ArticleBMC evolutionary biology2017
Genetic basis of brain size evolution in cetaceans: insights from adaptive evolution of seven primary microcephaly (MCPH) genes.
Article in BMC evolutionary biology, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers, 1 of them a synthesis that pooled it.
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Who cites it
7 citing papers in PubMed, 1 synthesis or guideline pooled it, 25 citations in OpenAlex.
- Pooled it
- Evolution of canonical circadian clock genes underlies unique sleep strategies of marine mammals for secondary aquatic adaptation.PLoS genetics · 2025Article
- Molecular Evolution of Tooth-Related Genes Provides New Insights into Dietary Adaptations of Mammals.Journal of molecular evolution · 2021Article
- Evolution of ASPM coding variation in apes and associations with brain structure in chimpanzees.Genes, brain, and behavior · 2019Article
- Insights into body size variation in cetaceans from the evolution of body-size-related genes.BMC evolutionary biology · 2019Article
- Brain evolution in Proboscidea (Mammalia, Afrotheria) across the Cenozoic.Scientific reports · 2019Article
- Counter-Balance Between Gli3 and miR-7 Is Required for Proper Morphogenesis and Size Control of the Mouse Brain.Frontiers in cellular neuroscience · 2018Article
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Authors and funding
8 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundCetacean brain size expansion is an enigmatic event in mammalian evolution, yet its genetic basis remains poorly explored. Here, all exons of the seven primary microcephaly (MCPH) genes that play key roles in size regulation during brain development were investigated in representative cetacean lineages.
resultsSequences of MCPH2-7 genes were intact in cetaceans but frameshift mutations and stop codons was identified in MCPH1. Extensive positive selection was identified in four of six intact MCPH genes: WDR62, CDK5RAP2, CEP152, and ASPM. Specially, positive selection at CDK5RAP2 and ASPM were examined along lineages of odontocetes with increased encephalization quotients (EQ) and mysticetes with reduced EQ but at WDR62 only found along odontocete lineages. Interestingly, a positive association between evolutionary rate (ω) and EQ was identified for CDK5RAP2 and ASPM. Furthermore, we tested the binding affinities between Calmodulin (CaM) and ASPM IQ motif in cetaceans because only CaM combined with IQ, can ASPM perform the function in determining brain size. Preliminary function assay showed binding affinities between CaM and IQ motif of the odontocetes with increased EQ was stronger than for the mysticetes with decreased EQ. In addition, evolution rate of ASPM and CDK5RAP2 were significantly related to mean group size (as one measure of social complexity).
conclusionsOur study investigated the genetic basis of cetacean brain size evolution. Significant positive selection was examined along lineages with both increased and decreased EQ at CDK5RAP2 and ASPM, which is well matched with cetacean complex brain size evolution. Evolutionary rate of CDK5RAP2 and ASPM were significantly related to EQ, suggesting that these two genes may have contributed to EQ expansion in cetaceans. This suggestion was further indicated by our preliminary function test that ASPM might be mainly linked to evolutionary increases in EQ. Most strikingly, our results suggested that cetaceans evolved large brains to manage complex social systems, consisting with the 'social brain hypothesis', as evolutionary rate of ASPM and CDK5RAP2 were significantly related to mean group size.
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