Linked Life Data

8747297

Source:http://linkedlifedata.com/resource/pubmed/id/8747297

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1996-10-23
pubmed:abstractText
The major histocompatibility complex (Mhc) is a family of loci characterized by its relatively rapid evolutionary turnover, large genetic distances between genes, and long persistence of allelic lineages effected by balancing selection. These features render the Mhc highly suitable for answering questions concerning speciation and adaptive radiation. The aim of the present study was to use Mhc-DRB genes to make inferences about the founding population of the Platyrrhini. Three segments, each approximately 300 base pairs in length, of the platyrrhine DRB genes were amplified by the polymerase chain reaction and sequenced. The segments were derived from intron 2, exon 3, and exon 6 of DRB genes from different species of New World monkeys. The results of the study have revealed that on a phylogenetic tree, all of the tested platyrrhine genes appear to form a single cluster, while all catarrhine DRB genes form a distinct cluster, although the bootstrap values fail to provide statistically significant support for the separation of these two clades. This observation suggests that the multiple platyrrhine genes originated from a single ancestral gene after the divergence of the Platyrrhini and Catarrhini and thus contradicts the results of an earlier study in which some exon 2 DRB sequences appeared to predate the split of the two primate groups. The inconsistency in the DRB gene phylogeny can be explained by postulating convergent evolution for the peptide-binding region of the DRB exon 2 sequences. The phylogeny of the platyrrhine DRB genes (except for exon 2) is relatively "shallow"; the distances between genes are relatively short (in comparison to the catarrhine DRB genes), and there is a tendency for sequences of individual species to cluster together. The phylogeny of the platyrrhine DRB genes is consistent with the postulate that a small population founded the group and that there is an ongoing adaptive radiation from small, relatively isolated founding populations.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1055-7903
pubmed:author
pubmed:issnType
Print
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
408-19
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Mhc-DRB genes and the origin of New World monkeys.
pubmed:affiliation
Max-Planck-Institut für Biologie, Abteilung Immungenetik, Tübingen, Germany.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.