Newly Discovered Gene Enables Fish to 'Disappear'

Researchers at Vanderbilt discovered that the agouti gene family has a new member called AgRP2 that enables fish to change colors to match their surroundings. The two other genes in this family are the agouti protein and the agouti-related protein (AgRP). The agouti protein inhibits the melanocortin-1 receptor in the pigment cells of the body from producing dark pigments, which causes it to produce red-yellow pigments instead. This phenomenon can be seen in mammals when the seasons change. It also plays a major role in hair and skin color. AgRP has a similar effect on the melanocortin-4 receptor in the brain. This receptor is responsible for inhibition of food intake, so when AgRP blocks it, the brain sends signals to the body that stimulates the drive for eating. This may be an important cause for obesity (although I blame all the fast food restaurants). The new gene that these researchers discovered, AgRP2, regulates the expression on pmch and pmchl, two prohormone genes that are precursors to melanin-concentrating hormone. This causes pigments to lighten and has been proven to be the gene responsible to aid fish in "camouflaging" themselves with their surroundings.

I found this article particularly interesting because my dad is in the fish selling business. Also, I think it is very interesting that this one gene family can control so many different aspects of the mammal or fish.

Rachel Anthony

VTPP 434-501

http://www.sciencedaily.com/releases/2010/10/101029132928.htm