Fountain of youth a step closer?
Washington: The `fountain of youth` seems to be one step closer, after scientists have discovered that certain genetic combos give long life to either beetles which have sex or those that don`t.
In its study, an international team, including Asian -origin Tejashwari Meerupati of Uppsala University in Sweden, has uncovered that a small set of genes in mitochondria passed only from mothers to offspring, plays a more dynamic role in predicting life expectancies than ever previously anticipated.
The research discovered that particular mitochondrial haplotypes (mitochondria is a membrane-enclosed organelle in eukaryotic cells) were linked to life expectancies of females in the beetle species Callosobruchus maculatus.
"What we found in these beetles that some combinations of mitochondrial and nuclear genomes confer long life in virgin females, but these are not the same combinations that
result in long life in females that mate once, or in females that mate many times.
"Clearly, the genetic determinants underlying life expectancies are complex. As we unravel this complexity, we draw closer to the day in which we might use the genetic info
encoded in mitochondria to assist in development of therapies that slow the onset of ageing in humans," lead scientist Dr Damian Dowling of Monash University said.
In animals, most of the genetic material that controls bodily functions is found inside the cell nucleus. This is the nuclear genome - it is passed on from generation to generation
through both mothers and fathers, and it encodes somewhere between 14 thousand and 40 thousand proteins.
However, a separate genome exists that is found only within the energy-producing factories of our cells – the mitochondria. To put things in perspective, the mitochondrial
genome is tiny, encoding just 13 proteins. Despite being so small, it can pack a punch when it comes to its ability to affect a range of fundamental biological processes.
"Our findings are part of a broader research agenda in which we are elucidating the ways in which mitochondrial genomes have shaped our evolutionary past and present.
"What we are finding is that natural variation in this diminutive genome results in a huge range of effects on metabolism, mating behaviour and reproductive biology,
including male fertility.
"At the outset of our research program, we suspected that the evolutionary significance of the mitochondria had probably been underestimated by scientists that have come
before us, but even we have been continually surprised by the magnitude and ubiquity of the effects that we have uncovered.
"We suspect that this genome still harbours many more secrets awaiting discovery," Dr Dowling wrote in the `American Naturalist` journal.