The evolutionary ecology of the major histocompatibility complex.

School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen AB24 2TZ, UK.
Heredity (Impact Factor: 3.8). 02/2006; 96(1):7-21. DOI: 10.1038/sj.hdy.6800724
Source: PubMed

ABSTRACT The major histocompatibility complex (MHC) has become a paradigm for how selection can act to maintain adaptively important genetic diversity in natural populations. Here, we review the contribution of studies on the MHC in non-model species to our understanding of how selection affects MHC diversity, emphasising how ecological and ethological processes influence the tempo and mode of evolution at the MHC, and conversely, how variability at the MHC affects individual fitness, population dynamics and viability. We focus on three main areas: the types of information that have been used to detect the action of selection on MHC genes; the relative contributions of parasite-mediated and sexual selection on the maintenance of MHC diversity; and possible future lines of research that may help resolve some of the unanswered issues associated with MHC evolution.

1 Bookmark
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The giant panda (Ailuropoda melanoleuca) is one of the most famous flagship species for conservation and its draft genome has recently been assembled. However, the transcriptome is not yet available. In this study, the blood transcriptomes of three pandas were characterized and about 160 million sequencing reads were generated using Illumina HiSeq 2000 paired-end sequencing technology. The assembly yielded 92,598 transcripts with an average length of 1626 bp and N50 length of 2842bp. Based on a sequence similarity search against non-redundant (nr) protein database, a total of 38,522 (41.6%) transcripts were annotated. Of these annotated transcripts, 25,142 and 8272 transcripts were assigned to gene ontology terms and clusters of orthologous group, respectively. A search against the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG) indicated that 9098 (9.83%) transcripts mapped to 324 KEGG pathways, and the best represented functional categories of pathways were signal transduction and immune system. We have also identified 23,460 microsatellites, 43,560 SNPs as well as 21,456 alternative splicing events in the assembly. Additionally, a total of 24,341 complete open reading frames (ORFs) were detected from the assembly where 1492 ORFs were found to be novel gene loci as these have not been annotated so far in any public database.This article is protected by copyright. All rights reserved.
    Molecular Ecology Resources 01/2015; · 7.43 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We review research on the ultimate and proximate origins of variation along the extraversion continuum. After describing the cost-benefit tradeoffs that may have maintained variation in extraversion over human evolution, we consider the evidence bearing on multiple distinct evolutionary hypotheses regarding the causal underpinnings of such variation. On the basis of the reviewed evidence, we argue that fluctuating selection on specific polymorphic genotypes is unlikely to explain the origins of individual differences in extraversion. Rather, adaptively patterned variation in extraversion is likely orchestrated primarily by facultative adaptations designed to calibrate behavioral strategies to cues available in ontogeny. For example, emerging research supports the hypothesis that extraversion may be ''reactively heritable'' by virtue of its calibration to heritable condition-dependent phenotypic features – which in turn helps explain extraversion's genetic variance, as well as its consistent positive association with reproductive success. Finally, evidence suggests that some of the inter-individual variance in extraversion is fundamentally noisy, arising as a side effect of mutation–selection balance or pleiotropic polymorphisms maintained via pathogen–host coevolution. If correct, these conclusions indicate that future research should focus on elucidating the facultative adaptations designed to regulate the production of behaviors falling on the extraversion continuum.
    Personality and Individual Differences 01/2015; · 1.86 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background It has been well-established, both by population genetics theory and direct observation in many organisms, that increased genetic diversity provides a survival advantage. However, given the limitations of both sample size and genome-wide metrics, this hypothesis has not been comprehensively tested in human populations. Moreover, the presence of numerous segregating small effect alleles that influence traits that directly impact health directly raises the question as to whether global measures of genomic variation are themselves associated with human health and disease.ResultsWe performed a meta-analysis of 17 cohorts followed prospectively, with a combined sample size of 46,716 individuals, including a total of 15,234 deaths. We find a significant association between increased heterozygosity and survival (P¿=¿0.03). We estimate that within a single population, every standard deviation of heterozygosity an individual has over the mean decreases that person¿s risk of death by 1.57%.Conclusions This effect was consistent between European and African ancestry cohorts, men and women, and major causes of death (cancer and cardiovascular disease), demonstrating the broad positive impact of genomic diversity on human survival.
    BMC genetics. 12/2014; 15(1):1274.

Full-text (2 Sources)

Available from
May 29, 2014