Male-specific alleles in the Ryukyu drywood termite Neotermes sugioi

Abstract

Sex-determination systems often show remarkable diversity in upstream signals, although downstream genes are broadly conserved. Therefore, the downstream genes have been investigated in various taxa, but the most upstream signals determining sex in insects have been well-described mainly in model organisms, including fruit flies and honey bees, and not in hemimetabolous insects such as termites. Identification of sex-linked genetic markers in termites is important to the survey of primary sex-determination signals. Here, we report male-specific alleles at the microsatellite locus NK12-1 in the Ryukyu drywood termite Neotermes sugioi (Kalotermitidae). This study provides the third example of a genetic marker linked with sexual phenotype in termites, which is a small but important step to elucidate the evolutionary process of the sex-determination system in termites.

Keywords: Isoptera; genetic markers; geographical variation; sex determination.

FIGURE 1

Sexual differences in the microsatellite genotype frequencies (NK12‐1) of the Ryukyu drywood termite Neotermes sugioi (Kalotermitidae). In each panel, filled and open bars indicate the data of male and female N. sugioi termites, respectively. All males have the male‐specific alleles (163 and 169 bp)