Thaindian News

Sydney, May 16 (IANS) While causes of male infertility have never been understood, a recent study suggests that genes located in the energy centre of humans, the mitochondria, can now unravel this mystery.

Damian Dowling, evolutionary biologist from Monash University, Australia, who led this study team of Australian and Swedish researchers, explains that mitochondrial genes are unusual because they are passed only from mother to child, reports Science, a journal.

“This seemingly trivial fact actually has an enormous consequence for males. It means that mutations (permanent change in the DNA) in the mitochondria can slip through the quality-control checks unnoticed and therefore build up to high levels, if these mutations are harmful in their effects on males but not on females. This is because all of the screening of mitochondrial mutations is done in females as a result of their maternal inheritance,” Dowling said.

The researchers, who have presented evidence of this process in fruit flies, have also shown that the particular set of mitochondrial genes an individual harbours has major effects on the expression of about 10 percent of all the other genes inside of males, but virtually no effect on females.