Though termites are responsible for some $40 billion a year in damage and efforts to control them, they also give a glimpse into the development of eusociality. Researchers led by Arizona State University's Jürgen Liebig sequenced the genome as well as stage-specific transcriptomes of the dampwood termite Zootermopsis nevadensis and compared them to that of previous work on eusocial Hymenoptera. Eusociality in termites evolved separately from that of the ants and bees of Hymenoptera.
As they report in Nature Communications, they uncovered both similarities and differences in expansion of genes linked to sex and eusociality.
For instance, Liebig and his colleagues uncovered large expansions in genes associated with spermatogenesis in termites as compared to ants and bees. This, they note, could reflect the different roles males have in the insects' caste systems. In termites, males live longer and mate more often than their ant or bee counterparts. Additionally, male Z. nevadensis activate and deactivate their testes with the seasons, which the researchers say likely necessitated additional adaptations.
The researchers also note that termite genes are highly methylated and undergo alternative splicing and that may contribute to caste differentiation.
"In honeybees, this process of methylation sets the fate of individual animals, determining their place in the caste system," adds LiveScience. "The new findings suggest a similar process may be at play in termites."