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Genomic architecture of habitat‐related divergence and signature of directional selection in the body shapes of Gnathopogon fishes
Author(s) -
Kakioka Ryo,
Kokita Tomoyuki,
Kumada Hiroki,
Watanabe Katsutoshi,
Okuda Noboru
Publication year - 2015
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.13309
Subject(s) - biology , selection (genetic algorithm) , directional selection , divergence (linguistics) , evolutionary biology , signature (topology) , habitat , genetic architecture , ecology , genetics , genetic variation , gene , phenotype , linguistics , philosophy , geometry , mathematics , artificial intelligence , computer science
Evolution of ecomorphologically relevant traits such as body shapes is important to colonize and persist in a novel environment. Habitat‐related adaptive divergence of these traits is therefore common among animals. We studied the genomic architecture of habitat‐related divergence in the body shape of Gnathopogon fishes, a novel example of lake–stream ecomorphological divergence, and tested for the action of directional selection on body shape differentiation. Compared to stream‐dwelling Gnathopogon elongatus, the sister species Gnathopogon caerulescens, exclusively inhabiting a large ancient lake, had an elongated body, increased proportion of the caudal region and small head, which would be advantageous in the limnetic environment. Using an F 2 interspecific cross between the two Gnathopogon species (195 individuals), quantitative trait locus ( QTL ) analysis with geometric morphometric quantification of body shape and restriction‐site associated DNA sequencing‐derived markers (1622 loci) identified 26 significant QTL s associated with the interspecific differences of body shape‐related traits. These QTL s had small to moderate effects, supporting polygenic inheritance of the body shape‐related traits. Each QTL was mostly located on different genomic regions, while colocalized QTL s were detected for some ecomorphologically relevant traits that are proxy of body and caudal peduncle depths, suggesting different degree of modularity among traits. The directions of the body shape QTL s were mostly consistent with the interspecific difference, and QTL sign test suggested a genetic signature of directional selection in the body shape divergence. Thus, we successfully elucidated the genomic architecture underlying the adaptive changes of the quantitative and complex morphological trait in a novel system.