Fernandez-Guerra Antonio, Aze Antoine, Morales Julia, Mulner-Lorillon Odile, Cosson Bertrand, Cormier Patrick, Bradham Cynthia, Adams Nikki, Robertson Anthony J, Marzluff William F, Coffman James A, Genevière Anne-Marie
Observatoire Océanologique de Banyuls-Laboratoire Arago, CNRS-UMR7628/UPMC, 66650 Banyuls-sur-Mer, France.
Dev Biol. 2006 Dec 1;300(1):238-51. doi: 10.1016/j.ydbio.2006.09.012. Epub 2006 Sep 14.
A search of the Strongylocentrotus purpuratus genome for genes associated with cell cycle control and DNA metabolism shows that the known repertoire of these genes is conserved in the sea urchin, although with fewer family members represented than in vertebrates, and with some cases of echinoderm-specific gene diversifications. For example, while homologues of the known cyclins are mostly encoded by single genes in S. purpuratus (unlike vertebrates, which have multiple isoforms), there are additional genes encoding novel cyclins of the B and K/L types. Almost all known cyclin-dependent kinases (CDKs) or CDK-like proteins have an orthologue in S. purpuratus; CDK3 is one exception, whereas CDK4 and 6 are represented by a single homologue, referred to as CDK4. While the complexity of the two families of mitotic kinases, Polo and Aurora, is close to that found in the nematode, the diversity of the NIMA-related kinases (NEK proteins) approaches that of vertebrates. Among the nine NEK proteins found in S. purpuratus, eight could be assigned orthologues in vertebrates, whereas the ninth is unique to sea urchins. Most known DNA replication, DNA repair and mitotic checkpoint genes are also present, as are homologues of the pRB (two) and p53 (one) tumor suppressors. Interestingly, the p21/p27 family of CDK inhibitors is represented by one homologue, whereas the INK4 and ARF families of tumor suppressors appear to be absent, suggesting that these evolved only in vertebrates. Our results suggest that, while the cell cycle control mechanisms known from other animals are generally conserved in sea urchin, parts of the machinery have diversified within the echinoderm lineage. The set of genes uncovered in this analysis of the S. purpuratus genome should enhance future research on cell cycle control and developmental regulation in this model.
对紫海胆基因组中与细胞周期调控和DNA代谢相关的基因进行搜索后发现，这些基因的已知种类在海胆中是保守的，尽管其家族成员数量比脊椎动物中少，并且存在一些棘皮动物特有的基因多样化情况。例如，已知细胞周期蛋白的同源物在紫海胆中大多由单个基因编码（与具有多种异构体的脊椎动物不同），但还有额外的基因编码B型和K/L型的新型细胞周期蛋白。几乎所有已知的细胞周期蛋白依赖性激酶（CDK）或CDK样蛋白在紫海胆中都有直系同源物；CDK3是个例外，而CDK4和6由一个单一的同源物代表，称为CDK4。虽然有丝分裂激酶的两个家族——Polo和Aurora的复杂性与线虫中的相近，但NIMA相关激酶（NEK蛋白）的多样性接近脊椎动物。在紫海胆中发现的9种NEK蛋白中，8种可以在脊椎动物中找到直系同源物，而第9种是海胆特有的。大多数已知的DNA复制、DNA修复和有丝分裂检查点基因也存在，还有pRB（两个）和p53（一个）肿瘤抑制因子的同源物。有趣的是，CDK抑制剂的p21/p27家族由一个同源物代表，而肿瘤抑制因子的INK4和ARF家族似乎不存在，这表明这些家族是在脊椎动物中才进化出来的。我们的结果表明，虽然其他动物中已知的细胞周期调控机制在海胆中总体上是保守的，但部分机制在棘皮动物谱系中已经多样化。在对紫海胆基因组的这一分析中发现的基因集应会加强对该模型中细胞周期调控和发育调节的未来研究。
