Identification, Characterization and Expression of Methuselah-Like Genes in Dastarcus helophoroides (Coleoptera: Bothrideridae)

Dastarcus helophoroides, which has a relatively longer lifespan compared to other insects, is one of the most effective natural enemies of many large-body long-horned beetles. Methuselah (Mth) is associated with the lifespan, stress resistance, and reproduction in Drosophila melanogaster, but Mth is not present in non-drosophiline insects. A number of methuselah-like genes (mth-likes, mthls) have been identified in non-drosophiline insects, but it is still unknown whether they are present in Dastarcus helophoroides. We identified three novel mth-like genes in D. helophoroides: mth-like1, mth-like2, and mth-like5, and carried out bioinformatic analysis based on the full-length nucleic acid sequences and deduced amino acid sequences. Real-time quantitative polymerase chain reaction (RT-qPCR) showed variations in expression patterns of mth-like genes in different tissues (highly expressed in reproductive systems) and at different developmental stages, indicating that mth-likes were likely be involved in reproduction and development. The altered mRNA expression in aging adults and under oxidation, high temperature, and starvation stress, indicated that mth-like genes were likely to be involved in aging and the resistance of oxidation, high temperature, and starvation. These results characterize, for the first time, the basic properties of three mth-like genes from D. helophoroides that probably play important roles in development, aging, reproduction, and stress resistance.