①.Spermatocytogenesis:MitosisSpermatogoniaprimaryspermatocytes②.Meiosis:Meiosis I+2secondaryspermatocytesprimary spermatocyte?Meiosis II+4spermatids(44+X+Y)③.Spermiogenesis(44+X+Y)田(22+XorY)no divisionSpermatidsspermatozoaY-(22+XorY)Modifystructure&shape(22+XorY)
Spermatogonia primary spermatocytes primary spermatocyte 2 secondary spermatocytes 4 spermatids ①. Spermatocytogenesis: ②. Meiosis: Mitosis Meiosis Ⅰ Meiosis Ⅱ ③.Spermiogenesis Spermatids spermatozoa no division Modify structure& shape
TypeAspermatogonia(stemcells)TypeBspermatogonia(progenitorcell)44+X+Y(2nDNA)Mitosis(Spermatocytogenesis）44+X+Y(4nDNA)PrimaryspermatocytesFirstmeiotic divisionSecondaryspermatocytes22+X/Y (2nDNA)00Secondmeioticdivisior00000000000022+X/Y(1nDNA)HesloualpoolesSpermatidsSpermiogenesisResidualbodiesSpermatozoa
44+X+Y (2n DNA) 44+X+Y (4nDNA) (Spermatocytogenesis) 22+X/Y (2nDNA) 22+X/Y (1nDNA)
Prophaseofthefirstmeiosisprimaryspermatocytereplicate46,XYDNA46,XY(4nDNA)(2nDNA)SecondaryspermatidspermatocytetelophaseMetaphaseThesecond meiosis-anaphaseWithoutreplicationofDNA23,X/Y23,X/Y(1nDNA)(2nDNA)UD
精原细胞 初级精母细胞 Prophase of the first meiosis replicate DNA primary spermatocyte 46,XY (4nDNA) 46,XY (2nDNA) 次级精母细胞 精子细胞 精子 The second meiosis Without replication of DNA Secondary spermatocyte telophase spermatid Metaphase -anaphase 23,X/Y (2nDNA) 23,X/Y (1nDNA)
no divisionSpermatidsspermatozoaModifystructure&shapeAcrosomalgranuleAcrosomalvesicleAcrosomalcapAcrosomeGolgiNucleusNucleusaS食RMiddleOUDOpiece86CentriolesMitochondrionResidualbodiesMitochondriaAcrosomeaS5m公05μm50μm5μm5μmHeadEndpiecePrincipalpieceMiddlepiece
Spermatids spermatozoa no division Modify structure& shape