Genomes of Strongylocentrotus franciscanus and Lytechinus variegatus: are there any genomic explanations for the two order of magnitude difference in the lifespan of sea urchins?

Abstract

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 survives more than four 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. Amino acid 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. Amino acid residues specific for a longevity group were identified. Proteins containing amino acids whose identity correlated with the lifespan were clustered on the basis of their function.

Keywords: genome sequencing; genomics; longevity; sea urchin.

Figure 1

Sea urchins used in this study. (A) S. franciscanus (B) L. variegatus.

Figure 2

Number of proteins containing aminoacid positions that vary in agreement with longevity. Shown are numbers of analyzed proteins by category (light grey) and those that contained aminoacids that co-vary with longevity (dark grey).