Scanning electron microscopy of Drosophila melanogaster embryogenesis: II. Gastrulation and segmentation☆
[摘要] ThesequenceofgastrulationeventsinDrosophilamelanogaster,startingwiththecellularblastodermandculminatinginasegmentedembryo,havebeenstudiedwithscanningelectronmicroscopy(SEM).Extensiveuseismadeofdissectedembryostoillustratechangestakingplacewithintheembryoduringgastrulation.Duringthefirst15minofgastrulation,themesodermalportionofthegermbandisestablishedbytheinvaginationofapproximately1000cellsthroughtheventralfurrow.Theprimordiafortheproctodeumandhindgutareshowntoformduringearlygastrulation.Detailedexaminationofthesurfacesofinvaginatingprimordiashowssimilaritiestoothersystemsandsuggestspossibleunderlyingmechanisms.Germbandelongationandtheformationoftheamnioserosaaredescribed.Atthetimeofsegmentation,threepairsofrudimentarycephalicappendagesdevelopposteriortothecephalicfurrow.Trachealpitsinvaginateonalleightabdominalsegmentsandonthesecondandthirdthoracicsegments.Modificationsoftheembryonicfatemaparediscussed.
[发布日期] [发布机构]
[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
