Dataset Information

The common marmoset: a new world primate species with limited Mhc class II variability.

ABSTRACT: The common marmoset (Callithrix jacchus) is a New World primate species that is highly susceptible to fatal infections caused by various strains of bacteria. We present here a first step in the molecular characterization of the common marmoset's Mhc class II genes by nucleotide sequence analysis of the polymorphic exon 2 segments. For this study, genetic material was obtained from animals bred in captivity as well as in the wild. The results demonstrate that the common marmoset has, like other primates, apparently functional Mhc-DR and -DQ regions, but the Mhc-DP region has been inactivated. At the -DR and -DQ loci, only a limited number of lineages were detected. On the basis of the number of alleles found, the -DQA and -B loci appear to be oligomorphic, whereas only a moderate degree of polymorphism was observed for two of three Mhc-DRB loci. The contact residues in the peptide-binding site of the Caja-DRB1*03 lineage members are highly conserved, whereas the -DRB*W16 lineage members show more divergence in that respect. The latter locus encodes five oligomorphic lineages whose members are not observed in any other primate species studied, suggesting rapid evolution, as illustrated by frequent exchange of polymorphic motifs. All common marmosets tested were found to share one monomorphic type of Caja-DRB*W12 allele probably encoded by a separate locus. Common marmosets apparently lack haplotype polymorphism because the number of Caja-DRB loci present per haplotype appears to be constant. Despite this, however, an unexpectedly high number of allelic combinations are observed at the haplotypic level, suggesting that Caja-DRB alleles are exchanged frequently between chromosomes by recombination, promoting an optimal distribution of limited Mhc polymorphisms among individuals of a given population. This peculiar genetic make up, in combination with the limited variability of the major histocompatability complex class II repertoire, may contribute to the common marmoset's susceptibility to particular bacterial infections.

SUBMITTER: Antunes SG

PROVIDER: S-EPMC21711 | biostudies-literature | 1998 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The common marmoset: a new world primate species with limited Mhc class II variability.

Antunes S G SG de Groot N G NG Brok H H Doxiadis G G Menezes A A AA Otting N N Bontrop R E RE

Proceedings of the National Academy of Sciences of the United States of America 19980901 20

The common marmoset (Callithrix jacchus) is a New World primate species that is highly susceptible to fatal infections caused by various strains of bacteria. We present here a first step in the molecular characterization of the common marmoset's Mhc class II genes by nucleotide sequence analysis of the polymorphic exon 2 segments. For this study, genetic material was obtained from animals bred in captivity as well as in the wild. The results demonstrate that the common marmoset has, like other p ...[more]

PMID: 9751736

Similar Datasets

Project description:The study describes >400 major histocompatibility complex (MHC) class II B exon 2 and 114 intron 2 sequences of 36 passerine bird species, 13 of which belong to the group of Darwin's finches (DFs) and the remaining 23 to close or more distant relatives of DFs in Central and South America. The data set is analyzed by a combination of judiciously selected statistical methods. The analysis reveals that reliable information concerning MHC organization, including the assignment of sequences to loci, and evolution, as well as the process of species divergence, can be obtained in the absence of genomic sequence data, if the analysis is taken several steps beyond the standard phylogenetic tree construction approach. The main findings of the present study are these: The MHC class II B region of the passerine birds is as elaborate in its organization, divergence, and genetic diversity as the MHC of the eutherian mammals, specifically the primates. Hence, the reported simplicity of the fowl MHC is an oddity. With the help of appropriate markers, the divergence of the MHC genes can be traced deep in the phylogeny of the bird taxa. Transspecies polymorphism is rampant at many of the bird MHC loci. In this respect, the DFs behave as if they were a single, genetically undifferentiated population. There is thus far no indication of alleles that could be considered species, genus, or even DF group specific. The implication of these findings is that DFs are in the midst of adaptive radiations, in which morphological differentiation into species is running ahead of genetic differentiation in genetic systems such as the MHC or the mitochondrial DNA. The radiations are so young that there has not been enough time to sort out polymorphisms at most of the loci among the morphologically differentiating species. These findings parallel those on Lake Victoria haplochromine fishes. Several of the DF MHC allelic lineages can be traced back to the MHC genes of the species Tiaris obscura, which we identified previously as the closest extant relative of DFs in continental America.

Dataset Information

The common marmoset: a new world primate species with limited Mhc class II variability.

Publications

The common marmoset: a new world primate species with limited Mhc class II variability.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets