An analysis of the embryonic defects in Punch mutants of Drosophila melanogaster.
An analysis of the embryonic defects in Punch mutants of Drosophila melanogaster.
复制标题
果蝇 Punch 突变体胚胎缺陷分析。
DOI：
10.1016/0012-1606(87)90401-5
复制
发表时间：
1987
影响因子：
2.7
通讯作者：
O'Donnell,JM
中科院分区：
文献类型：
--
作者：
Reynolds,ER;O'Donnell,JM
Punch （Pu）是一个复杂的遗传位点，编码GTP环水解酶，这是蝶啶生物合成途径中的第一个酶。在果蝇生命周期的幼虫和成虫阶段，基因座的功能可以通过酶测定来监测。虽然在幼虫期之前无法检测到酶活性，但由于大多数纯合突变体在胚胎发生期间死亡，因此该位点也必须具有早期功能。为了评估该基因座在这一发育阶段的作用，我们对不同种类的突变体胚胎进行了形态学检查。在变异的遗传类别和形态类别之间发现了精确的对应关系。基因座在胚胎发生的两个阶段是必需的。这些要求在基因上是可分离的，如每个时期具有特定缺陷的突变体所示。早期的功能利用母体和受精卵的成分。这些成分有缺陷的突变体具有异常的片段模式。在胚胎发生后期，apu产物对于幼虫角质层的正常色素沉着和其他结构的正确定位和分化是必需的，特别是在头部区域。由温度变化实验确定的冷敏感期对应于后一种功能。观察到的一些表型与已知的翼啶的生理作用相对应；还有一些是无法预料和解释的。
Punch (Pu), a complex genetic locus, encodes GTP cyclohydrolase, the first enzyme in the pteridine biosynthetic pathway. In the larval and adult stages of theDrosophilalife cycle, the function of the locus can be monitored by enzyme assays. Although enzyme activity cannot be detected prior to larval stages, the locus must also have earlier functions since most homozygousPumutants die during embryogenesis. In order to assess the role of the locus during this stage of development, morphological examinations of embryos from different classes ofPumutants were performed. An exact correspondence has been found between genetic and morphological classes ofPumutations. The locus is required during two periods of embryogenesis. These requirements are genetically separable as shown by mutants with defects specific to each period. An early function utilizes both maternal and zygotic components. Mutants defective for these components have abnormal segment patterns. Late in embryogenesis, aPuproduct is necessary for the proper pigmentation of larval cuticle and proper orientation and differentiation of other larval structures, particularly in the head region. A cold-sensitive period corresponds to this later function as determined by temperature-shift experiments. Some of the phenotypes observed correspond to known physiological roles of pteridines; others are unexpected and unexplained.