Recent research at the European Molecular Biology Laboratory (EMBL) reveals new insights into how cells achieve equality between the sexes.
A new link discovered between the membrane surrounding the nucleus and the male X-chromosome in fruit flies may play a crucial role in determining how active certain genes are.
The study, which appears in the current issue of the journal Molecular Cell, may help researchers understand how male and female cells manage to produce the same quantities of certain proteins.
"The problem arises because the females of many species from insects to humans have two X-chromosomes whereas males have only one", says Asifa Akhtar whose group carried out the project at EMBL. "Since genes contain the recipes for proteins this would normally lead female cells to produce twice as many of the proteins encoded by the X-chromosome as males. Balance is achieved through the activity of an assembly of proteins, called the dosage compensation complex (DCC)."
In flies the DCC hyperactivates the male X-chromosome to double the amount of proteins it produces. Investigating how this hyperactivation is brought about Akhtar's group discovered that the DCC interacts with molecules that sit in the nuclear membrane where they form gateways to the nucleus. This interaction seems to play an important role in dosage compensation, because when the pore proteins are removed from a cell the hyperactivity of the X-chromosome is lost.