Mechanisms of Positive Selection on Gamete Recogntion Proteins

与男性生殖功能相关的蛋白质通常比其他蛋白质进化得快得多。在将卵子和精子直接释放到海水中的海洋无脊椎动物中，这些雄性蛋白质，以及它们卵中携带的雌性补体，决定了个体和物种是否可以杂交。众所周知，自然选择促进了这些雄性蛋白质在物种之间的分化；然而，导致这种选择的机制——特别是与功能相关的女性蛋白的作用——仍然未知。Hellberg博士将通过比较来自不同种类的海蜗牛Tegula的编码lysin及其卵载受体（VERL）的基因的DNA序列来评估精子蛋白lysin的选择机制。VERL包含约30个150个氨基酸的内部重复序列，但该蛋白的开始和结束的侧翼区域的序列尚不清楚。使用分子方法，PI将确定VERL的DNA序列信息。然后，他将在不同种类的Tegula中比较这些序列数据的模式。VERL的变异模式应该阐明导致配子识别蛋白快速变化的机制，从而拓宽我们对适应性分子变化的理解，特别是对新的、生殖隔离物种的进化。此外，VERL和lysin之间的共同进化可能为高特异性分子胶的设计提供见解（与VERL一样，它们通常由重复的分子序列组成）。

0075382HellbergProteins associated with male reproductive function typically evolve much faster than other proteins. In marine invertebrates that release their eggs and sperm directly into seawater, these male proteins, along with their egg-borne female complements, determine whether individuals and species can interbreed. Natural selection is known to promote the divergence of these male proteins between species; however, the mechanisms causing this selection--particularly the role of functionally related female proteins--remain unknown. Dr. Hellberg will evaluate proposed mechanisms for selection on the sperm protein lysin by comparing DNA sequences of the genes encoding lysin and its egg-borne receptor (VERL) from different species of the marine snail Tegula. VERL contains about 30 internal repeats of 150 amino acids, but sequences for flanking regions at the beginning and end of this protein are not known. Using molecular methods, the PI will determine DNA sequence information for VERL. He will then compare patterns of this sequence data among different species of Tegula. Patterns of VERL variation should illuminate mechanisms causing rapid change in gamete recognition proteins, in turn broadening our understanding of adaptive molecular change in general and the evolution of new, reproductively isolated species in particular. In addition, co-evolution between VERL and lysin may provide insights into the design of highly specific molecular glues (which like VERL are often composed of repeated molecular sequences).