title: Male meiosis in Crustacea: synapsis, recombination, epigenetics and fertility in Daphnia magna.
abstract: We present the first detailed cytological study of male meiosis in Daphnia (Crustacea: Branchiopoda: Cladocera)-an aquatic microcrustacean with a cyclical parthenogenetic life cycle. Using immunostaining of the testes in Daphnia magna for baseline knowledge, we characterized the different stages of meiotic division and spermiogenesis in relation to the distribution of proteins involved in synapsis, early recombination events and sister chromatid cohesion. We also studied post-translational histone modifications in male spermatocytes, in relation to the dynamic chromatin progression of meiosis. Finally, we applied a DNA fragmentation test to measure sperm quality of D. magna, with respect to levels of inbreeding. As a proxy for fertility, this technique may be used to assess the reproductive health of a sentinel species of aquatic ecosystems. Daphnia proves to be a model species for comparative studies of meiosis that is poised to improve our understanding of the cytological basis of sexual and asexual reproduction.
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049, Madrid, Spain. rocio.gomez@uam.es.|Environmental Genomics Group. School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK. rocio.gomez@uam.es.|Chromosome Dynamics Group. School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK. rocio.gomez@uam.es.
authors.forename: Rocío
authors.initials: R
authors.lastname: Gómez
authors.affiliation: Environmental Genomics Group. School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK.
authors.forename: Kay
authors.initials: K
authors.lastname: Van Damme
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049, Madrid, Spain.
authors.forename: Jaime
authors.initials: J
authors.lastname: Gosálvez
authors.affiliation: Chromosome Dynamics Group. School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK.
authors.forename: Eugenio Sánchez
authors.initials: ES
authors.lastname: Morán
authors.affiliation: Environmental Genomics Group. School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK.
authors.forename: John K
authors.initials: JK
authors.lastname: Colbourne
mesh_terms: D000818:Animals; D023902:Chromosome Pairing / Q000502:physiology*; D020090:Chromosome Segregation / Q000502:physiology*; D003621:Daphnia / Q000502:physiology*; D044127:Epigenesis, Genetic / Q000235:genetics*; D005298:Fertility / Q000502:physiology; D006657:Histones / Q000378:metabolism; D008297:Male; D008540:Meiosis / Q000502:physiology*; D010312:Parthenogenesis / Q000235:genetics; D011499:Protein Processing, Post-Translational; D012098:Reproduction; D013090:Spermatocytes / Q000166:cytology; D013091:Spermatogenesis / Q000502:physiology*
chemical_list: D006657:Histones
keywords: Daphnia; Epigenomics; Fertility; Meiosis; Recombination; Synapsis