High germline mutation rates, but not extreme population outbreaks, influence genetic diversity in a keystone coral predator

by Iva Popovic, Lucie A. Bergeron, Yves-Marie Bozec, Ann-Marie Waldvogel, Samantha M. Howitt, Katarina Damjanovic, Frances Patel, Maria G. Cabrera, Gert W örheide, Sven Uthicke, Cynthia Riginos Lewontin ’s paradox, the observation that levels of genetic diversity (π) do not scale linearly with census population size (Nc) variation, is an evolutionary conundrum. The most extreme mismatches between π andNc are found for highly abundant marine invertebrates. Yet, the influences of new mutations on π relative to extrinsic processes such asNc fluctuations are unknown. Here, we provide the first germline mutation rate (μ) estimate for a marine invertebrate in corallivorous crown-of-thorns sea stars (Acanthaster cf.solaris). We use high-coverage whole-genome sequencing of 14 parent-offspring trios alongside empirical estimates ofNc in Australia ’s Great Barrier Reef to jointly examine the determinants of π in populations undergoing extremeNc fluctuations. TheA. cf.solaris meanμ was 9.13 x 10−09 mutations per-site per-generation (95% CI: 6.51 x 10−09 to 1.18 x 10−08), exceeding estimates for other invertebrates and showing greater concordance with vertebrate mutation rates. Lower-than-expectedNe (~70,000 –180,000) and lowNe/Nc values (0.0047 –0.048) indicated weak influences of population outbreaks on long-term π. Our findings are consistent with elevatedμ evolving in response to reducedNe and generation time length, with important implications for explaining ...
Source: PLoS Genetics - Category: Genetics & Stem Cells Authors: Source Type: research