Exposure to stress even before conception causes genetic changes to offspring

A female's exposure to distress even before she conceives causes changes in the expression of a gene linked to the stress mechanism in the body—in the ovum and later in the brains of the offspring from when they are born, according to a new study on rats conducted by the University of Haifa.

"The systemic similarity in many instances between us and mice raises questions about the transgenerational influences in humans as well, for example, the effects of the Second Lebanon War or the security situation in the South on the children of those who went through those difficult experiences," the researchers said. "If until now we saw evidence only of behavioral effects, now we've found proof of effects at the ."

In previous studies in Prof. Micah Leshem's lab, it was found that exposing rats to stress before they had even conceived (and even at their "teen" stage) influences the behavior of their offspring. This study, conducted in the lab of Dr. Inna Gaisler-Salomon by PhD student Hiba Zaidan, in cooperation with Prof. Leshem, the researchers sought to examine whether there was an influence on .

In the study, which was recently published in the journal Biological Psychiatry, the researchers focused on the gene known as CRF-1, a gene linked to the body's stress-control system that expresses itself in many places in the brain under stress.

The researchers took female rats that were 45 days old, which is parallel to human adolescence. Some of the rats were exposed to "minor" stress, which included changes in temperature and daily routine for seven days, and compared them to a that was not exposed to stress at all. The rats were mated and conceived two weeks later.

In the first part of the study, the researchers examined the ova of the rats that were exposed to stress even before they conceived, and they found that at that stage there was enhanced expression of the CRF-1 gene. For the second part, the researchers examined the brains of newborn rats immediately after birth, before the mother could have any influence on them, and found that even at the neonatal stage, there was enhanced expression of the CRF-1 gene in the brains of the rats born to mothers who had been exposed to stress.

During the third stage, the researchers exposed the offspring – both those whose mothers had been exposed to stress and those whose mothers were not – to stress when they reached adulthood. It emerged that the expression of CRF-1 among the offspring was dependent on three factors: The sex of the offspring, the stress undergone by the mother and the stress to which the were exposed. The whose mothers had been exposed to stress and who themselves underwent a "stressful" behavioral test showed higher levels of CRF-1 than other groups.

"This is the first time that we showed that the genetic response to stress in is linked to the experiences their mothers underwent long before they even got pregnant with them," the researchers said. "We are learning more and more about intergenerational genetic transfer and in light of the findings, and in light of the fact that in today's reality many women are exposed to even before they get pregnant, it's important to research the degree to which such phenomenon take place in humans."

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alq131
5 / 5 (1) Jul 08, 2013
how is this different from the article published in 2011 from the journal of Developmental Psychobiology? Is seems that both are claiming this is the first time this connection has been shown but is this new from 2011 or just a republication in a new journal?
JVK
1.7 / 5 (3) Jul 09, 2013
In my model, nutrient stress and social stress act transgenerationally via the same conserved molecular mechanisms in species from microbes to man. Those who claim 'firsts' might first want to see our section on molecular epigenetics in a 1996 Hormones and Behavior review article: From Fertilization to Adult Sexual Behavior http://www.hawaii...ion.html

That review led to a series of presentations and published works that culminated with Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors (2012) and to Nutrient-dependent/pheromone-controlled adaptive evolution: a model (2013) which was published on June 14 in the same open-access journal: http://www.socioa...ew/20553

"New scientific ideas never spring from a communal body, however organized, but rather from the head of an individually inspired researcher..." -- Max Planck
JVK
1.7 / 5 (3) Jul 09, 2013
In my model, nutrient stress and social stress act transgenerationally via the same conserved molecular mechanisms in species from microbes to man. Those who claim 'firsts' might first want to see our section on molecular epigenetics in a 1996 Hormones and Behavior review article: From Fertilization to Adult Sexual Behavior http://www.hawaii...ion.html