Search

Insulin is a protein hormone that controls the metabolism of sugar, fat and protein via signal transduction in cells, influencing growth and developmental processes such as reproduction and ageing. From nematodes to fruit flies, rodents and other animals, glucose signalling mechanisms are highly conserved. Reproductive termites (queens and kings) exhibit an extraordinarily long lifespan relative to non-reproductive individuals such as workers, despite being generated from the same genome, thus providing a unique model for the investigation of longevity. The key reason for this molecular mechanism, however, remains unclear. To clarify the molecular mechanism underlying this phenomenon, we sequenced the transcriptomes of the primary kings (PKs), primary queens (PQs), male (WMs) and female (WFs) workers of the lower subterranean termite Reticulitermes chinensis. We performed RNA sequencing and identified 33 insulin signalling pathway-related genes in R. chinensis. RT-qPCR analyses revealed that EIF4E and RPS6 genes were highly expressed in WMs and WFs workers, while mTOR expression was lower in PKs and PQs than in WMs and WFs. PQs and PKs exhibited lower expression of akt2-a than female workers. As the highly conserved insulin signalling pathway can significantly prolong the healthspan and lifespan, so we infer that the insulin signalling pathway regulates ageing in the subterranean termite R. chinensis. Further studies are recommended to reveal the biological function of insulin signalling pathway-related genes in the survival of termites to provide new insights into biomolecular homeostasis maintenance and its relationship to remarkable longevity.

Aging and longevity is a dynamic, chronological process assumed to originate from several hallmarks causing archetypal and beguiling cycles with incredible natural diversity. This phenomenon is widely observed in different animals, and the estimated age of Drosophila melanogaster, Caenorhabditis elegans,Daphnia longispina are a few days to weeks. Reproductive termites live for 30 years, although the root cause of longevity in termite castes is still debated for molecular and cellular changes. Insulin and insulin signaling pathway‐related (IIS) genes are important metabolic factors (glucose) highly conserved in lower to higher organisms. Therefore, in this study, we pooled Reticulitermes chinensis castes as primary king (PK), primary queen (PQ), ergatoid king "SWRK" and queen "SWRQ", male (WM), and female (WF) workers. We determined transcriptome sequencing of R. chinensis castes as a model organism for longevity to investigate the insulin signaling pathway and longevity genes. Through RNA‐sequencing, we identified 35 IIS‐pathway‐related genes out of 343 to the KEGG pathway in ergatoid king and queen, PK, PQ, WM, and WF. Among these genes, Tsc2, akt2‐a, mTOR, EIF4E, Pdk1, and RPS expressed highly in ergatoid king and queen, PK, and PQ. However, a significant cornerstone tradeoff between reproductive and non‐reproductive efforts for early life is essential for evolutionary longevity. The present study concludes that a highly conserved IIS‐pathway is evidence for the prolonged termite reproductive life span. We recommended devoting insulin signaling pathway genes to their biological function for termite survival and new insights into the maintenance and relationships between biomolecular homeostasis and remarkable longevity. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]