Date of Award


Document Type

Open Access Dissertation


Biological Sciences

First Advisor

Rekha C. Patel


Aging is a ubiquitous process pertaining to all biological systems around the planet. Although much has been learned from studies so far on the molecular mechanisms that lead to aging, a complete understanding of a healthy life span and longevity still eludes us. In this dissertation, we will examine the use of a freshwater microcrustacean Daphnia as a model system for studies on the biology of aging. The Introduction chapter presents a review of the general molecular alterations associated with cellular and organismal aging, and discusses the core model organisms currently used to study the aging process. The introduction chapter includes a brief discussion of the advantages offered by Daphnia as a model system. The chapters 2-5 present the results of our experiments using Daphnia that examine the pathways established to play a regulatory role in the aging process. The Chapter 2 presents a comparison of the telomere length, telomerase activity, and telomerase processivity in the two ecotypes, the short-lived Daphnia pulex and the long-lived Daphnia pulicaria. The Chapter 3 presents a study of the heat shock responses in both short- and long-lived ecotypes. Chapter 5 describes a new method for fast and effective RNA interference in Daphnia. This method is expected to be widely useful for all Daphnia biologists, as no method was yet available for RNAi in adult Daphnia. Chapter 4 describes a characterization Daphnia Sir2 mRNA levels and activity during life span and examines the effects of RNA interference mediated Sir2 knockdown on lifespan and survival following proteotoxic stress. Overall, in this thesis we establish Daphnia as a new model organism for research on aging and offer novel insights into stress response and telomerase pathways in Daphnia.


© 2015, Charles Andrew Shumpert

Included in

Biology Commons