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Abstract The mechanisms that underlie senescence are not well understood in insects. Telomeres are conserved repetitive sequences at chromosome ends that protect DNA during replication. In many vertebrates, telomeres shorten during cell division and in response to stress and are often used as a cellular marker of senescence. However, little is known about telomere dynamics across the lifespan in invertebrates. We measured telomere length in larvae, prepupae, pupae, and adults of two species of solitary bees,Osmia lignariaandMegachile rotundata. Contrary to our predictions, telomere length was longer in later developmental stages in bothO. lignariaandM. rotundata.Longer telomeres occurred after emergence from diapause, which is a physiological state with increased tolerance to stress. InO. lignaria, telomeres were longer in adults when they emerged following diapause. InM. rotundata, telomeres were longer in the pupal stage and subsequent adult stage, which occurs after prepupal diapause. In both species, telomere length did not change during the 8 months of diapause. Telomere length did not differ by mass similarly across species or sex. We also did not see a difference in telomere length after adultO. lignariawere exposed to a nutritional stress, nor did length change during their adult lifespan. Taken together, these results suggest that telomere dynamics in solitary bees differ from what is commonly reported in vertebrates and suggest that insect diapause may influence telomere dynamics.
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This content will become publicly available on December 1, 2025
Convergent evolution associated with the loss of developmental diapause may promote extended lifespan in bees
Diapause has long been proposed to play a significant role in the evolution of eusociality in Hymenoptera. Recent studies have shown that shifts in the diapause stage precede social evolution in wasps and bees, however, the genomic basis remains unknown. Given the overlap in molecular pathways that regulate diapause and lifespan, we hypothesized that the evolutionary loss of developmental diapause may lead to extended lifespan among adults, which is a prerequisite for the evolution of eusociality. To test whether the loss of prepupal diapause is followed by genomic changes associated with lifespan extension, we compared 27 bee genomes with or without prepupal diapause. Our results point to several potential mechanisms for lifespan extension in species lacking prepupal diapause, including the loss of the growth hormone PTTH and its receptor TORSO, along with convergent selection in genes known to regulates lifespan in animals. Specifically, we observed purifying selection of pro-longevity genes and relaxed selection of anti-longevity genes within the IIS/TOR pathway in species that have lost prepupal diapause. Changes in selection pressures on this pathway may lead to the evolution of new phenotypes, such as lifespan extension and altered responses to nutritional signals, that are crucial for social evolution.
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- Award ID(s):
- 2142778
- PAR ID:
- 10586446
- Publisher / Repository:
- Genome Biology and Evolution
- Date Published:
- Journal Name:
- Genome biology and evolution
- ISSN:
- 1759-6653
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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