Meeting Abstract

S1.10  Monday, Jan. 4  \’Post-2R\’ cyclostomes: a molecular phylogenetic view of the vertebrate ancestor KURAKU, S; University of Konstanz shigehiro.kuraku@uni-konstanz.de

Whole genome sequencing and elaborate comparative analyses for early chordates and jawed vertebrates (gnathostomes) have revealed highly conserved gene repertoires between these distant lineages and their expansion in the vertebrate lineage through the so-called two-round (2R) genome duplications. Undoubtedly, this has contributed to a basis of comparative analyses in functional aspects of the invertebrate-vertebrate transition, e.g. in Evo-Devo. This line of progress has also been awaited for cyclostomes (hagfishes and lampreys). However, amount of available sequence resources for cyclostomes and effort to characterize them remains insufficient. Importantly, there are quite a few difficult factors unique to this challenge in their phylogenetic position, basic genomic properties, and patterns in gene family evolution. To fill the invertebrate-gnathostome gap, insights into cyclostome genomics will be discussed by introducing original data supporting the recently proposed ‘post-2R cyclostomes’ hypothesis and evidence of lineage-specific gene losses and duplications in some regulatory genes.