Ostrowski Stephen, Dierick Herman A, Bejsovec Amy
Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois 60208, USA.
Genetics. 2002 May;161(1):171-82. doi: 10.1093/genetics/161.1.171.
The embryonic cuticle of Drosophila melanogaster is deposited by the epidermal epithelium during stage 16 of development. This tough, waterproof layer is essential for maintaining the structural integrity of the larval body. We have characterized mutations in a set of genes required for proper deposition and/or morphogenesis of the cuticle. Zygotic disruption of any one of these genes results in embryonic lethality. Mutant embryos are hyperactive within the eggshell, resulting in a high proportion reversed within the eggshell (the "retroactive" phenotype), and all show poor cuticle integrity when embryos are mechanically devitellinized. This last property results in embryonic cuticle preparations that appear grossly inflated compared to wild-type cuticles (the "blimp" phenotype). We find that one of these genes, krotzkopf verkehrt (kkv), encodes the Drosophila chitin synthase enzyme and that a closely linked gene, knickkopf (knk), encodes a novel protein that shows genetic interaction with the Drosophila E-cadherin, shotgun. We also demonstrate that two other known mutants, grainy head (grh) and retroactive (rtv), show the blimp phenotype when devitellinized, and we describe a new mutation, called zeppelin (zep), that shows the blimp phenotype but does not produce defects in the head cuticle as the other mutations do.
黑腹果蝇的胚胎角质层在发育的第16阶段由表皮上皮细胞沉积。这一坚韧的防水层对于维持幼虫身体的结构完整性至关重要。我们已经鉴定了一组角质层正确沉积和/或形态发生所需基因的突变。这些基因中任何一个的合子破坏都会导致胚胎致死。突变胚胎在卵壳内活动过度，导致卵壳内有很大比例的胚胎反转（“追溯性”表型），并且当胚胎被机械去卵黄时，所有胚胎的角质层完整性都很差。与野生型角质层相比，这最后一个特性导致胚胎角质层制剂看起来严重膨胀（“飞艇”表型）。我们发现其中一个基因，krotzkopf verkehrt（kkv）编码果蝇几丁质合成酶，并且一个紧密连锁的基因，knickkopf（knk）编码一种与果蝇E-钙黏蛋白shotgun有遗传相互作用的新蛋白质。我们还证明，另外两个已知的突变体，颗粒头（grh）和追溯性（rtv），在去卵黄时表现出“飞艇”表型，并且我们描述了一个新的突变体，称为齐柏林飞艇（zep），它表现出“飞艇”表型，但不像其他突变体那样在头部角质层产生缺陷。
