Divergent selection on opsins drives incipient speciation in Lake Victoria cichlids.
Divergent natural selection acting on ecological traits, which also affect mate choice, is a key element of ecological speciation theory, but has not previously been demonstrated at the molecular gene level to our knowledge. Here we demonstrate parallel evolution in two cichlid genera under strong divergent selection in a gene that affects both. Strong divergent natural selection fixed opsin proteins with different predicted light absorbance properties at opposite ends of an environmental gradient. By expressing them and measuring absorbance, we show that the reciprocal fixation adapts populations to divergent light environments. The divergent evolution of the visual system coincides with divergence in male breeding coloration, consistent with incipient ecological by-product speciation.
Terai
Yohey
Y
Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.
Seehausen
Ole
O
Sasaki
Takeshi
T
Takahashi
Kazuhiko
K
Mizoiri
Shinji
S
Sugawara
Tohru
T
Sato
Tetsu
T
Watanabe
Masakatsu
M
Konijnendijk
Nellie
N
Mrosso
Hillary D J
HD
Tachida
Hidenori
H
Imai
Hiroo
H
Shichida
Yoshinori
Y
Okada
Norihiro
N
D000351:Africa, Eastern; D000483:Alleles; D000818:Animals; D001522:Behavior, Animal; D023681:Cichlids / Q000145:classification* / Q000235:genetics*; D005618:Fresh Water; D049810:Genetic Speciation; D008297:Male; D008969:Molecular Sequence Data; D010860:Pigments, Biological / Q000737:chemistry / Q000378:metabolism; D017299:Rod Opsins / Q000235:genetics*; D012641:Selection, Genetic; D013057:Spectrum Analysis
D010860:Pigments, Biological; D017299:Rod Opsins