Discrepancy in the degree of population differentiation between color-morph frequencies and neutral genetic loci in the damselfly Ischnura senegalensis in Okinawa Island, Japan

Abstract

Evaluation of relative contribution of natural selection and stochastic processes to population differentiation has been of great interest in evolutionary biology. In a damselfly, Ischnura senegalensis, females show color dimorphism (gynochrome vs. androchrome), and color-morph frequencies are known to greatly vary among local populations within Okinawa Island, a small island of Ryukyu Archipelago, Japan. In this study, to examine the effects of natural selection and stochastic processes on the within-island variation in color-morph frequencies, we compared the degree of population differentiation at the color-morph locus with that at a mitochondrial DNA region and ten nuclear microsatellite loci. F ST values at the neutral loci were close to zero, indicating presence of sufficient gene flow (dispersal of adult individuals) between the local populations. In contrast, F ST values at the color-morph locus were significantly different from zero. These results suggest that variation in female color-morph frequencies observed among local populations in Okinawa Island has been caused by divergent selection acting on the phenotype and/or genes tightly linked with the color locus.

Evolutionary history of a beautiful damselfly, Matrona basilaris, revealed by phylogeographic analyses: the first study of an odonate species in mainland China

“…Odonata (damselflies and dragonflies), an ancient insect order, are extremely sensitive to the alteration of their habitats (Khan 2015), which makes them good "thermometers" of environment quality (Silva et al 2010;Kietzka et al 2016) and therefore good study subjects for phylogeography (Cordoba-Aguilar and Cordero-Rivera 2005). A number of phylogeographic studies concerning Odonata have been published (Kahilainen et al 2014;Monroe and Britten 2014;Inomata et al 2015;Jones and Jordan 2015;Swaegers et al 2015;Ware et al 2014), some related to island species of China (Lee and Lin 2012;Xue et al 2017). However, until now, no comparable research related to odonate species in mainland China has been conducted.…”

Genome‐wide population genetic analysis identifies evolutionary forces establishing continuous population divergence

“…Likewise, if populations only extend over small spatial scales with small environmental variation, divergent selection would hardly be detected. In fact, recent genetic analyses on polymorphic damselflies did not consider environmental distance among populations, and thus detected only one of the two selective factors (Andre´s et al 2000;Wong et al 2003;Abbott et al 2008;Sa´nchez-Guille´n et al 2011;Inomata et al 2015). In damselfly, female morph frequency is known to change with latitude (Gosden et al 2011;Takahashi et al 2011) and altitude (Cooper 2010).…”

The effect of thedoublesexgene in body colour masculinization of the damselflyIschnura senegalensis

“…Although it is not possible to determine the colour morphs of larvae, female morph frequency differs significantly among populations (e.g. gynomorph frequency is high (greater than 90%) at Makabe, and low (less than 40%) at Kakinohana), despite small genetic and geographical distances among populations on Okinawa Island [43].…”