Mesocentrotus franciscanus Genome sequencing and assembly

Sea urchins are marine invertebrates of extreme diversity of life span. Red sea urchin S. franciscanus is among the longest living creatures of the Ocean. Its lifetime is estimated to exceed a century, while the green sea urchin L. variegatus hardly survive more than 3 years. We sequenced and compared the genomes of these animals aiming at determination of the genetic basis of their longevity difference. List of genes related to the longevity of other animal species was created and used for homology search among the genomic data obtained in this study. Aminoacid sequences of longevity related proteins of S. fransciscanus and L. variegatus as well as from a set of model species, were aligned and grouped on the basis of the species lifespan. Aminoacid residues specific for a longevity group were identified. Proteins containing aminoacids whose identity correlated with the lifespan were clustered on the basis of their function.海胆（sea urchin）是一类寿命跨度极具多样性的海洋无脊椎动物。其中，红海胆S. franciscanus是海洋中最长寿的生物类群之一，其寿命预计可突破百年；而绿海胆L. variegatus的寿命罕有超过3年者。本研究对这两种海胆的基因组进行测序与比对，旨在解析二者寿命差异的遗传基础。我们首先构建了其他动物物种中与长寿相关的基因列表，并将其用于本研究获取的基因组数据的同源性搜索。随后，针对S. fransciscanus、L. variegatus以及一组模式物种的长寿相关蛋白氨基酸序列，我们依据物种寿命进行比对并分组，鉴定出了与长寿类群特异性相关的氨基酸残基。最后，我们基于功能对氨基酸序列一致性与寿命存在相关性的蛋白质开展了聚类分析。