GENETICS AND EVOLUTION OF MORPHOLOGY IN DROSOPHILA

果蝇形态学的遗传学和进化

• 批准号: 2184700
• 负责人: CATHY C LAURIE
• 金额: $ 20.18万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-05-01 至 1996-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2184700
• 关键词: DNA; Drosophilidae; biochemical evolution; chromosome walking; developmental genetics; gene expression; gene mutation; genetic markers; genetic regulatory element; genetic transcription; male; molecular cloning; morphology; northern blottings; nucleic acid hybridization; nucleic acid sequence; reproductive development; sex differentiation; species difference; transposon /insertion element

The morphology of animal genitalia and associated structures that function in sperm transfer is often very complex and divergent among closely related species, particularly in insects. For example, Drosophila melanogaster has 7 sibling species, among which the only reliable morphological characters for identification are the male genitalia. Because these secondary sexual characteristics appear to be among the first characters to change in the evolution of new species, they provide a number of advantages for investigating the genetic and molecular basis of interspecific differences in morphology. The proposed project has 3 specific aims. (1) One aim is to determine the genetic architecture of the differences in male genitalia between D. mauritiana and D. simulans, which belong to the melanogaster subgroup of sibling species. The approach is to mark approximately 70 segments of the genome of one species with P-element insertions containing eye color marker. Each segment will be introgressed individually into the genome of the other species by repeated backcrossing for 26 generations and then made homozygous. Analysis of variation in genitalic characters among these lines will provide an estimate of the number of genes that affect these traits and the relative magnitude of those effects. In some cases, the importance of dominance and epistasis will also be investigated. (2) Genes of D. melanogaster that are involved in the development of the male genitalia will be identified by enhancer detector screening and P- element mutagenesis. Enhancer detector insertions that show a different pattern of expression in male and female genital discs potentially identify genes involved in producing the sexually dimorphic genitalia. This potential will be investigated by inducing mutations in nearby genes through imprecise excisions of the P-element. (3) When loss of function genitalic mutants are found, their possible role in causing interspecific differences will be investigated through a hybridization test. Any gene that appears to contribute substantially to these differences will be cloned and its molecular structure characterized. The molecular basis of these differences can then be investigated by interspecific gene transfer using P-element transformation. With this information, one can begin to answer long standing questions about the relative importance of structural and regulatory genetic changes in morphological evolution.

动物生殖器的形态和相关结构 精子移植中的功能通常非常复杂且多样化 密切相关的物种，特别是昆虫。 为了 例如，果蝇有 7 个兄弟物种，其中 用于鉴定的唯一可靠的形态特征是 男性生殖器。 因为这些第二性征 似乎是进化过程中最先发生变化的角色之一 新物种，它们提供了许多优势 研究种间遗传和分子基础 形态上的差异。 拟议项目有 3 个具体项目 目标。 (1) 目标之一是确定基因的遗传结构 D. mauritiana 和 D. mauritiana 之间男性生殖器的差异 simulans，属于同胞黑腹果蝇亚组 物种。 该方法是标记大约 70 个片段 含有眼睛的 P 元件插入物种的基因组 颜色标记。 每个片段将单独引入 通过重复回交 26 来获得其他物种的基因组 一代，然后成为纯合子。 变化分析 这些品系中的生殖特征将提供估计 影响这些性状的基因数量以及相对 这些影响的严重程度。 在某些情况下，重要性 还将研究显性和上位性。 (2)D基因 参与雄性发育的黑腹果蝇 生殖器将通过增强子检测器筛选和P-来识别 元素诱变。 增强检测器插入显示 男性和女性生殖盘的不同表达模式 潜在地识别参与产生性行为的基因 双形性生殖器。 这种潜力将由 通过不精确的切除来诱导附近基因的突变 P 元素。 (3) 当生殖器突变体丧失功能时 发现，它们在引起种间差异方面可能发挥作用 将通过杂交试验进行研究。 任何基因 似乎对这些差异有重大贡献 克隆并表征了其分子结构。 分子 然后可以通过以下方式调查这些差异的基础 使用 P 元件转化进行种间基因转移。 和 通过这一信息，人们可以开始回答长期存在的问题 关于结构和调控遗传的相对重要性 形态进化的变化。