London, June 6. A genetic cousin of DNA has been discovered in mouse
testicles. These are a new class of small RNAs. Small RNAs are known
to regulate key processes in human health .
RNA interference is one important way that the body can shut off genes
of the invading pathogens.
Greg Hansom of Cold Spring Harbor Laboratory in New York and Thomas
Tuschl at the Rockefeller University, also in the same US city, found
the new class of RNAs by cataloguing the entire RNA content of mouse
testicles, according to the Monday issue of the magazine Nature.
The scientists decided to check whether the new RNAs might be
associated with a set of mysterious yet important proteins, called
Piwi proteins, which are expressed in the testicles, and when shut
off, mice are unable to make normal sperm.
The scientists pulled individual Piwi proteins out of mouse testis and
checked what came along with them and found strands of the mysterious
new RNAs stuck to the Piwi proteins.
They have named the new molecules 'Piwi-interacting RNAs' - piRNAs for short.
The scientists also know that similar types of RNAs exist in zebrafish
and flies, and in human testes.
Given that mice need piRNAs and Piwi proteins to make sperm, the
scientists are now intrigued by the idea that piRNAs and Piwi proteins
might control some of the huge changes that give rise to sperm - for
instance, the cell divisions that halve a cell's genetic material in
the process of meiosis.
The scientists said it was clear that the new discovery is another
promising lead in the fast-moving RNA field.
(Source:Xinhua/ IANS News)