Physiology · May 2026
Metamorphosis and its Impact on Cellular Age in Specific Tissues
By Humpherys A, Rinehart JD, Szejner‐Sigal A et al.
Cellular aging is a complex process that affects fitness, reproduction and susceptibility to disease. Understanding the factors that regulate cellular age could provide insights into how to combat this inevitable decline. Telomere attrition is a cellular hallmark used to measure age. In most organisms, telomere length decreases with subsequent cell divisions until they reach a critically short length. However, in some insects such as the alfalfa leafcutter bee, Megachile rotundata, and the orchard mason bee, Osmia lignaria, telomere length is longer in later developmental stages as insects age. To further examine this phenomenon, we used the moth, Manduca sexta, to explore the impact of metamorphosis on telomere length. Metamorphosis involves intense structural remodeling using stem cell-like imaginal cells, often replacing larval tissues with comparable adult tissues. Consequently, metamorphosed adults could possess “old” larval tissues and “new” adult tissues, which calls into question the cellular age of these different tissues. We hypothesized that metamorphosis alters the cellular age of specific tissues. Using qPCR, we measured relative telomere length and telomerase activity in specific tissues of fourth and fifth instar larvae as well as adults following metamorphosis. We predicted that “new” adult tissues would possess longer telomeres than non-remodeled tissues. We also predicted that telomerase would be more abundantly expressed in late larval stages to prepare for the tissue development that occurs during metamorphosis. Understanding how cellular age is regulated in insects could clarify how developmental processes impact telomere length in different tissues and reveal cellular mechanisms that contribute to telomere maintenance. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.