Starter Grant: Molecular Evolution of Luciferase in Cypridinid Ostracodes

0002692托雷斯伊丽莎白托雷斯博士是洛杉矶加州州立大学的新教员，她正在研究介形虫科小型海洋甲壳动物生物发光的分子进化。虽然生物发光现在已知存在于许多生物群体中，包括细菌、腰鞭毛虫、腔肠动物、环节动物、软体动物、萤火虫和甲壳类动物，但据推测，所有这些群体都是独立进化的。Cypridinids产生它们自己独特形式的酶萤光素酶和底物荧光素，这些分子负责生物发光。最近的系统发育分析Cypridinidae，分子和形态学数据的基础上，表明，生物发光进化只有一次在家庭（但已丢失或改变在各种血统）。为了分析整个cypridinids谱系中荧光素酶基因突变变化的模式，正在构建基因探针，基于来自Vargula hilgendorfii的已知基因序列和预期来自手头Vargula tsujii的克隆。这些可以用来调查许多cypridinid物种的基因核苷酸差异。有了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基序和其他基因特征，以检验在各种生物发光生物中，辅酶A酶是从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.