Requirements for zygotic gene activity during gastrulation in Drosophila melanogaster.
Requirements for zygotic gene activity during gastrulation in Drosophila melanogaster.
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果蝇原肠胚形成过程中合子基因活性的要求。
DOI：
10.1016/0012-1606(85)90490-7
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发表时间：
1985
影响因子：
2.7
通讯作者：
Wieschaus,EF
中科院分区：
文献类型：
--
作者：
Zusman,SB;Wieschaus,EF
果蝇的折叠原肠胚形成（fog）和扭曲原肠胚形成（tsg）基因座的突变干扰了果蝇的早期形态发生运动。雾胚不形成正常的后中肠，尽管它们的胚带确实伸长，但它们不向背侧延伸。因此，当正常胚胎有完全延伸的胚带时，突变胚胎的胚带折叠到胚胎腹侧的内部。tsg胚胎在早期原肠胚形成期间有异常深的背褶，这与背细胞无法横向滑动为扩展的胚带让路有关。fog和tsg胚胎继续发育，但形成无组织的一龄幼虫。fog和tsg是合子活性基因，至少在原肠胚形成开始后10和20分钟表达。这两种突变在纯合生殖细胞中是可行的，并且野生型基因不需要在卵子发生期间表达以使杂合后代存活。然而，从母体生殖细胞中消除ofog+基因产物确实会影响在活杂合子原肠胚形成期间观察到的折叠程度。对雌成虫和幼虫雌雄同形体的分析表明，正常折叠的原肠胚形成基因的功能只在胚胎的后部区域需要，最可能的是在产生后部中肠或直肠的细胞中。嵌合体的相对存活率表明，具有嵌合体“致死灶”的胚胎在胚胎发生过程中也会死亡，尽管典型的fog表型仅在整个病灶突变时产生。与fogfocus相反，没有特定的细胞必须是野生型嵌合体才能生存。然而，胚胎背侧的野生型细胞在拯救胚胎方面最有效。这表明正常的tsg基因产物可能只在胚胎的背侧需要，可能在产生羊膜浆膜的区域。
Mutations at thefolded gastrulation (fog)andtwisted gastrulation (tsg)loci interfere with early morphogenetic movements inDrosophila melanogaster. fogembryos do not form a normal posterior midgut and although their germbands do elongate, they do not extend dorsally. As a result, when normal embryos have fully extended germbands, the germbands in mutant embryos are folded into the interior on the ventral side of the embryo.tsgembryos have abnormally deep dorsal folds during early gastrulation, associated with the failure of dorsal cells to slip laterally to make way for the expanding germband. Bothfogandtsgembryos continue to develop, but form disorganized first instar larvae.fogandtsgare zygotically active genes expressed at least by 10 and 20 min after the onset of gastrulation. Both mutations are viable in homozygous germ cells and the wild-type genes need not be expressed during oogenesis for survival of heterozygous progeny. Elimination offog+gene product from maternal germ cells does, however, affect the extent of folding observed during gastrulation in viable heterozygotes. Analysis offogadult and larval gynandromorphs indicates that normalfolded gastrulationgene function is only required at the posterior region of the embryo, most probably in the cells giving rise to the posterior midgut or proctodeum. The relative survival offogmosaics suggests that embryos with mosaic “lethal foci” also die during embryogenesis, although the typicalfogphenotype is only produced when the entire focus is mutant. In contrast to thefogfocus, no particular cell must be wild type intsgmosaics for survival. Wild-type cells on the dorsal side of the embryo, however, are most effective in rescuing the embryo. This indicates that normaltsggene product may be required only on the dorsal side of the embryo, potentially in the region which gives rise to the amnion serosa.