During prenatal development, the brains of most animals, including humans, develop specifically male or female characteristics. New research sheds light on how this process is triggered.
In the study, published in the journal Nature Neuroscience , Margaret McCarthy from the University of Maryland and colleagues studied brain development in newborn rats.
She found that giving estradiol, a testosterone derivative, triggers a mechanism by which certain genes in the brain are “unsilenced”, allowing them to initiate the process of masculinisation.
This process involves a group of enzymes known as DNA methyltransferases, or Dnmts, which modify DNA to repress gene expression.
The researchers also found that by inhibiting Dnmts, they could alter the reproductive behaviour of male and female mice.
In every species that has been studied, including humans, the POA plays a key role in governing male sexual behaviour.
The injections occurred after the first week of birth, the time when the window for brain sexual differentiation was thought to have been closed.
Despite this, the preoptic area in these animals was transformed, and took on structural characteristics of a male rat. — IANS
