title: Spermatid development in XO male mice with varying Y chromosome short-arm gene content: evidence for a Y gene controlling the initiation of sperm morphogenesis.
abstract: We recently used three XO male mouse models with varying Y short-arm (Yp) gene complements, analysed at 30 days post partum, to demonstrate a Yp gene requirement for the apoptotic elimination of spermatocytes with a univalent X chromosome at the first meiotic metaphase. The three mouse models were i) XSxr(a)O in which the Yp-derived Tp(Y)1Ct(Sxr-a) sex reversal factor provides an almost complete Yp gene complement, ii) XSxr(b)O,Eif2s3y males in which Tp(Y)1Ct(Sxr-b) has a deletion completely or partially removing eight Yp genes - the Yp gene Eif2s3y has been added as a transgene to support spermatogonial proliferation, and iii) XOSry,Eif2s3y males in which the Sry transgene directs gonad development along the male pathway. In this study, we have used the same mouse models analysed at 6 weeks of age to investigate potential Yp gene involvement in spermiogenesis. We found that all three mouse models produce haploid and diploid spermatids and that the diploid spermatids showed frequent duplication of the developing acrosomal cap during the early stages. However, only in XSxr(a)O males did spermiogenesis continue to completion. Most strikingly, in XOSry,Eif2s3y males, spermatid development arrested at round spermatid step 7 so that no sperm head restructuring or tail development was observed. In contrast, in XSxr(b)O,Eif2s3y males, spermatids with substantial sperm head and tail morphogenesis could be easily found, although this was delayed compared with XSxr(a)O. We conclude that Sxr(a) (and therefore Yp) includes genetic information essential for sperm morphogenesis and that this is partially retained in Sxr(b).
authors.affiliation: Division of Stem Cell Biology and Developmental Genetics, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK. vernet.nadege@gmail.com
authors.forename: Nadège
authors.initials: N
authors.lastname: Vernet
authors.forename: Shantha K
authors.initials: SK
authors.lastname: Mahadevaiah
authors.forename: Peter J I
authors.initials: PJ
authors.lastname: Ellis
authors.forename: Dirk G
authors.initials: DG
authors.lastname: de Rooij
authors.forename: Paul S
authors.initials: PS
authors.lastname: Burgoyne
mesh_terms: D000177:Acrosome / Q000378:metabolism / Q000473:pathology; D000818:Animals; D002872:Chromosome Deletion; D041322:Chromosomes, Human, Y / Q000378:metabolism; D003433:Crosses, Genetic; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D015852:Eukaryotic Initiation Factor-2 / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D050173:Genes, Y-Linked; D007248:Infertility, Male; D008297:Male; D008540:Meiosis; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012729:Sex Chromosome Aberrations; D058533:Sex Chromosome Disorders of Sex Development / Q000378:metabolism* / Q000473:pathology; D051876:Sex-Determining Region Y Protein / Q000235:genetics / Q000378:metabolism*; D013082:Sperm Tail / Q000378:metabolism / Q000473:pathology; D013087:Spermatids / Q000378:metabolism* / Q000473:pathology; D013091:Spermatogenesis; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D015852:Eukaryotic Initiation Factor-2; D011993:Recombinant Fusion Proteins; D051876:Sex-Determining Region Y Protein; C497746:Sry protein, mouse; D014157:Transcription Factors; C501342:Zfy1 protein, mouse; C501343:Zfy2 protein, mouse