Genetic Basis of Species Differences in Drosophila

描述（由申请人提供）：我们实验室的长期目标是 通过基因分析，了解产生新的 物种及其形态和行为的差异。这里我们 建议研究黑腹果蝇亚群中的两对物种， 一个包含最近发现的进化分歧D.桑托梅亚 新发现的岛屿特有种），和它的姐妹种D。Yakuba;另一个 独立的姐妹对D毛里求斯/拟杜父木我们提出以下要求 问题. 1.它们之间生殖隔离的形式和程度是什么？圣梅亚 和D.日式料理？我们将量化性，受精后，和“交配后， 前合子”隔离。这些研究对于我们的遗传分析是必要的， 这些特征，但也将使我们能够比较这种进化分歧， 在同一组中有两个独立的物种形成事件， 在同一时间 2.性隔离、杂种雄性不育和雄性不育的遗传基础是什么？ 这两个物种的色素有什么不同吗这些问题 将回答数量性状基因座（QTL）定位，一种方法更多 比我们过去使用的粗糙的基于mux的映射更精确。的 获得有关染色体数目、效应和位置的信息 影响物种形成和性格差异的区域将有助于回答 进化遗传学的长期问题。 3.“强化”在D中起作用吗？santomea/yakuba？这些物种有 在圣托姆岛上的重叠范围，使我们能够执行一个罕见的 测试“强化”：有争议的想法，自然选择可以 增加物种之间的性隔离程度， 重叠 4.性隔离的遗传基础是什么？simulans和D. 毛里求斯？几乎没有什么是已知的遗传性隔离， 这两个人的分歧也涉及岛屿殖民。QTL作图将 揭示了参与的染色体区域的数量，影响和位置， 性隔离的男性，女性，和缩短种间 交配抑制基因流动 我们的研究结果将使我们能够比较独立但 密切相关的类群，最终可能有助于定位和隔离 “物种形成”和“适应”基因，可能与理解 物种起源于其他动物群体，包括人类。

DESCRIPTION (provided by applicant): The long-term goal of our laboratory is to understand, through genetic analysis, the evolutionary forces producing new species and the attendant differences in their morphology and behavior. Here we propose to study two pair of species in the Drosophila melanogaster subgroup, one comprising a recently discovered evolutionary divergence D. santomea (a newly-found island endemic), and its sister species D. yakuba; and the other the independent sister pair D. mauritiana/D.simulans. We ask the following questions. 1. What are the forms and degrees of reproductive isolation between D. santomea and D. yakuba? We will quantify sexual, postzygotic, and "postmating, prezygotic" isolation. These studies are necessary for our genetic analysis of these traits, but will also allow us to compare this evolutionary divergence with two independent speciation events in the same group, all of which occurred at about the same time. 2. What are the genetic bases of sexual isolation, hybrid male sterility, and a striking difference in pigmentation between these two species? These questions will be answered with quantitative-trait-locus (QTL) mapping, a method more precise than the crude mutant-based mapping we have used in the past. The acquired information about the numbers, effects, and locations of chromosome regions affecting speciation and character differences will help answer long-standing questions of evolutionary genetics. 3. Does "reinforcement" operate in D. santomea/yakuba? These species have overlapping ranges on the island of Sao Tome, allowing us to perform a rare test for "reinforcement": the controversial idea that natural selection can increase the degree of sexual isolation between species in their area of overlap. 4. What is the genetic basis of sexual isolation between D. simulans and D. mauritiana? Almost nothing is known about the genetics of sexual isolation in this pair, whose divergence also involved island colonization. QTL mapping will reveal the numbers, effects, and locations of chromosomes regions involved in sexual isolation of males, of females, and of shortened interspecific copulation inhibiting gene flow. Our results will allow us to compare patterns of speciation in independent but closely related taxa, may eventually facilitate the location and isolation of "speciation" and "adaptation" genes, and may be relevant to understanding the origin of species in other animal groups, including humans.