Starter Grant: Molecular Evolution of Luciferase in Cypridinid Ostracodes

Elizabeth Torres博士是加州州立大学洛杉矶分校的一名新教员，她正在研究介形虫科的小型海洋甲壳类动物发光的分子进化。虽然生物发光现在在许多生物群体中都是已知的，包括细菌、鞭毛动物、腔肠动物、环节动物、软体动物、萤火虫和甲壳类动物，但假设在所有这些群体中都是独立进化的。塞浦路斯人产生自己独特形式的荧光素酶和底物荧光素，这些分子负责生物发光。根据分子和形态学数据，最近对塞浦路斯科的系统发育分析表明，生物发光在该家族中只进化了一次（但在各种谱系中已经丢失或改变）。为了分析萤光素酶基因的突变变化模式，基于已知的希尔根多菲弧条（Vargula hilgendorfii）基因序列和预计的tsujii弧条（Vargula tsujii）克隆序列，构建了基因探针。这些可以用来调查基因核苷酸差异在许多塞浦路斯物种。有了在许多分类群中已知的几个这样的序列，人们也可以开始分析保守的基序和其他基因特征，以检验荧光素酶是从各种发光生物群体中的加氧酶进化而来的假设。

0002692Torres Dr. Elizabeth Torres, a new faculty member at California State University, Los Angeles, is studying the molecular evolution of bioluminescence in small marine crustaceans of the ostracode family Cypridinidae. Although bioluminescence is now known in numerous groups of organisms, including bacteria, dinoflagellates, coelenterates, annelids, molluscs, fireflies, and crustaceans, it is hypothesized to have evolved independently in all these groups. Cypridinids produce their own unique forms of the enzyme luciferase and the substrate luciferin, the molecules responsible for bioluminescence. Recent phylogenetic analyses of Cypridinidae, based on molecular and morphological data, suggest that bioluminescence evolved just once in the family (but has been lost or altered in various lineages). To analyze the pattern of mutational changes in the luciferase gene throughout the lineages of cypridinids, gene probes are being constructed, based on the known gene sequences from Vargula hilgendorfii and anticipated from clones in hand of Vargula tsujii. These can be used to survey gene-nucleotide differences across numerous cypridinid species. With several such sequences known across many taxa, one can also begin analyses of conserved motifs and other gene characteristics, to test the hypothesis that luciferases have evolved from oxygenase enzymes, in the various groups of bioluminescent organisms.