Influence of Gene Size and Exon-Intron Structure on Patterns and Rates of Evolution in Drosophila

基因大小和外显子-内含子结构对果蝇进化模式和速率的影响

• 批准号: 0344209
• 负责人: Josep Comeron
• 金额: $ 38万
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-15 至 2008-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0344209&HistoricalAwards=false
• 关键词: Influence; Gene; Size; Exon; Intron

The genetic information of most genes that code for proteins in eukaryotes is not contiguous but split into segments called 'exons' and 'introns'. Exons correspond to sequences with information for the amino acids of the encoded protein while introns are intervening sequences between exons that do not carry information for protein sequence. The number of introns in a gene varies considerably not only among different genes but also when comparing homologous genes between species. Nevertheless, little is known about the causes for intron presence and the evolution of exon-intron structures. Theoretical models of natural selection forecast that, all else being equal, genes with introns might exhibit a selective advantage compared to genes without introns, which would explain the prevalence of introns in most genomes. In this project the PI will investigate this possibility by applying population genetics techniques, both experimental and theoretical. To this purpose, the PI will obtain information of nucleotide variability within species (i.e., polymorphism) and between species (i.e., divergence) in several species of Drosophila and will estimate the efficacy of natural selection's taking advantage of advantageous mutations and eliminating deleterious mutations in four groups of genes classified according to the size of the coding sequence and intron presence/absence. The results from the proposed work will be significant for the field of population genetics and it will give new insight into the forces involved in the evolution of introns and gene structures, and genome size and organization in eukaryotes.

大多数基因在真核生物中为蛋白质编码的基因的遗传信息不是连续的，而是分为称为“外显子”和“内含子”的段。外显子对应于带有编码蛋白质氨基酸的信息的序列，而内含子是外显子之间不携带蛋白质序列信息的外显子之间的序列。 一个基因中的内含子的数量不仅在不同基因之间，而且在比较物种之间的同源基因时也有很大差异。然而，关于内含子存在和外显子内结构的演变的原因知之甚少。自然选择的理论模型预测，与没有内含子的基因相比，带有内含子的所有其他基因可能具有选择性优势，这可以解释大多数基因组中内含子的普遍性。 在该项目中，PI将通过应用人群遗传学技术（包括实验性和理论）来调查这种可能性。 为此，PI将获取物种内部核苷酸变异性的信息（即多态性）以及几种果蝇种类的物种（即差异）之间的信息（即差异），并将估计自然选择的优势，利用有优势的突变的优势，并根据编码和INTRON SEMINES/INTRON SERINES/INTRON ANSON ANDON/INTRON ANDONS ANDONS/INSTORICES ANGENES/INSCONTICE ALDONISE突变的效果。拟议工作的结果对于人口遗传学领域将是重要的，它将对内含子和基因结构演变的力量以及真核生物的基因组大小和组织提供新的见解。