The remoulding of dietary effects on the fecundity / longevity trade-off in a social insect

Abstract

Background In many organisms increased reproductive effort is associated with a shortened life span. This trade-off is reflected in conserved molecular pathways that link nutrient-sensing with fecundity and longevity. Social insect queens apparently defy the fecundity / longevity trade-off as they are both, extremely long-lived and highly fecund. Here, we have examined the effects of a protein-enriched diet on these life-history traits and on tissue-specific gene expression in a termite species of low social complexity. Results On a colony level, we did not observe reduced lifespan and increased fecundity, effects typically seen in solitary model organisms, after protein enrichment. Instead, on the individual level mortality was reduced in queens that consumed more of the protein-enriched diet – and partially also in workers – while fecundity seemed unaffected. Our transcriptome analyses supported our life-history results. Consistent with life span extension, the expression of IIS (insulin/insulin-like growth factor 1 signalling) components was reduced in fat bodies after protein enrichment. Interestingly, however, genes involved in reproductive physiology (e.g., vitellogenin) were largely unaffected in fat body and head transcriptomes. Conclusion These results suggest that IIS is decoupled from downstream fecundity-associated pathways, which can contribute to the remoulding of the fecundity/longevity trade-off in termites as compared to solitary insects.

High-quality long-read genome assemblies reveal evolutionary patterns of transposable elements and DNA methylation in termites

“…Because Odontotermes sp.2, M. bellicosus and C. secundus have available RNAseq data (published or in-house: Elsner et al 2018, Harrison et al 2018, Monroy Kuhn et al 2019, Lin et al 2021, Rau et al 2023, genome assemblies of these three species were annotated with the Braker3 (v. 3.0.3) pipeline (Gabriel et al 2023). Genome assemblies were first softmasked with RepeatMasker (Smit et al 2013(Smit et al -2015 (see Repeat and transposable element annotation).…”