Sidow A
Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Proc Natl Acad Sci U S A. 1992 Jun 1;89(11):5098-102. doi: 10.1073/pnas.89.11.5098.
Diversification of the Wnt genes, a family of powerful developmental regulator molecules, is inferred by molecular evolutionary analyses. Fifty-five recently determined partial sequences from a variety of vertebrates and invertebrates, together with 17 published sequences, mostly from the mouse and Drosophila melanogaster, are analyzed. Wnt-1 through -7 originated before the last common ancestor of arthropods and deuterostomes lived. Another round of gene duplication, involving Wnt-3, -5, -7, and -10, occurred after the echinoderm lineage arose, on the ancestral lineage of jawed vertebrates. Increased constraints were imposed on the Wnt genes when jawed vertebrates originated, as indicated by an overall 4-fold lower rate of amino acid replacements in jawed vertebrates compared with invertebrates and jawless vertebrates. The Wnt genes are thus inferred to have undergone a disproportionately high amount of structural and functional evolution in the relatively short time (approximately 100 million years) between the origin of the echinoderm lineage and the first diversification of jawed vertebrates. A model is presented for the relationship of functional diversification of developmental regulators and their rates of amino acid replacement.
分子进化分析推断，强大的发育调节分子家族Wnt基因存在多样化现象。对来自各种脊椎动物和无脊椎动物的55个最近确定的部分序列，以及17个已发表的序列（大多来自小鼠和黑腹果蝇）进行了分析。Wnt - 1至 - 7在节肢动物和后口动物的最后一个共同祖先出现之前就已产生。在棘皮动物谱系出现后，在有颌脊椎动物的祖先谱系上发生了另一轮基因复制，涉及Wnt - 3、 - 5、 - 7和 - 10。有颌脊椎动物起源时，Wnt基因受到了更强的限制，这表现为有颌脊椎动物氨基酸替换率总体上比无脊椎动物和无颌脊椎动物低4倍。因此可以推断，Wnt基因在棘皮动物谱系起源与有颌脊椎动物首次分化之间相对较短的时间内（约1亿年）经历了异常大量的结构和功能进化。本文提出了一个关于发育调节因子功能多样化与其氨基酸替换率之间关系的模型。
