the mother loach. These results indicated that the sex-reversed clone males produced fertile diploid spermatozoa genetically identical to the clone lineage.
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Affiliation(s)
- Hiroyuki Yoshikawa
- Graduate School of Fisheries Sciences, Hokkaido University, Hakodate 041-8611, Japan.
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Iwai T, Yoshii A, Yokota T, Sakai C, Hori H, Kanamori A, Yamashita M. Structural components of the synaptonemal complex, SYCP1 and SYCP3, in the medaka fish Oryzias latipes. Exp Cell Res 2006; 312:2528-37. [PMID: 16764855 DOI: 10.1016/j.yexcr.2006.04.015] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2005] [Revised: 04/19/2006] [Accepted: 04/23/2006] [Indexed: 11/23/2022]
Abstract
The synaptonemal complex (SC) is a meiosis-specific structure essential for synapsis of homologous chromosomes. For the first time in any non-mammalian vertebrates, we have isolated cDNA clones encoding two structural components of the SC, SYCP1 and SYCP3, in the medaka, and investigated their protein expression during gametogenesis. As in the case of mammals, medaka SYCP1 and SYCP3 are expressed solely in meiotically dividing cells. In the diplotene stage, SYCP1 is diminished at desynaptic regions of chromosomes and completely lost on the chromosomes at later stages. SYCP3 is localized along the arm and centromeric regions of chromosomes at metaphase I, and its existence on the whole chromosomes persists up to anaphase I, a situation different from that reported in the mouse, in which SYCP3 is confined to the centromeric regions but lost on the arm regions at metaphase I. Thus, the expression patterns of SC components are different in mammals and fish despite the resemblance in morphological structure of the SC, suggesting divergence in the function of the SC in regulation of meiosis-specific chromosomal behavior. Since the antibody against medaka SYCP3 is cross-reactive to other fishes, it should be generally useful for a meiosis-specific marker in fish germ cells.
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Affiliation(s)
- Toshiharu Iwai
- Laboratory of Molecular and Cellular Interactions, Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810, Japan
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