Male’s influence on the primary sex ratio bias in Ryukyu drywood termite

Selfish genetic elements (SGEs) increase their transmission efficiency relative to the rest of individual genome, which is often deleterious fitness. Theoretical studies have suggested that intragenomic conflict over sex ratio distortion between SGEs and genome should lead evolution sex-determining systems. However, in insects, there are relatively few other than those on Dipterans, makes it difficult understand role insect determination. This partially due difficulties observing under field conditions. The effect masked by counter-evolution resistance genes. Interpopulation cross-breeding experiments effective detect If these populations different genes, reveal existence collapsing evolutionary antagonistic state. Ryukyu drywood termites Neotermes sugioi , distributed Islands, show male-biased ratios pseudergates, nymphs, alates soldiers both Okinawa Ishigaki but degrees bias been reported islands. Male-specific microsatellite alleles this species, allowed us identify eggs young larvae. In study, we used locus with male-specific investigate primary colonies islands offspring obtained through were not Ishigaki. Cross-breeding showed males tend a offspring, do not. result consistent hypothesis male species caused SGEs, even though phylogenetically distant from Diptera. Accumulation knowledge conflicts wide range taxa might be an important step toward elucidating mechanisms diversification determination systems insects.