Biermann C H
Department of Ecology and Evolution, State University of New York at Stony Brook, USA.
Mol Biol Evol. 1998 Dec;15(12):1761-71. doi: 10.1093/oxfordjournals.molbev.a025902.
The acrosomal protein bindin attaches sperm to eggs during sea urchin fertilization. Complementary to ongoing functional biochemical studies, I take a comparative approach to explore the molecular evolution of bindin in a group of closely related free-spawning echinoid species. Two alleles of the mature bindin gene were sequenced for each of six species in the sea urchin family Strongylocentrotidae. The nucleotide sequences diverged by at least 1% per Myr at both silent and replacement sites. Two short sections flanking the conserved block show an excess of nonsynonymous substitutions. Each is homologous to a region that had been identified as a target of selection in other sea urchin comparisons. A large proportion of the bindin-coding sequence consists of a highly variable repeat region. Bindin sequences, even including the large intron, could not resolve the branching order among five of the species.
在海胆受精过程中，顶体蛋白结合素将精子附着于卵子上。作为对正在进行的功能性生化研究的补充，我采用比较方法来探究一组亲缘关系密切的自由产卵海胆类物种中结合素的分子进化。对海胆科中六个物种的每个成熟结合素基因的两个等位基因进行了测序。在沉默位点和置换位点，核苷酸序列每百万年至少 diverged by 1%。保守区域两侧的两个短片段显示出非同义替换过量。每个片段都与在其他海胆比较中被确定为选择靶点的区域同源。结合素编码序列的很大一部分由高度可变的重复区域组成。结合素序列，即使包括大的内含子，也无法解析五个物种之间的分支顺序。 （注：“diverged by”此处翻译为“差异为”，因原文未明确给出准确释义，根据语境推测，若有更准确释义可替换使译文更准确）
