Linked Life Data

12140744

Source:http://linkedlifedata.com/resource/pubmed/id/12140744

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2002-7-25
pubmed:abstractText
In plants, fungi and marine invertebrates, there are genetic compatibility systems to ensure diversity in the offspring. The importance of genetic compatibility in gametic union and selective abortion in vertebrate animals has also been appreciated recently. There have been suggestions that the major histocompatibility complex (HLA in humans) may be a compatibility system in vertebrates. HLA class II haplotypes often contain a second expressed DRB locus which can be either DRB3, DRB4 or DRB5. These encode the supertypical specificities and mark the ancestral lineages. The members of each lineage have related DNA sequences at the main class II locus HLA-DRB1. We analysed 415 newborns at all expressed DRB loci by PCR analysis to seek evidence for sex-specific prenatal selection events. While there was no significant change in heterozygosity rates between males and females at DRB1, the proportion of males carrying two DRB1 specificities from different ancestral lineages was significantly increased (53.7% in males vs 39.3% in females, P = 0.003). The genotypes consisting of phylogenetically most distinct ones, namely the DRB3 and DRB4 haplotypes, showed the most striking difference between sexes (P = 0.007). These results suggested a more favourable outcome for male concepti heterozygous for supertypical haplotypes. Heterozygosity for most divergent haplotypical families ensures the highest degree of functional heterozygosity at the main HLA class II locus DRB1 while increasing the likelihood of heterozygosity also at other MHC loci. Our observations agree with the previously reported heterozygote excess in male newborn rats and mice. Correlations between MHC class II heterozygosity and advertised male quality in deer and pheasant as well as increased reproductive success in MHC class II heterozygous male macaques are examples of postnatal benefits of heterozygosity in males that may be behind the development of prenatal selection mechanisms. The MHC-mediated prenatal selection of males may also be one of the selective events suggested by the very high primary (male-to-female) sex ratio at fertilization reaching close to unity at birth in humans. These results provide an appealing working hypothesis for further studies in humans and other vertebrates.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1466-4879
pubmed:author
pubmed:issnType
Print
pubmed:volume
3
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
263-9
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:12140744-Alleles, pubmed-meshheading:12140744-Animals, pubmed-meshheading:12140744-Female, pubmed-meshheading:12140744-Gene Frequency, pubmed-meshheading:12140744-Genes, MHC Class II, pubmed-meshheading:12140744-Genotype, pubmed-meshheading:12140744-HLA-DR Antigens, pubmed-meshheading:12140744-HLA-DRB1 Chains, pubmed-meshheading:12140744-HLA-DRB3 Chains, pubmed-meshheading:12140744-HLA-DRB4 Chains, pubmed-meshheading:12140744-HLA-DRB5 Chains, pubmed-meshheading:12140744-Haplotypes, pubmed-meshheading:12140744-Heterozygote, pubmed-meshheading:12140744-Histocompatibility Testing, pubmed-meshheading:12140744-Humans, pubmed-meshheading:12140744-Infant, Newborn, pubmed-meshheading:12140744-Male, pubmed-meshheading:12140744-Polymerase Chain Reaction, pubmed-meshheading:12140744-Sex Characteristics
pubmed:year
2002
pubmed:articleTitle
Increased heterozygosity for MHC class II lineages in newborn males.
pubmed:affiliation
Department of Haematology, University of Wales College of Medicine, Cardiff CF14 4XN, UK. dorak@openlink.org
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't