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RAD‐Seq derived markers flank the shell colour and banding loci of the Cepaea nemoralis supergene
Author(s) -
Richards Paul M.,
Liu M. Maureen,
Lowe Natalie,
Davey John W.,
Blaxter Mark L.,
Davison Angus
Publication year - 2013
Publication title -
molecular ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.619
H-Index - 225
eISSN - 1365-294X
pISSN - 0962-1083
DOI - 10.1111/mec.12262
Subject(s) - biology , supergene (geology) , genetics , evolutionary biology , centimorgan , ecology , gene mapping , gene , mineral , chromosome
Studies on the classic shell colour and banding polymorphism of the land snail C epaea played a crucial role in establishing the importance of natural selection in maintaining morphological variation. Cepaea is also a pre‐eminent model for ecological genetics because the outward colour and banding phenotype is entirely genetically determined, primarily by a ‘supergene’ of at least five loci. Unfortunately, progress in understanding the evolution and maintenance of the C epaea polymorphism stalled, partly because of a lack of genetic markers. With a view to re‐establish C epaea as a prominent model of molecular ecology, we made six laboratory crosses of C epaea nemoralis , five of which segregated for shell ground colour ( C ) and the presence or absence of bands ( B ). First, scoring of colour and banding in 323 individuals found no recombination between the C and B loci of the supergene. Second, using restriction site–associated DNA sequencing ( RAD ‐ S eq) of two parents and 22 offspring, we identified 44 anonymous markers putatively linked to the colour ( C ) and banding ( B ) loci. The genotype of eleven of the most promising RAD ‐ S eq markers was independently validated in the same 22 offspring, then up to a further 146 offspring were genotyped. The closest RAD ‐ S eq markers scored are within ~0.6 centimorgan (cM) of the C ‐ B supergene linkage group, with the combined loci together forming a 35.8 cM linkage map of markers that flank both sides of the C epaea C ‐ B supergene.