Professor Daniel Martinez Awarded $1.26 Million Grant to Study Mechanisms Related to Aging in Hydra
Professor of Biology Daniel Martínez has received a five-year $1,263,358 grant from the National Institutes of Health for research titled “Mechanisms underlying lack of senescence and inducible senescence in members of the genus Hydra.” Senescence is the biological process of aging.
Work on the mechanisms of longevity control in invertebrate species such as the nematode worm Caenorhabditis elegans and the furitfly Drosophila melanogaster has already provided insight into the causes of human aging-related disease. Unlike humans, however, these two species are relatively short-lived. Caenorhabditis elegans lives approximately 2-3 weeks, and Drosophila melanogaster has a lifespan of around 3 months. “A potentially immortal species like Hydra has the potential to provide different types of information than that provided by short-lived invertebrate models like C. elegans and D. melanogaster,” explains Martínez.
The NIH grant will be used to investigate the differences in regulation of lifespan in two closely related species, Hydra vulgaris and Hydra oligactis. The researchers will focus on the possible roles of signals from the germline, proteins involved in the heat shock response, and the transcription factor FoxO.
Existing data suggests that Hydra vulgaris does not show increased mortality with age while a closely related species, H. oligactis, does show increased mortality as well as physiological deterioration following induction of sexual reproduction.
Aspects of the biology of the Hydra vulgaris and Hydra oligactis suggest that some mechanisms affecting lifespan in other animals may contribute to the difference between the two species.
According to Martínez, “Working with animals treated to eliminate the stem cells which produce gametes, we will investigate the possibility that, as in Caenorhabditis elegans and Drosophila melanogaster, germ cells in H. oligactis can reduce lifespan. By examining gene expression and producing transgenic animals which inducibly overexpress genes of interest, we will investigate the roles of genes involved in the heat shock response and the role of the transcription factor FoxO in H. vulgaris and in H. oligactis before and after induction of sexual reproduction and senescence.
The work will be done in collaboration with Dr. Diane Bridge, of Elizabethtown College, and will include undergraduate students from both institutions, as well as a postdoctoral fellow to be housed at Pomona College. An earlier collaboration between Martínez and Bridge resulted in the recent publication of a paper in PLos One, which included Pomona College graduate Emily Marcinkevicius ’06: Bridge D., A. Theofiles, R. Holler, E. Marcinkevicius, R. Steele, and D. Martínez, “FoxO and Stress Responses in the Cnidarian Hydra vulgaris” (PLoS One, 5, 2010).
Martínez, who has been studying the hydra since graduate school, was the first hydra scholar to provide strong evidence that the hydra, unlike most organisms, seems never to age. He joined Pomona College in 1997 and is currently chair of the Biology Department.