Developmental defects of female-sterile mutants of Drosophila melanogaster

[摘要] Gansetal.(1975)isolatedfemale-sterilemutants,viableandnormalinthehomozygousstate,producingapparentlynormaleggswhichwereunabletodevelopordevelopedintodefectiveembryosoradults,evenwhenfertilizedwithwild-typesperm.Developmentalabnormalitiesofthesemutantsweresurveyedbyobservinglivingandfixedmaterial.Thefollowingtypesofmutantsweredistinguishedaccordingtothepredominantdevelopmentaldefect:(i)Eggsnotdevelopingatall,mostlyremainingunfertilized.(ii)Eggsstoppingdevelopmentafterafewcleavages,somewithpolyploidnuclei.(iii)Eggsstoppingdevelopmentatvariousembryonicstages,withhaploidnuclei.(iv)Eggswithabnormalblastoderm,notdevelopingfurtherorgivingabnormalembryos.(v)Eggswithabnormalgastrula,inonecasewithexcessiveinvaginations,inanothercasewithgermbandfailingtoelongate.(vi)Eggswithembryosdyingatdifferentstages,withouteasilyvisibleeffects.Severalofthemutantsweretemperaturesensitive.Inallthemutantstherewereeggsthatdiedwithoutdeveloping.Mostofthedevelopmentaldefectsappeartobeduetogeneralmetabolicdisturbancesoftheegg,notdirectlyrelatedtomorphogenesis.Therewerenomutantsaffectingdeterminationofaparticularadultorgan.Theclosesttoamorphologicaltypeofmutationwerethosewithabnormalblastodermhavingsuccessivebandsofnucleiofdifferentsizes.Thosemutantswerethermosensitive;atpermissivetermperaturestheydevelopedintoagameticadultsoradultswithvariousdefectsofabdomens,wingsoreyes.Thenatureofmaternalgeneticcontrolofearlymorphogensiswasdiscussed.

[学科分类] 生物科学（综合）