Thaindian News

London, Mar 3 (ANI): A new study finds that what really makes a man is his expression of the lone X chromosome and the activity of a protein complex that gives enzymes on the chromosome an extra boost to increase gene expression.

Men must increase gene expression on their lone X-chromosome to match the two X’s possessed by women. Gender is defined by that difference, but for men to live, the genetic imbalance must be remedied.

Brown University biologist Erica Larschan performed experiments in the convenient model of fruitflies to find out how men manage to do this.

Larschan, along with Eric Bishop, a graduate student at Harvard and Boston University, found that a protein complex called MSL that binds to the X-chromosome plays an important role in the process.

They found that MSL increases gene expression on the X-chromosome by cracking open the DNA double helix more frequently. For men, it’s a specialized drill bit.

Larschan and her colleagues measured how much of an enzyme called RNA polymerase II was active in the X-chromosome. They found that all chromosomes have the same amount of the enzyme, to a point.

The team showed that it was indeed MSL that allows more RNA polymerase II to move farther along the X-chromosome genes, past the point where those enzymes start to peter out on other chromosomes.

“People had thought for a long time that most of the regulation was happening at the beginning of a gene, so this is a new step that people are just starting to think about, which is regulating the entry of polymerase into the rest of the gene,” said Larschan.

“MSL is what’s promoting this entry into the gene bodies.”

The study appears in Nature. (ANI)