Molecular Genetic Studies of Bdelloid Rotifers

蛭形轮虫的分子遗传学研究

• 批准号: 9207199
• 负责人: Matthew Meselson
• 金额: $ 32.56万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-08-01 至 1996-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9207199&HistoricalAwards=false
• 关键词: Molecular; Genetic; Studies; Bdelloid; Rotifers

Bdelloid rotifers are common fresh-water invertebrates comprising 4 families, numerous genera and hundreds of species. Neither males nor meiosis are known within the Class. Although remarkable, this does not exclude rare or unrecognized forms of genetic exchange. A more rigorous test is therefor required. The proposed investigation depends on the expectation that a diploid line that lost sexual reproduction and genetic recombination far back in its evolution will accumulate a much higher level of silent-site heterozygosity than a sexually reproducing line. For a given gene, heterozygosity will be measured by comparing the nucleotide sequences of its two homologues cloned from the DNA of a rotifer population grown from a single egg. Such tests will be done with a number of different genes and different bdelloid families and genera. Bdelloid DNA will also be examined for mobile genetic elements, in order to test the possible association between sexual reproduction and the load of insertion mutations. For comparison, heterozygosity and mobile elements will also be investigated in monogononts, a class of rotifers in which sexual reproduction and meiosis are known. %%% The usual and accepted view is that without sex and recombination, evolution and adaptive success is not possible. That hypothesis, however, has been impossible to test. The availability of Bdelloid rotifers and recombinant DNA technology have changed that and this work may make it possible to find a more definitive answer to a fundamental question in genetics.

蛭形轮虫是常见的淡水无脊椎动物，包括 4科，众多属，数百种。 男性也没有 也没有减数分裂是已知的类。 虽然这很了不起， 并不排除罕见或未被识别的基因交换形式。 因此，需要进行更严格的测试。 拟议 研究依赖于期望一个二倍体系， 早在公元前就失去了有性生殖和基因重组 进化将积累更高水平的沉默位点 杂合性比有性繁殖线。 对于给定的基因， 杂合性将通过比较核苷酸 从轮虫DNA中克隆的两个同源物的序列 从一个鸡蛋中成长起来的种群。 这些测试将与 有许多不同的基因和不同的蛭形家族， 属 还将检查蛭形DNA中的移动的遗传 元素，以测试性别之间的可能联系， 繁殖和插入突变的负荷。 作为比较， 杂合性和移动的元件也将在 单殖体，一类轮虫，其中有性生殖和 减数分裂是已知的。 %%% 通常和公认的观点是，没有性别和重组， 进化和适应性的成功是不可能的。 这个假设， 然而，这是不可能测试的。 Bdelloid的可用性 轮虫和重组DNA技术改变了这一点， 工作可能会找到一个更明确的答案， 遗传学的基本问题。