Cartilaginous fish class II genes reveal unprecedented old allelic lineages and confirm the late evolutionary emergence of DM.

ABSTRACT: Cartilaginous fish (chimaeras, rays and sharks) are the most basal extant jawed vertebrates with an adaptive immune system based on the Major Histocompatibility Complex (MHC). Despite being a key taxon in the evolution of vertebrate adaptive immunity, no comprehensive characterization of MHC class II genes has been undertaken for the group. We performed extensive bioinformatic searches on a taxonomically diverse dataset of transcriptomes and genomes of cartilaginous fish targeting MHC class II sequences. Class IIα and IIβ sequences were retrieved from all taxa analyzed and showed typical features of classical class II genes. Phylogenetic trees of the immunoglobulin superfamily domain showed two divergent and remarkably ancient lineages of class II genes in Selachians (sharks), originating

SUBMITTER: Almeida T 

PROVIDER: S-EPMC8010645 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature