Diversification of Self-incompatibility Alleles in the Rosaceae

蔷薇科自交不亲和等位基因的多样化

• 批准号: 0108173
• 负责人: Joshua Kohn
• 金额: $ 19.6万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-15 至 2005-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0108173&HistoricalAwards=false
• 关键词: Diversification; Self; incompatibility; Alleles; Rosaceae

Two distantly related plant families, the Solanaceae (potato family) and Rosaceae (rose family) use the same molecular method to reject self pollen. This project will examine diversification at the self incompatibility (S-) locus in the Rosaceae to test hypotheses about differences in S-allele evolution in the two families. Preliminary data indicate that alleles in the Rosaceae are quite young and that non-overlapping sets of alleles occur in the two subfamilies investigated. This stands in stark contrast to the lack of turnover and ancient alleles seen in the Solanaceae. This project will determine if these differences generally hold or are peculiar to the groups of Rosaceae that have been sampled and evaluate equilibrium and non-equilibrium hypotheses to explain family-level differences. This project will also use sequence and gene structure information to determine whether use RNases for self incompatibility in these two families is due to common ancestry or parallel evolution. Loci involved in self-nonself recognition exhibit the highest levels of genetic variability known. Examples include the self-incompatibility loci of flowering plants, fungi, and clonal marine invertebrates, and the disease fighting major histocompatiblity loci (MHC) of humans and other vertebrates. Extreme variability is due to the types of selection, generally called balancing selection, that act on such genes. Understanding the evolution these genes is important for many fields. First, the much greater time depth of variation allows historical inference that reaches farther back in time than is possible when using other genes. Second, analysis of diversification patterns at these genes provides information on the selective forces that drive their evolution. Third, examination of patterns of selection at the molecular level provides insight into as yet poorly understood aspects of the molecular basis of self recognition.

两个远距离相关的植物科，分子科（马铃薯家族）和酒渣鼻科（玫瑰家族）使用相同的分子方法来拒绝自花粉。该项目将在酒渣科中自我不兼容（S-）基因座的多元化检查，以测试两个家族中S-亚利氏进化差异的假设。初步数据表明，酒渣鼻的等位基因很年轻，并且在研究的两个亚家族中发生了不重叠的等位基因。这与缺乏离职率和在茄科中看到的古老等位基因形成鲜明对比。该项目将确定这些差异是否普遍存在或对已被采样并评估平衡和非平衡假设进行评估以解释家庭水平差异的均衡性差异。该项目还将使用序列和基因结构信息来确定在这两个家族中使用RNase是由于共同的血统或平行演化所致。参与自我识别的基因座表现出最高水平的遗传变异性。例子包括开花植物，真菌和克隆海洋无脊椎动物的自我兼容基因座，以及与人类和其他脊椎动物的主要组织辅助基因座（MHC）作斗争的疾病。极端变异性是由于选择的类型（通常称为平衡选择）对这种基因作用。了解这些基因对许多领域都很重要。首先，变化的时间深度更大，可以追溯到时间的历史推断比使用其他基因时的时间更远。 其次，对这些基因的多元化模式的分析提供了有关推动其进化的选择性力的信息。第三，对分子水平的选择模式的检查提供了对自我识别分子基础方面尚未了解的洞察力。