Dissertation Research: Gene Leakage into a Hybridogenetic Fish of the Genus Poeciliopsis

论文研究：基因渗漏到拟青鱼属杂交鱼中

基本信息

批准号：
9902224
负责人：
Robert Vrijenhoek
金额：
$ 0.76万
依托单位：
Rutgers University New Brunswick
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
1999
资助国家：
美国
起止时间：
1999-06-01 至 2001-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9902224&HistoricalAwards=false
关键词：
Dissertation Research Gene Leakage into

项目摘要

9902224VrijenhoekAsexually reproducing species (clones) are considered evolutionary dead-ends due to an irreversible accumulation of slightly deleterious mutations (mutational meltdown). Despite this expectation, some asexual organisms are widespread and abundant. Several mechanisms are believed to retard mutational accumulation in an asexual lineage. One mechanism is to occasionally mate with a related sexual species and incorporate new gene copies that mask or replace mutational defects. The proposed studies will examine evidence for gene replacements in asexual lineages of topminnow fishes (genus Poeciliopsis). Genetic markers (protein and DNA sequences) will be examined to clarify the origin of the asexual lineage, and establish whether its genome contains novel genes from a related sexual species.Now that cloning of mammals is no longer a fantasy, scientists must look to natural models to assess the long- and short-term risks of asexual reproduction. Fish of the genus Poeciliopsis are among the most extensively studied organisms with closely related sexual and asexual forms. The proposed project builds on a 40-year history of genetic, ecological, and evolutionary studies with these fish. This study will provide insights on mechanisms that some asexual species use to circumvent mutational meltdown and avoid extinction.

9902224Vrijenhoek 无性繁殖物种（克隆）由于轻微有害突变（突变崩溃）的不可逆积累而被认为是进化的死胡同。尽管有这样的期望，一些无性生物仍然广泛且丰富。据信有几种机制可以延缓无性谱系中突变的积累。一种机制是偶尔与相关的有性物种交配，并整合新的基因拷贝来掩盖或取代突变缺陷。拟议的研究将检验顶级鲦鱼（Poeciliopsis 属）无性谱系中基因替代的证据。将检查遗传标记（蛋白质和 DNA 序列），以阐明无性谱系的起源，并确定其基因组是否包含来自相关有性物种的新基因。既然克隆哺乳动物不再是幻想，科学家必须寻求自然评估无性繁殖的长期和短期风险的模型。拟丽鱼属的鱼类是研究最广泛的生物之一，其有性和无性形式密切相关。拟议的项目建立在对这些鱼类进行 40 年遗传、生态和进化研究的历史基础上。这项研究将为一些无性繁殖物种用来规避突变崩溃和避免灭绝的机制提供见解。