The Sum of Your Experiences
09/09/13 15:42 Filed in: GenomeWeb Daily Scan
Submitted by S. Pelech - Kinexus on Mon, 09/09/2013 - 17:50
While the lengthy article by David Dobbs provides many examples of environmental conditions altering gene expresssion patterns in humans and other animals, it focuses much too heavily on gene expression and epigenomics at the root of changes in perception and behaviour. In fact, the word "protein" does not even show up once in the piece. The reality is that behaviour in response to environment input will be altered through a myriad of interconnected mechanisms in addition to genetic changes and at vastly different time scales. Rapid responses can bypass gene regulation completely with post-translational regulation of proteins, for one example, by reversible protein phosphorylation, or through allosteric modulation by extracellular mediators like adrenaline and intracellular second messengers like cyclic-AMP. Very longer term responses may be forged by the formation of new dendritic connections between the ~75 billion neurons in the typical human brain. Alteration in the expression of genes in cells is just one of many ways that the molecular and cellular intelligence systems of organisms adjust to their environments.
One of the more striking examples of how an organism can undergo dramatic mental and physical changes from environmental stress is the case of the domesticated pig that escapes and goes wild. In a matter of months, the feral pig will grow hair and tusks, gain weight, and develop a highly aggressive attitude with a voracious appetite to eat almost anything. Its head becomes extended and narrower with a longer snout, and its legs will also grow longer. Presumably increased levels of adrenaline and other stress hormones can initiate such gross changes that include altered gene expression. Such phenotypic plasticity arises in many plants and animals.
While the conversion of domestic pigs into wild boars can occur so rapidly, it would be fascinating to see how reversible this could be with captured feral pigs. Alas, this would be a rather difficult feat with no obvious commercial benefit as nearly a trillion well behaved pigs are already safely in captivity globally.
Link to the original blog post
While the lengthy article by David Dobbs provides many examples of environmental conditions altering gene expresssion patterns in humans and other animals, it focuses much too heavily on gene expression and epigenomics at the root of changes in perception and behaviour. In fact, the word "protein" does not even show up once in the piece. The reality is that behaviour in response to environment input will be altered through a myriad of interconnected mechanisms in addition to genetic changes and at vastly different time scales. Rapid responses can bypass gene regulation completely with post-translational regulation of proteins, for one example, by reversible protein phosphorylation, or through allosteric modulation by extracellular mediators like adrenaline and intracellular second messengers like cyclic-AMP. Very longer term responses may be forged by the formation of new dendritic connections between the ~75 billion neurons in the typical human brain. Alteration in the expression of genes in cells is just one of many ways that the molecular and cellular intelligence systems of organisms adjust to their environments.
One of the more striking examples of how an organism can undergo dramatic mental and physical changes from environmental stress is the case of the domesticated pig that escapes and goes wild. In a matter of months, the feral pig will grow hair and tusks, gain weight, and develop a highly aggressive attitude with a voracious appetite to eat almost anything. Its head becomes extended and narrower with a longer snout, and its legs will also grow longer. Presumably increased levels of adrenaline and other stress hormones can initiate such gross changes that include altered gene expression. Such phenotypic plasticity arises in many plants and animals.
While the conversion of domestic pigs into wild boars can occur so rapidly, it would be fascinating to see how reversible this could be with captured feral pigs. Alas, this would be a rather difficult feat with no obvious commercial benefit as nearly a trillion well behaved pigs are already safely in captivity globally.
Link to the original blog post