At least in mice (and probably some day in humans) it is possible to separately tweak the expression of individual genes that are influenced by testosterone and estrogen.
Now a team of scientists at the University of California, San Francisco (UCSF) has uncovered many genes influenced by the male and female sex hormones testosterone and estrogen that, in turn, govern several specific types of male and female behaviors in mice.
Imagine being able to create humans who have very rare combinations of both female and male traits. That'll be possible eventually. Some prospective parents will opt to do it for a variety of reasons.
While testosterone and estrogen act to turn on and off groups of genes these scientists turned off individual genes from these groups to see what affect each gene's suppression caused.
The UCSF team selectively turned many of these genes off one by one and found they could manipulate individual behaviors in the mice, like their sex drive, desire to pick fights, or willingness to spend extra time caring for their young.
"It's as if you can deconstruct a social behavior into genetic components," said Nirao Shah, MD, PhD, an associate professor in the Department of Anatomy at UCSF who led the research, which is published in the 2/3/12 issue of the journal Cell. "Each gene regulates a few components of a behavior without affecting other aspects of male and female behavior.
Obviously this sort of experiment would be hard to do in humans for both ethical and practical reasons. While the ethical objections are obvious enough the practical obstacles are also quite high. Just carrying out an experiment by turning off individual genes at conception would require many experimental subjects as well as many years of waiting to see how each tweak changes cognitive processes and behavior.
But with humans lots of experiments happen naturally due to genetic mutations during fetal development or before. It is possible that with really cheap DNA sequencing scientists may be able to identify humans who already have mutations that turn off or at least turn down the expression of some of the genes that the UCSF researchers are studying in lab mice.
|Share |||Randall Parker, 2012 February 05 11:29 PM Brain Sex Differences|