Evolution of a New Gene and Speciation

描述(由申请人提供)： 总的目标是通过分析最近复制的与杂交雄性不育有关的基因来了解物种分化的分子基础。该物种形成基因ods(Odyseus)是在果蝇进化过程中从神经元表达基因unc4复制而来的。Unc4似乎保留了祖先的功能，而ods则专门发挥了生精作用。有了这种专门化，消耗臭氧层物质显然已经迅速分化，而且这种迅速的分化已经使物种之间在形成杂交时不相容(Ting等人。1998年)。具体的目标是回答这些问题：1.ODS序列和表达的进化：我们将比较DNA序列和表达模式，两者都在迅速进化，在果蝇物种中。2.消耗臭氧层物质正常功能的进化：为了了解消耗臭氧层物质的分化，我们采用了一种新的同源依赖的DNA插入方法(Rong And Golic 2000)，将黑腹隐翅虫的0ds基因替换为毛滴虫和拟南虎的0ds基因。将分析由于更换而引起的表型和健康变化。3.0ds：0ds诱导的杂交不育的“异常”功能的进化被认为是“异常”功能。通过转基因实验，我们将解决ODS使杂交雄性不育的遗传机制。

DESCRIPTION (provided by applicant): The general goal is to understand the molecular basis of species differentiation by analyzing a recently duplicated gene, which is involved in hybrid male sterility. This speciation gene, Ods (Odysseus), was duplicated from the neuron-expressing gene, Unc4, during the evolution of Drosophila. Unc4 appears to retain the ancestral functions while Ods became specialized in a spermatogenic role. With this specialization, Ods has apparently diverged rapidly and such rapid divergence has made 0ds incompatible between species when hybrids are formed (Ting et al. 1998). The specific goal is to answer these questions: 1. Evolution of Ods sequence and expression: We will compare DNA sequences and expression patterns, both evolving rapidly, across Drosophila species. 2. Evolution of the normal functions of Ods: In order to understand Ods differentiation, we will use the new method of homology-dependent DNA insertion (Rong and Golic 2000) to replace the 0ds gene in D. melanogaster with those of D. mauritiana and D. simulans. Phenotypic and fitness changes due to the replacement will be assayed. 3. Evolution of the "abnormal" function of 0ds: 0ds-induced hybrid sterility is considered the "abnormal" function. By transgenic experiments, we will address the genetic mechanism by which 0ds sterilizes hybrid males.