UCI Researchers Use Fruit Flies to Overcome Mortality of Cells
Breakthroughs in the field of biological immortality have redefined the farfetched idea of a fountain of youth by researching fruit flies in order to delay the effects of aging.
The collaborative research efforts of Michael Rose, Professor of Ecology and Evolutionary Biology, Laurence Mueller, Professor of Ecology and Evolutionary Biology, and Casandra Rauser, Ph.D. in Biological Sciences, investigate the idea of postponing aging.
Their work was inspired by a series of papers published during 1991 in the “Journal Science” suggesting that mortality rates do not continue to increase with advanced age but instead level off. Such organisms where mortality rate plateaus are present include yeasts, nematodes, wasps and humans.
“Biological immortality follows aging. This happens because natural selection does not discriminate among genetic effects that act at very late ages because these genetic effects have no impact on fitness. Even in organisms that reproduce at all ages, the force of natural selection is eventually overwhelmed in late life,” Rose said.
In studying the theory of biological immortality, the research team’s objectives were twofold: (1) to explain the idea of biological immortality and (2) to manipulate it in the lab.
In 1996, Rose and Muller published their findings reporting the fulfillment of their first objective in the “Proceedings of the National Academy of Sciences” proving the idea of biological immortality in explicit numerical simulations.
Rose discussed the implications of this finding.
“This theoretical result implied that the transition to biological immortality should evolve in the lab if the timing of last reproduction is changed for enough generations,” Rose said.
This was preceded by experiments using 30 large populations of fruit flies.
“We tested our hypotheses using fruit flies specifically because they are an organism that a lot is already known about, genetically speaking. They are what we consider a ‘model organism’ for genetic studies, especially studies about human diseases,” Rauser said.
Additionally, Muller mentioned that there were two kinds of fruit fly populations studied. One group reproduces only very early in life and the second group reproduces only very late in life.
“By manipulating the timing of reproduction we also alter the magnitude of age-specific selection which is the key to testing these theories,” Muller said.
Their experiment results matched the predictions of the evolutionary theory of biological immorality.
“We were able to make the transition to biological immortality evolve to earlier or later ages, just by controlling evolution in lab fruit flies,” Rose said.
Their results were published in the scientific journal “Evolution” in 2002.
Rauser joined Rose and Mueller’s research collaboration as a graduate student attending UC Irvine.
Prior to Rauser’s participation, Rose and Mueller were working on the evolution of late age mortality. When she joined the lab, the research focus shifted to an investigation of whether fertility acted in a manner similar to mortality.
“We tested whether the deterioration in fertility with age stopped, or slowed, at late ages, similar to the slowing of mortality rates at late ages,” Rauser said. “We found that fertility does act in a manor similar to mortality, which allowed us to conclude that biological mortality in general slows or ceases at late ages, contrary to what was previously believed.”
Throughout the 12 years during which the research team has been studying this subject, they have been assisted by hundreds of UCI undergraduates.
Mueller discussed what they hope people will take away from their research.
“The most important take home message is that aging is not inevitable but rather it is a reflection of our evolutionary history. With a detailed understanding of this process we should be able to discover how to reverse engineer organisms, including humans, to ameliorate the consequences of the aging process,” Muller explained.
The research trio also intend on expanding their research on this subject.
“We are interested in the application of this work specifically to humans, especially the impact of diet on the transition to biological immortality,” Rose said.
In addition to the aforementioned publications, the research team has also published numerous articles on this subject in journals that include, but are not limited to, “Journal of Evolutionary Biology,” “Experimental Gerontology,” and “Rejuvenation Research.”
Rose, Mueller and Rauser are currently writing a book “Does Aging Stop?” on their research.