Center for Genomics and Bioinformatics, Indiana University, 915 East Third Street, Bloomington, IN 47405, USA.
Science. 2011 Feb 4;331(6017):555-61. doi: 10.1126/science.1197761.
We describe the draft genome of the microcrustacean Daphnia pulex, which is only 200 megabases and contains at least 30,907 genes. The high gene count is a consequence of an elevated rate of gene duplication resulting in tandem gene clusters. More than a third of Daphnia's genes have no detectable homologs in any other available proteome, and the most amplified gene families are specific to the Daphnia lineage. The coexpansion of gene families interacting within metabolic pathways suggests that the maintenance of duplicated genes is not random, and the analysis of gene expression under different environmental conditions reveals that numerous paralogs acquire divergent expression patterns soon after duplication. Daphnia-specific genes, including many additional loci within sequenced regions that are otherwise devoid of annotations, are the most responsive genes to ecological challenges.
我们描述了微小甲壳动物溞属（Daphnia pulex）的基因组草图，其长度仅为 2 亿个碱基对，却至少包含 30907 个基因。高基因数量是由于基因重复率升高导致串联基因簇所致。在任何其他可用蛋白质组中，三分之一以上的溞属基因都没有可检测到的同源物，而扩增最多的基因家族是特定于溞属谱系的。参与代谢途径相互作用的基因家族的共同扩张表明，维持重复基因不是随机的，对不同环境条件下的基因表达进行分析表明，许多直系同源基因在重复后很快就获得了不同的表达模式。溞属特有的基因，包括在测序区域内的许多其他位点，这些位点在其他方面没有注释，是对生态挑战最敏感的基因。
