Transcriptional and genic basis of incipient speciation

描述（由申请人提供）：我们的总体目标是了解在物种形成的早期阶段表型分化的遗传和转录基础。我们将研究黑腹果蝇Z（津巴布韦）和M（世界性）行为小种之间交配行为的差异（Wu et al. 1995; Hollocher et al. 1997 a，B; Ting et al. 2001）。目的1 -在基因型水平上，我们将确定在表达基因的全基因组扫描中Z和M种族之间强烈分化的核苷酸位点。这些种族分化位点将锚转录和表型分化的遗传作图。我们将构建染色体3之间的Z-和M-种族的多重重组（MR）线这样的映射。目的2 -在转录水平上，我们将研究MR系的表达谱（在两种性别的头部和生殖器官中），并将这些谱与其潜在的基因型相关联。转录调控在联系表型和基因型方面是重要的。目的3 -在表型水平，我们将首先尝试找到表型分歧（行为隔离）的转录基础，使用MR线。我们还将把表型分歧与基因型变化直接联系起来。我们希望能够鉴定出一些候选的物种形成基因，并进行精确的基因替换（Rong and Golic 2000; Greenberg et al. 2003），以证实它们对交配行为的影响。

DESCRIPTION (provided by applicant): Our general goal is to understand the genetic and transcriptional bases of phenotypic divergence at an early stage of speciation. We shall study the divergence in mating behaviors between the Z (for Zimbabwe) and M (cosmopolitan) behavioral races of Orosophila melanogaster (Wu et al. 1995; Hollocher et al. 1997a, b; Ting et al. 2001). Aim 1 - At the genotypic level, we will identify nucleotide sites that are strongly differentiated between the Z and M races in a whole-genome scan of expressed genes. These race-differentiating sites will anchor genetic mapping of transcription and phenotypic divergence. We will construct multiply recombined (MR) lines for Chromosome 3 between the Z- and M-races for such mapping. Aim 2 - At the transcriptional level, we shall study the expression profiles of the MR lines (in heads and reproductive organs of the 2 sexes) and correlate these profiles with their underlying genotypes. The regulation of transcription is important in linking phenotype and genotype. Aim 3 - At the phenotypic level, we shall first attempt to find the transcriptional basis of the phenotypic divergence (behavioral isolation), using the MR lines. We shall also link phenotypic divergence to genotypic changes directly. We expect to identify a number of candidate "speciation genes,* and will carry out precise gene replacement (Rong and Golic 2000; Greenberg et al. 2003) to confirm their effects on the mating behavior.