Variation and heritability of retinal cone ratios in a free-ranging population of rhesus macaques

Cayo Biobank Research Unit

    Research output: Contribution to journalArticlepeer-review


    A defining feature of catarrhine primates is uniform trichromacy—the ability to distinguish red (long; L), green (medium; M), and blue (short; S) wavelengths of light. Although the tuning of photoreceptors is conserved, the ratio of L:M cones in the retina is variable within and between species, with human cone ratios differing from other catarrhines. Yet, the sources and structure of variation in cone ratios are poorly understood, precluding a broader understanding of color vision variability. Here, we report a large-scale study of a pedigreed population of rhesus macaques (Macaca mulatta). We collected foveal RNA and analyzed opsin gene expression using cDNA and estimated additive genetic variance of cone ratios. The average L:M ratio and standard error was 1.03:1 ± 0.02. There was no age effect, and genetic contribution to variation was negligible. We found marginal sex effects with females having larger ratios than males. S cone ratios (0.143:1 ± 0.002) had significant genetic variance with a heritability estimate of 43% but did not differ between sexes or age groups. Our results contextualize the derived human condition of L-cone dominance and provide new information about the heritability of cone ratios and variation in primate color vision.

    Original languageEnglish (US)
    Pages (from-to)1776-1789
    Number of pages14
    Issue number8
    StatePublished - Aug 2022


    • Catarrhine
    • color vision
    • droplet digital PCR
    • gene expression
    • heritability
    • opsin

    ASJC Scopus subject areas

    • Ecology, Evolution, Behavior and Systematics
    • Genetics
    • General Agricultural and Biological Sciences


    Dive into the research topics of 'Variation and heritability of retinal cone ratios in a free-ranging population of rhesus macaques'. Together they form a unique fingerprint.

    Cite this