FN Archimer Export Format
PT J
TI A high load of non-neutral amino-acid polymorphisms explains high protein diversity despite moderate effective population size in a marine bivalve with sweepstakes reproduction
BT 
AF HARRANG, Estelle
   LAPEGUE, Sylvie
   MORGA, Benjamin
   BIERNE, Nicolas
AS 1:1;2:1;3:1;4:2,3;
FF 1:PDG-RBE-SG2M-LGPMM;2:PDG-RBE-SG2M-LGPMM;3:PDG-RBE-SG2M-LGPMM;4:;
C1 IFREMER, Lab Genet & Pathol, F-17390 La Tremblade, France.
   Univ Montpellier 2, F-34095 Montpellier 2, France.
   CNRS, Inst Sci Evolut, Stn Mediterraneenne Environm Littoral, UMR5554, F-34200 Sete, France.
C2 IFREMER, FRANCE
   UNIV MONTPELLIER, FRANCE
   CNRS, FRANCE
SI LA TREMBLADE
SE PDG-RBE-SG2M-LGPMM
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-univ-france
IF 2.511
TC 21
UR https://archimer.ifremer.fr/doc/00125/23610/21444.pdf
LA English
DT Article
DE ;nucleotide polymorphism;marine bivalve;deleterious mutations;genetic load;Ostrea edulis
AB Marine bivalves show among the greatest allozyme diversity ever reported in Eukaryotes, putting them historically at the heart of the neutralist-selectionist controversy on the maintenance of genetic variation. Although it is now acknowledged that this high diversity is most probably a simple consequence of a large population size, convincing support for this explanation would require a rigorous assessment of the silent nucleotide diversity in natural populations of marine bivalves, which has not yet been done. This study investigated DNA sequence polymorphism in a set of 37 nuclear loci in wild samples of the flat oyster Ostrea edulis. Silent diversity was found to be only moderate (0.7%), and there was no departure from demographic equilibrium under the Wright-Fisher model, suggesting that the effective population size might not be as large as might have been expected. In accordance with allozyme heterozygosity, nonsynonymous diversity was comparatively very high (0.3%), so that the nonsynonymous to silent diversity ratio reached a value rarely observed in any other organism. We estimated that one-quarter of amino acid-changing mutations behave as neutral in O. edulis, and as many as one-third are sufficiently weakly selected to segregate at low frequency in the polymorphism. Finally, we inferred that one oyster is expected to carry more than 4800 non-neutral alleles (or 4.2 cM-1). We conclude that a high load of segregating non-neutral amino-acid polymorphisms contributes to high protein diversity in O. edulis. The high fecundity of marine bivalves together with an unpredictable and highly variable success of reproduction and recruitment (sweepstakes reproduction) might produce a greater decoupling between Ne and N than in other organisms with lower fecundities, and we suggest this could explain why a higher segregating load could be maintained for a given silent mutation effective size.
PY 2013
PD FEB
SO G3-genes Genomes Genetics
SN 2160-1836
PU Genetics Soc Am
VL 3
IS 2
UT 000314881600018
BP 333
EP 341
DI 10.1534/g3.112.005181
ID 23610
ER

EF