Animal Science 434 Reproductive PhysiologyDevelopment of the Pituitary GlandPowerPoint PresentationSlide 4Slide 5Slide 6Slide 7Slide 8Slide 9Fetal KidneysDevelopment of Mesenephros and MetenephrosSlide 12Jost ExperimentsSlide 14Slide 15Chromosomal SexSlide 17Slide 18Slide 19Human X and Y ChromosomesSlide 21The Y Chromosome Cont.SRY and BirdsGonadal SexSlide 25Slide 26Slide 27Primary Sex Chords in Fetal TestisHormonal SexSlide 30Slide 31Slide 32Slide 33Slide 34Female DevelopmentSlide 36Slide 37Slide 38Slide 392nd Sex Chords in Fetal OvarySlide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47Phenotypic SexSlide 49Slide 50Slide 51Slide 52Animal Science 434Reproductive PhysiologyAnimal Science 434Reproductive PhysiologyLec 5: Embryogenesis of the Pituitary and Sexual DevelopmentLec 5: Embryogenesis of the Pituitary and Sexual DevelopmentDevelopment of the Pituitary GlandStomodeumRathke’s PouchInfundibulumInfundibulumBrainMigration begins by the 4 week of gestation in cow and human.Germ Cell MigrationMigration from endodermthrough mesoderm.In birds the migration is via the blood stream.Fetal Kidneys•Pronephros»regresses•Mesonephros»portions of reproductive tract•Metenephros»Adult kindney and urinary ductsDevelopment of Mesenephros and MetenephrosDevelopment of Mesenephros and MetenephrosEarly Development Flash Moviehttp://www.ansci.wisc.edu/jjp1/as434/powerpoint/fa08/early_dev.swfRequires the free flash player which can be downloaded from: www.adobe.comJost ExperimentsMesonephric Ducts(Wolffian Ducts)Mesonephric Ducts(Wolffian Ducts)Paramesonephric Ducts(Mullerian Ducts)TestisEpididymisEpididymisVas DeferensSeminal VesiclesOvaryOviductUterusSex Determination: The Jost ParadigmSex Determination: The Jost ParadigmChromosomal SexGonadal SexPhenotypic SexSex Determination: The Jost ParadigmSex Determination: The Jost ParadigmChromosomal SexGonadal SexPhenotypic SexChromosomal SexGonadal SexPhenotypic SexHormonal SexBrain and/or Behavioral SexChromosomal SexChromosomal Sex•Single Pair of sex chromosomes»mammals, some but not all vertebrates •Sex is environmentally determined»sea worms, fish, reptiles•Multiple sex chromosomes»invertebrates, insects, reptiles•Haplodiploidy»bees, spiders•Single Pair of sex chromosomes»mammals, some but not all vertebrates •Sex is environmentally determined»sea worms, fish, reptiles•Multiple sex chromosomes»invertebrates, insects, reptiles•Haplodiploidy»bees, spidersChromosomal SexChromosomal SexA. Drosophila•Sex depends on the number of X chromosomes–X or XY or XO = Male–XX or XXX or XXY = FemaleChromosomal SexChromosomal SexA. Drosophila•Sex depends on the number of X chromosomes–X or XY or XO = Male–XX or XXX or XXY = FemaleB. Human (mammals)•XY or XXY or XXYY or XXXY = Male (testis)•XX or XXX = Female (ovary)•XO = Female with incomplete ovarian development•XXY or XXYY or XXXY or XXXXY = testis but impaired sperm productionChromosomal SexChromosomal SexA. Drosophila•Sex depends on the number of X chromosomes–X or XY or XO = Male–XX or XXX or XXY = FemaleB. Human (mammals)•XY or XXY or XXYY or XXXY = Male (testis)•XX or XXX = Female (ovary)•XO = Female with incomplete ovarian development•XXY or XXYY or XXXY or XXXXY = testis but impaired sperm productionC. Conclusion•The gene that controls testicular differentiation is on the Y chromosome in mammals.Human X and Y ChromosomesYXThe Y ChromosomeThe Y ChromosomeA. Region coding for testicular development–H-Y Antigen«no longer believed to be involved–SRY«Codes for a DNA binding protein«acts as a transcription factor«Causes•primary sex chord (seminiferous tubule) development•Development of Sertoli Cells•Anti-Mullerian Hormone production by Sertoli Cells«absence of SRY •2nd sex chords (egg nests) develop•Short arm of Y chromosomeThe Y Chromosome Cont.B. Other genes on the Y chromosome»Spermatogenesis»androgen production »long bone growthSRY and Birds•Birds »females ZW, males ZZ»W chromosome determines sex»SRY is found on the Z chromosome !•SRY is not the only sex determining gene in animalsGonadal SexGonadal SexTestis Determining Factor(SRY gene product)XY MaleTestes developRete TubulesUndifferentiated Sex ChordsMullerian DuctMesonephric Duct(Wolffian Duct)Tunica AlbugineaMesonephric TubulesTesticular DevelopmentRete TubulesPrimary, Epithelial orMedullary Sex Chords•Primordial germ cells (gonocytes)•Pre-Sertoli CellsMullerian DuctWolffian DuctTunica AlbugineaMesonephric TubulesPrimary Sex Chords in Fetal TestisGonocyteGonocytePre-SertoliPre-SertoliHormonal SexHormonal SexTestis Determining Factor(SRY gene product)Testes developXY MaleSertoli cells secreteanti-mullerian hormone (AMH)AMH causes leydigcells to differentiateTestosteroneDevelopment of maleduct systemTestisTTNucleusTRWolffian Duct CellsRete TubulesSeminiferousTubulesVasDeferensTunica AlbugineaEfferent Ducts(Vas Efferentia)EpididymisTestis Determining Factor(SRY gene product)Testes developXY MaleSertoli cells secreteanti-mullerian hormone (AMH)AMH causes leydigcells to differentiateTestosteroneDevelopment of maleduct systemDegeneration of Mullerian ductVas efferentiaFemale DevelopmentXX FemaleNo TDFOvaries DevelopNo AMHMullerian ducts becomethe oviducts, uterus, cervix and part of the vaginaTestes Determining FactorNoTestosteroneWolffian DuctsRegressMullerianDuctPrimary or EpithelialSex ChordsWolffianDuctRegressingTubulesFuture OvarianCortexOvarian DevelopmentMullerianDuctRegressingEpithelialSex ChordsRegressingWolffianDuctRegressingTubulesFuture OvarianCortexMullerianDuctRegressingEpithelialSex ChordsRegressingWolffianDuctRegressingTubulesFuture OvarianCortexPrimordialFolliclesSecondary or Cortical Sex Chords(egg nests)MullerianDuctRegressingWolffianDuctOvarianCortexPrimordialFolliclesOvarianMedulla2nd Sex Chords in Fetal OvaryDevelopmentof the Uterus, Cervixand VaginaMullerian DuctMullerian DuctFused MullerianDuctHymenOvaryRegressingWolffian DuctMullerianDuctBroad Ligament Development(transverse anterior section)Reproductive tract develops outside theperitoneum!OvaryRegressingWolffianDuctMullerianDuctRegressingWolffianDuctMullerianDuctGenital Fold(Future Broad Ligament)(Posterior Transverse Section)Testis Determining Factor(SRY gene product)Testes developSertoli cells secreteanti-mullerian hormone (AMH)AMH causes leydigcells to differentiateDegeneration of Mullerian ductTestosteroneDevelopment of maleduct systemXY MaleNo TDFOvaries
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