Evidence map›Paper›PMID 32933484›Full record

ArticleBMC evolutionary biology2020

Similar patterns of genetic diversity and linkage disequilibrium in Western chimpanzees (Pan troglodytes verus) and humans indicate highly conserved mechanisms of MHC molecular evolution.

Christelle Vangenot, José Manuel Nunes, Gaby M Doxiadis, Estella S Poloni, Ronald E Bontrop, Natasja G de Groot, Alicia Sanchez-Mazas

Open access · goldAbstract read
In one paragraph

Article in BMC evolutionary biology, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
0.2field-weighted citation impact, top 51% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 5 citations in OpenAlex.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors at 2 institutions in 2 countries.

Christelle VangenotLaboratory of Anthropology, Genetics and Peopling History, Department of Genetics and Evolution, Anthropology Unit, University of Geneva, Geneva, Switzerland.
José Manuel NunesLaboratory of Anthropology, Genetics and Peopling History, Department of Genetics and Evolution, Anthropology Unit, University of Geneva, Geneva, Switzerland.
Gaby M DoxiadisComparative Genetics and Refinement, Biomedical Primate Research Centre, 2288, GJ, Rijswijk, The Netherlands.
Estella S PoloniLaboratory of Anthropology, Genetics and Peopling History, Department of Genetics and Evolution, Anthropology Unit, University of Geneva, Geneva, Switzerland.
Ronald E BontropComparative Genetics and Refinement, Biomedical Primate Research Centre, 2288, GJ, Rijswijk, The Netherlands.
Natasja G de GrootComparative Genetics and Refinement, Biomedical Primate Research Centre, 2288, GJ, Rijswijk, The Netherlands.
Alicia Sanchez-MazasLaboratory of Anthropology, Genetics and Peopling History, Department of Genetics and Evolution, Anthropology Unit, University of Geneva, Geneva, Switzerland. alicia.sanchez-mazas@unige.ch.ORCID 0000-0002-7714-2432
University of Geneva · CHBiomedical Primate Research Centre · NL

Funding

Fonds De La Recherche Scientifique - FNRS 310030_188820Fonds De La Recherche Scientifique - FNRS 320030_159669
6 · The paper itself

Abstract

backgroundMany species are threatened with extinction as their population sizes decrease with changing environments or face novel pathogenic threats. A reduction of genetic diversity at major histocompatibility complex (MHC) genes may have dramatic effects on populations' survival, as these genes play a key role in adaptive immunity. This might be the case for chimpanzees, the MHC genes of which reveal signatures of an ancient selective sweep likely due to a viral epidemic that reduced their population size a few million years ago. To better assess how this past event affected MHC variation in chimpanzees compared to humans, we analysed several indexes of genetic diversity and linkage disequilibrium across seven MHC genes on four cohorts of chimpanzees and we compared them to those estimated at orthologous HLA genes in a large set of human populations.

resultsInterestingly, the analyses uncovered similar patterns of both molecular diversity and linkage disequilibrium across the seven MHC genes in chimpanzees and humans. Indeed, in both species the greatest allelic richness and heterozygosity were found at loci A, B, C and DRB1, the greatest nucleotide diversity at loci DRB1, DQA1 and DQB1, and both significant global linkage disequilibrium and the greatest proportions of haplotypes in linkage disequilibrium were observed at pairs DQA1 ~ DQB1, DQA1 ~ DRB1, DQB1 ~ DRB1 and B ~ C. Our results also showed that, despite some differences among loci, the levels of genetic diversity and linkage disequilibrium observed in contemporary chimpanzees were globally similar to those estimated in small isolated human populations, in contrast to significant differences compared to large populations.

conclusionsWe conclude, first, that highly conserved mechanisms shaped the diversity of orthologous MHC genes in chimpanzees and humans. Furthermore, our findings support the hypothesis that an ancient demographic decline affecting the chimpanzee populations - like that ascribed to a viral epidemic - exerted a substantial effect on the molecular diversity of their MHC genes, albeit not more pronounced than that experienced by HLA genes in human populations that underwent rapid genetic drift during humans' peopling history. We thus propose a model where chimpanzees' MHC genes regenerated molecular variation through recombination/gene conversion and/or balancing selection after the selective sweep.

Indexed as

Evolution, MolecularGenetic VariationLinkage DisequilibriumPan troglodytesAllelesAnimalsGene FrequencyGenetics, PopulationHaplotypesHLA-D AntigensHominidaeHumansHLA-D AntigensBalancing selectionDemographic historyHLAHuman populationsLinkage disequilibriumMHCNucleotide diversityPatrPopulation bottleneckSelective sweepWestern chimpanzees

Identifiers

PMID32933484
PMCPMC7491122
OpenAlexW3087644802

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.