Seminar in Biological Mechanisms of Aging and Cancer/Epigenetic Alterations

Epigenetic refers to changing the appearance of an organism, phenotype, that can be inherited without changing the DNA information within the body. However, it is unknown how these epigenetic markers are passed down from generation to generation. “The Hallmarks of Aging” has identified epigenetic alterations as one of the major causes of aging. As aging progresses, changes in the methylation, the process in which a carbon and 3 hydrogens are added to DNA, occur in DNA, histones, and chromatin.

An attempt at a graphical abstract summarizing Greer et al (2011)

As an example of research that has been done relating to this hallmark of aging, we discussed a paper published by Greer et al in 2011 [1]. These authors studied whether or not ASH-2, WDR-5, and SET-2 components of the H3K4me3, histone H3 lysine trimethylation complex, could regulate the lifespan of the descendants if they were disturbed in the parental generation in C.elegans. They observed that if these components were disturbed, the lifespan of the descendants of C.elegans did indeed increase. However, the generational increase in lifespan was not everlasting and only continued on for three generations. The authors also concluded that in order for the generational increase in lifespan to occur the organism must also have a functioning germline and the protein RBR-2.

  1. Greer, E. L., Maures, T. J., Ucar, D., Hauswirth, A. G., Mancini, E., Lim, J. P., … Brunet, A. (2011). Transgenerational Epigenetic Inheritance of Longevity in C. elegans. Nature, 479(7373), 365–371.