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GENETICS AND EVOLUTION OF MORPHOLOGY IN DROSOPHILA

果蝇形态学的遗传学和进化

基本信息

批准号：
2749899
负责人：
CATHY C LAURIE
金额：
$ 12.86万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1992
资助国家：
美国
起止时间：
1992-05-01 至 1999-01-31
项目状态：
已结题

项目摘要

DESCRIPTION: In a very productive previous award, the PI developed a medium resolution map (scale of approximately 20 cm) using QTLs to identify genetic factors affecting the shape and size of the male posterior lobe. The proposed research will further resolve this map to a scale of 5-10 cm in regions already known to contain a factor. A second goal is to use mutations within D. melanogaster that affect the morphology of the male posterior lobe and create hybrids to determine whether the wild- type alleles of those mutant genes contribute to species differences. Enhancer-detector P-element insertions that exhibit male-limited lacZ expression in the genital disc will be studied as candidate genes. A collection of homozygous viable inserts with sex-dimorphic expression is in hand. These will be screened for sexually dimorphic lethal inserts in those chromosomal regions already identified as containing QTLs in the interspecific analysis. The lab will conduct a mosaic screen for X-ray induced mutations on the third chromosome and affecting posterior lobe morphology. This chromosome exhibits the greatest density of genes affecting male genital morphology in interspecific crosses. Once a candidate gene has been identified within the species, it will be assessed in a hybrid test using a recessive loss-of- function mutation, crossing the mutant in mel to each of the 3 sister taxa and comparing the resultant male phenotypes with those produced by similar crosses with wild-type mel. Once a candidate gene has been clearly implicated in normal development of the posterior lobe and in hybrid male differences, it will be cloned and characterized in terms of its transcriptional organization, protein sequence, and pattern of expression. P- element mediated transfer of the gene from other species into D. melanogaster will provide a conclusive test of the role of the gene in male genital development. Chimeric gene constructs will be used to further partition the gene into functional regions responsible for its effects to address exactly what aspects of the sequence are causally involved in the morphological differences between species. The pleotrpic effects of the gene and functional regions on other aspects of hybrid morphologies will also be investigated. Eventually, this should provide information regarding the evolution of genes vis-a-vis the selective forces operating in nature.

描述：在之前的一个非常富有成效的奖项中，PI 开发了一种媒介使用 QTL 来识别遗传的分辨率图（比例尺约为 20 cm）影响男性后叶形状和大小的因素。这拟议的研究将进一步将该地图解析为 5-10 厘米的比例已知含有某种因子的区域。第二个目标是使用影响雄性形态的黑腹果蝇突变后叶并创建杂交体以确定野生型是否这些突变基因的等位基因导致物种差异。增强子检测器 P 元件插入表现出男性限制的 lacZ 生殖盘中的表达将作为候选基因进行研究。一个具有性别二态性表达的纯合可行插入片段的集合位于手。将在这些中筛选性别二态性致死插入物已鉴定出含有 QTL 的染色体区域种间分析。实验室将对X射线进行马赛克筛查诱导第三染色体突变并影响后叶形态学。该染色体表现出最大的基因密度影响种间杂交中雄性生殖器的形态。一旦候选基因在物种内被鉴定出来，它将被使用隐性功能丧失突变在混合测试中进行评估，将 mel 中的突变体与 3 个姐妹类群中的每一个进行杂交，并比较与相似杂交产生的雄性表型野生型梅尔。一旦候选基因明确与正常情况有关后叶的发育和杂交雄性的差异，这将是对其转录组织进行克隆和表征，蛋白质序列和表达模式。 P-元件介导的转移将其他物种的基因导入黑腹果蝇将提供该基因在男性生殖器发育中的作用的结论性测试。嵌合基因构建体将用于进一步将基因划分为负责其影响的功能区域到底解决了什么问题序列的各个方面都因果性地涉及形态学物种之间的差异。该基因的多效性和混合形态其他方面的功能区也将被调查了。最终，这应该提供有关基因的进化与自然界中运作的选择力的关系。