Genetics of reproductive isolation and sex determination in allopolyploid clawed frogs (xenopus)

遗传学家感兴趣的是导致生殖不相容的基因的身份和影响。 另一个重要的分子遗传学问题是多倍体生物如何在完全基因组复制后保持关键的表型，如性别决定。 这项拟议中的研究将利用多倍体爪蛙（Xenopus）来调查与生殖不相容有关的基因的丰度和影响，并缩小决定其性别的遗传区域。 我们将利用这个小组的大量技术资源，包括完整的基因组序列，表达序列标签数据库和预制的微阵列芯片。 我们还将利用和探索使这些青蛙适合遗传调查的自然特征，包括生产可行的杂交种和回交，以及通过多倍化形成的旁系同源物的差异表达。 我们的具体目标是（a）使用表型关联映射，以进一步缩小爪蛙的性别决定区域，（B）量化的数量和影响的基因，导致物种之间的生殖不相容性，和（c）测试之间的相关性表达的分歧和回交杂种的生育力。 这项工作的结果将对我们理解基因和基因组复制产生影响-这是发生在整个生命树中的基本遗传过程，包括人类祖先。 本研究还将鉴定具有雄性偏好表达的基因，阐明物种间生殖不相容的遗传基础，并为研究基因组复制后的性别决定提供基因组框架。 这项工作将培养研究生和本科生在麦克马斯特在NSERC的优先领域，包括分子遗传学，功能基因组学，生物信息学和计算生物学。

Of interest to geneticists is the identity and impact of genes that cause reproductive incompatibilities. Another important molecular genetic question asks how polyploid organisms maintain crucial phenotypes, such as sex determination, in the wake of complete genome duplication. The proposed research will employ polyploid clawed frogs (Xenopus) to investigate the abundance and effect of genes involved with reproductive incompatibilities and also to narrow down the genetic region that determines their sex. We will utilize the considerable technical resources available for this group, including a complete genome sequence, expressed sequence tag databases, and prefabricated microarray chips. We will also utilize and explore natural characteristics that make these frogs amenable to genetic inquiry, including the production of viable hybrids and backcrosses, and differential expression of paralogs formed by polyploidization. Our specific goals are to (a) use phenotype association mapping to further narrow down the sex determining region of clawed frogs, (b) quantify the number and effect of genes that cause reproductive incompatibilities between species, and (c) test for a correlation between expression divergence and fertility of backcross hybrids. Results of this work will have implications for our understanding of gene and genome duplication - fundamental genetic processes that occurred throughout the tree of life including in human ancestors. This research will also identify genes with male-biased expression, elucidate the genetic basis of reproductive incompatibilities between species, and provide a genomic framework for study of sex determination after genome duplication. This work will train graduate and undergraduate students at McMaster in NSERC priority areas including molecular genetics, functional genomics, bioinformatics, and computational biology.