Cortical folding of the primate brain: An interdisciplinary examination of the genetic architecture, modularity, and evolvability of a significant neurological trait in pedigreed baboons (genus papio)

Elizabeth G. Atkinson, Jeffrey Rogers, Michael C. Mahaney, Laura A. Cox, James M. Cheverud

    Research output: Contribution to journalArticlepeer-review

    15 Scopus citations

    Abstract

    Folding of the primate brain cortex allows for improved neural processing power by increasing cortical surface area for the allocation of neurons. The arrangement of folds (sulci) and ridges (gyri) across the cerebral cortex is thought to reflect the underlying neural network. Gyrification, an adaptive trait with a unique evolutionary history, is affected by genetic factors different from those affecting brain volume. Using a large pedigreed population of ~1000 Papio baboons, we address critical questions about the genetic architecture of primate brain folding, the interplay between genetics, brain anatomy, development, patterns of cortical–cortical connectivity, and gyrification’s potential for future evolution. Through Mantel testing and cluster analyses, we find that the baboon cortex is quite evolvable, with high integration between the genotype and phenotype. We further find significantly similar partitioning of variation between cortical development, anatomy, and connectivity, supporting the predictions of tension-based models for sulcal development. We identify a significant, moderate degree of genetic control over variation in sulcal length, with gyrus-shape features being more susceptible to environmental effects. Finally, through QTL mapping, we identify novel chromosomal regions affecting variation in brain folding. The most significant QTL contain compelling candidate genes, including gene clusters associated with Williams and Down syndromes. The QTL distribution suggests a complex genetic architecture for gyrification with both polygeny and pleiotropy. Our results provide a solid preliminary characterization of the genetic basis of primate brain folding, a unique and biomedically relevant phenotype with significant implications in primate brain evolution.

    Original languageEnglish (US)
    Pages (from-to)651-665
    Number of pages15
    JournalGenetics
    Volume200
    Issue number2
    DOIs
    StatePublished - 2015

    Keywords

    • Cerebral cortex
    • Evolution
    • Gyrification
    • Heritability
    • Modularity
    • Papio hamadryas
    • Primate brain
    • Qtl

    ASJC Scopus subject areas

    • Genetics

    Fingerprint

    Dive into the research topics of 'Cortical folding of the primate brain: An interdisciplinary examination of the genetic architecture, modularity, and evolvability of a significant neurological trait in pedigreed baboons (genus papio)'. Together they form a unique fingerprint.

    Cite this