Mitochondrial genome anatomy and species-specific lifespan
G. Lehmann, A. Budovsky, K. Muradian, V. Fraifeld
Department of Microbiology and Immunology, Center for Multidisciplinary Research in Aging, Ben-Gurion University of the Negev, POB 653, Beer-Sheva 84105, Israel
Several lines of evidence implicate mtDNA in the control of aging and
longevity. Yet, there is a limited number of studies attempting to
compare the basic mtDNA characteristics with species-specific (maximum)
lifespan (MLS). Therefore, we examined correlative links between mtDNA
composition and MLS of multicellular eukaryotes. For this purpose, we
built a new database containing 144 species from 11 classes. Among the
species examined, mtDNA size varied within a relatively narrow range,
from 13,794 to 20,001 bps (1.45-fold difference), while the difference
in the MLS was 7,650-fold (from 0.16 to 122.4 years). A significant
negative correlation between mtDNA size and MLS was found in primates.
It was however insignificant, when all the taxa or all mammalian
species were analyzed. In contrast, we found a strong negative
correlation between MLS and mitochondrial AT ratio for all taxa
examined. Similar results were obtained for A+T base pair absolute
count. Of note, MLS inversely correlates with the number of pyrimidine
dimers. The latter could be attributed to an increased formation of
cyclobutane pyrimidine dimers due to the lack of nucleotide excision
repair in mitochondria (the main mechanism to eliminate this type of
mutations). The results suggest that the MLS may be associated with
stability and mutability of mtDNA and call for further investigation of
mitochondrial genome anatomy.
Key words:
mtDNA, maximum lifespan
Problems or questions regarding this site should be directed to
the organiser