3.4 Genome Evolution and Estimation of Evolutionary Rate
To clarify M. japonicus genome evolution, 46,975 gene families
were clustered from 21 species. To reveal the phylogenetic relationships
among M. japonicus and other species, 174 single-copy ortholog
families derived from the 21 species were identified and the protein
sequences of these orthologs were aligned. The maximum-likelihood method
was used to performed phylogenetic analysis. According to the
phylogenetic analysis, M. japonicus might have started to diverge
from other species of shrimp approximately 119 million years ago (Figure
5).