Telomerase activity is up-regulated in the fat body of pre-diapause queens of bumble bee (Bombus terrestris)
The article in IBMB supports the hypothesis that lifespan in primitive eusocial insect species is regulated in a different way than it is in advanced eusocial insects.
Photo description: DNA synthesis in the fat body of young, pre-diapause queens. A. DNA was stained using DAPI (blue signals). B. DNA synthesis was visualized using EdU (green signals). Stars indicate nuclei of adipocytes, arrows indicate oenocytes.
The attrition of telomeres, the ends of eukaryote chromosomes, and activity of telomerase, the enzyme that restores the telomere length, play a role in ageing processes and act as indicators of biological age. The remarkable feature of advanced eusocial insects is extraordinary longevity of reproductive individuals (queens and kings) compared to those from non reproductive castes (workers and soldiers) within a given species, with a proposed link towards up-regulation of telomerase activity in somatic tissues of reproductives. Given this, eusocial insects provide excellent model systems for research of ageing. In this study, we tested telomerase activity and telomere length in Bombus terrestris, which is a primitively eusocial insect species with several distinct features compared to advanced social insects, such as honeybees or termites.
In somatic tissues of B. terrestris telomerase activity was found to be enhanced only in the fat body of young pre-diapause queens, where associated with the massive DNA synthesis. We speculate that the up-regulation of telomerase activity in the fat body of pre-diapause queens is the essential requirements for rapid intensifying of metabolic activity to build-up a sufficient energy reserve prior to diapause. Data support our hypothesis that lifespan in B. terrestris is regulated in a different way than it is in advanced social insects, and longevity of bumblebee queens are rather enabled by the long-period of diapause. Further, our study gave a hint that telomerase activity might be in a direct correlation with mating process as well as with nutrient-sensing pathways, however, more detail study must be performed to verify these relationships or uncover more hidden insights.
Koubová J., Jehlík T., Kodrík D., Sábová M., Šima P., Sehadová H., Závodská R., Čapková Frydrychová R. (2019) Telomerase activity is upregulated in the fat bodies of pre-diapause bumblebee queens (Bombus terrestris). Insect Biochemistry and Molecular Biology 115 : 103241. DOI: 10.1016/j.ibmb.2019.103241