著者

Ryutaro Miyagi Yohey Terai

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.88, no.3, pp.145-153, 2013 (Released:2013-09-11)

参考文献数

76

被引用文献数

11 14

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The amazing coloration shown by diverse cichlid fish not only fascinates aquarium keepers, but also receives great attention from biologists interested in speciation because of its recently-revealed role in their adaptive radiation in an African lake. We review the important role of coloration in the speciation and adaptive evolution of Lake Victoria cichlids, which have experienced adaptive radiation during a very short evolutionary period. Mature male cichlids display their colors during mate choice. The color of their skin reflects light, and the reflected light forms a color signal that is received by the visual system of females. The adaptive divergence of visual perceptions shapes and diverges colorations, to match the adapted visual perceptions. The divergence of visual perception and coloration indicates that the divergence of color signals causes reproductive isolation between species, and this process leads to speciation. Differences in color signals among coexisting species act to maintain reproductive isolation by preventing hybridization. Thus, the diversity of coloration has caused speciation and has maintained species diversity in Lake Victoria cichlids.

著者

Saki Sunaga Noriyoshi Akiyama Ryutaro Miyagi Aya Takahashi

出版者

日本遺伝学会

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

pp.15-00061, (Released:2016-03-25)

被引用文献数

3

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Molecular mechanisms underlying standing genetic variation of an ecologically relevant trait such as pigmentation trait variation in a model insect, Drosophila melanogaster, are relevant to our understanding of different kinds of intergenomic interactions. In this study, we focused on the association between body pigmentation and stress resistance, and on genotype-by-environment interaction, both of which are likely to contribute to the persistence of phenotypic variation in a natural population. First, we detected a significant association between pigmentation traits in females and starvation resistance (darker strains were weaker) and a weak association between pigmentation and chill coma recovery time (darker strains showed shorter recovery time) among 20 inbred strains from the Drosophila melanogaster Genetic Reference Panel (DGRP), which originated from a natural population in North America. These associations revealed a complex relationship between body pigmentation and physiological traits that may give rise to balanced selective forces acting on the traits under fluctuating environmental conditions. Second, using four of the DGRP strains, a substantial degree of genotype (strain) × environment (rearing temperature) interaction was detected among expression levels of the genes encoding effector enzymes in the melanin biosynthesis pathway. These interactions can potentially reduce the efficiency of purifying selection on the pigmentation traits over a wide range of temperature conditions. Finally, we discuss possible mechanisms that contribute to the maintenance of the standing pigmentation variation in this species.