The Contribution of Transposons to Differences in Life Span Between Species

Transposable elements in the nuclear genome, also called transposons, are remnant DNA sequences left over from past, often ancient viral infections. A transposon is capable of hijacking the intricate machineries of gene expression to insert further copies of itself into the genome if not suppressed, producing what is effectively DNA damage as these haphazard insertions break existing gene sequences. Further, the transcription of transposon DNA produces viral-like RNA that can provoke an inflammatory innate immune response when present in the cell. Unfortunately, the suppression of transposons weakens with age, allowing these issues to arise and contribute to degenerative aging. It is entirely unclear as to exactly how much of aging and cancer risk can be attributed to activation of transposons. Absent a means to safely shut down transposon activity near entirely in old animals, efforts to better understand the size of the problem must rely on more indirect approaches. Thus the research community undertakes studies such as the one outlined in today's open access paper. The authors looked over the genomes of selected small mammals with short and long life spans, and compared the differing burden of transposon insertions. It appears that short-lived species at a given body mass tend to have a greater number of potentially active transposons, which might be used to apply some bounds to the degree to which transposon activation constrains life span. Comparative analy...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs