Year: 2026
Type: dissertation
Abstract: Aging is characterized by a progressive decline in physiological function, leading to increased vulnerability to disease and death. However, it remains unclear whether organismal survival is primarily limited by the failure of certain critical tissues or by the cumulative deterioration of multiple physiological systems. Although age-related changes in individual organs have been widely studied, the consequences of experimentally disrupting different adult cell populations remain difficult to compare. This study investigated how adult survival responds to conditional induction of the pro-apoptotic gene grim in different GAL4-defined populations of Drosophila melanogaster. Using the GAL4/UAS system and temperature-sensitive GAL80ts regulation, developmental survival was first examined with ten GAL4 drivers at 18°C. Nine drivers associated with muscle, fat body, tracheal, and neural populations were subsequently tested in adult lifespan experiments following a temperature shift to 30°C. Males and females were analyzed separately, and whole-body CPRG assays were used to assess changes in GAL4-dependent reporter activity. GAL80ts allowed adult recovery in several crosses that otherwise showed severe developmental lethality, although substantial developmental loss persisted with 24B. In adult experiments, 24B produced the strongest survival phenotype, reducing mean lifespan by approximately 88–96% across replicates and sexes. DJ694, DJ634, and Tr also caused pronounced lifespan reductions, while DJ626 showed more moderate but consistent effects. In contrast, Mef2 did not consistently shorten lifespan. CPRG activity decreased in several groups, but these changes did not consistently correspond to the magnitude of lifespan reduction. Together, these findings demonstrate that adult survival responds differently to conditional grim induction across GAL4-defined populations. Although the extent of cell loss remains unconfirmed, the results identify populations associated with strong survival responses and provide a basis for further investigation of how disruption of different cell populations affects organismal survival.
Author: Wang, Xinyi
Institution: Queen's University
Language: English
Subfield: Aging
Domain: Life Sciences
Open Access status: green
Funder: Queen's University
OpenAlex ID: W7225219522