TY - JOUR T1 - Fitness landscapes support the dominance theory of post-zygotic isolation in the mussels Mytilus edulis and M. galloprovincialis A1 - Bierne,Nicolas A1 - Bonhomme,Francois A1 - Boudry,Pierre A1 - Szulkin,M A1 - David,Pierre AD - UMII, CNRS, UMR 5171,Stn Mediterraneenne Environm Littoral, IFREMER,Lab Genome Populat Interact Adaptat, F-34200 Sete, France. AD - CNRS, CEFE, F-34293 Montpellier, France. AD - IFREMER, Lab Genet & Pathol, F-17390 La Tremblade, France. UR - https://archimer.ifremer.fr/doc/00000/1350/ DO - 10.1098/rspb.2005.3440 KW - Mytilus KW - Dobzhansky Muller incopatibilities KW - Post zygotic isolation KW - Negative epistasis KW - Hybrid breakdown KW - Hybrid zone N2 - We studied the genetic basis of post-zygotic isolation in the marine mussels Mytilus edulis and Mytilus galloprovincialis. Evidence was obtained for a high number of recessive Dobzhansky-Muller substitutions in the genome of these two mussel taxa. We analysed the segregation of unlinked diagnostic markers in the progeny of two backcrosses and an F-2 cross, 36 h and 200 days after fertilization. Directional selection favouring M. galloprovincialis genotypes was observed in both kinds of cross. In the F-2, epistatic interactions between each pair of chromosome fragments mapped by the markers were identified in addition. Our results imply that homozygous-homozygous interactions are required for breakdown of coadaptation, in accordance with the dominance theory of post-zygotic isolation. Endogenous post-zygotic selection distributed over many loci throughout the genome provides the missing factor explaining the astonishing persistence and strength of barriers to neutral introgression in such a dispersive taxon as Mytilus. Y1 - 2006/05 PB - Royal Society of London JF - Proceedings of the Royal society of London (B) (Biological sciences) SN - 0962-8452 VL - 273 IS - 1591 SP - 1253 EP - 1260 ID - 1350 ER -