Masters Theses

Keywords and Phrases

Cellular aging; Life History; Oxidative Stress; Protein damage; Protein oxidation

Abstract

DR and ambient temperature are two environmental factors widely implicated in shaping organismal maintenance and longevity through effects on metabolic rate and oxidative damage. This study tests whether DR and reduced body temperature independently or interactively reduce oxidative protein damage in the gut of tobacco hornworm larvae, a short-lived ectotherm whose life history may constrain typical DR responses. Larvae hatched from eggs were allocated to two feeding regimes (AL and DR) and to 20 °C and 30 °C. At a defined endpoint, guts dissected and homogenized, and analyzed for protein carbonyl content and total protein. Protein damage was expressed as the ratio of carbonyl content to total protein. Results show larvae reared at 20 °C exhibited significantly lower carbonyl/protein ratios than those reared at 30 °C under both feeding regimes. In contrast, DR did not produce a significant reduction in protein carbonylation at either temperature and DR failed to produce a consistent suppression of growth in this system. These findings indicate that, in Manduca sexta larvae, lowered ambient temperature reduces oxidative protein damage in the gut, whereas a 50% DR regimen did not measurably improve this damage metric. The absence of a DR effect is likely mechanistic rather than methodological. Future work should (1) verify DR-induced reductions in growth/food intake across taxa with comparable life histories, and (2) assay complementary damage and repair endpoints to determine the generality and mechanisms by which diet and temperature interact to shape maintenance and ageing in short-lived ectotherms.

Advisor(s)

Hou, Chen

Committee Member(s)

Thimgan, Matthew S.
Huang, Yue-Wern

Department(s)

Biological Sciences

Degree Name

M.S. in Biological Sciences

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2025

Pagination

vii, 37 pages

Note about bibliography

Includes_bibliographical_references_(pages 27-36)

Rights

© 2026 Fahime Taheri , All Rights Reserved

Document Type

Thesis - Open Access

File Type

text

Language

English

Thesis Number

T 12578

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