Epigenetics helps explain early-onset puberty in females

January 29, 2013

New research from Oregon Health & Science University has provided significant insight into the reasons why early-onset puberty occurs in females. The research, which was conducted at OHSU's Oregon National Primate Research Center, is published in the current early online edition of the journal Nature Neuroscience.

The paper explains how OHSU scientists are investigating the role of epigenetics in the control of . Epigenetics refers to changes in gene activity linked to external factors that do not involve changes to the genetic code itself. The OHSU scientists believe improved understanding of these complex protein/gene interactions will lead to greater understanding of both early-onset (precocious) puberty and delayed puberty, and highlight new therapy avenues.

To conduct this research, scientists studied female rats, which like their human counterparts, go through puberty as part of their early aging process. These studies revealed that a group of proteins, called PcG proteins, regulate the activity of a gene called the Kiss1 gene, which is required for puberty to occur. When these PcG proteins diminish, Kiss1 is activated and puberty begins.

PcG proteins are produced by another set of genes that act as a biological switch during the embryonic stage of life. The role of these proteins is to turn off specific downstream genes at key developmental stages.

OHSU scientists found that both the activity of these "master" genes and their ability to turn off puberty are impacted by two forms of epigenetic control: a chemical modification of DNA known as DNA methylation, and changes in the composition of histones, a specialized set of proteins that modify gene activity by interacting with DNA.

Using this new information, researchers were then able to delay puberty in female rats. They accomplished this by increasing PcG protein levels in the hypothalamus of the brain using a targeted gene therapy approach so that Kiss1 activation failed to occur at the normal time in life. The hypothalamus is a region of the brain that controls reproductive development.

"While it was always understood that an organism's genes determine the timing of puberty, the role of in this process has never been recorded until now," said Alejandro Lomniczi, Ph.D., a scientist in the Division of Neuroscience at the OHSU Oregon National Primate Research Center.

"Because epigenetic changes are driven by environmental, metabolic and cell-to-cell influences, these findings raise the possibility that a significant percentage of precocious and delayed puberty cases occurring in humans may be the result of environmental factors and other alterations in epigenetic control," said Sergio Ojeda, D.V.M, who is also a scientist in the Division of Neuroscience at the OHSU ONPRC.

"There is also much more to be learned about the way that epigenetic factors may link environmental factors such as nutrition, man-made chemicals, social interactions and other day-today influences to the timing and completion of normal puberty."

Explore further: Exposure to environmental chemicals in the womb reprograms the rodent brain to disrupt reproduction

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1 / 5 (14) Jan 29, 2013
Using this new information, researchers were then able to delay puberty in female rats.
Sounds like theyre looking for population control and life-extending strategies. Our reproductive equipment is what ages us. Without these troublesome appendages and hormones we could live many more decades.

We would be less preoccupied, more focussed, less violent and irrational. This is an eventuality. Reproduction WILL be externalized and strictly controlled, as many of the people who bear children cannot be trusted with responsibility for what might be considered the most important function of the species.

Once this occurs then people will start to discard those components which age them and waste their time.
4 / 5 (1) Jan 29, 2013
I wonder if alternatively early onset puberty might ultimately come down to our bodies reacting to stresses/changes in our society as well as physical environment. There should be an evolutionary advantage to having children earlier in times of stress. It could be triggered by something as simple as over stimulation of the brain at an early age mimicking survival stresses and activate epigenetic control mechanisms. Changes in society along with other environmental concerns such as the hormone like chemicals leached from some plastics and from pesticide residues could account for the triggers; maybe requiring several factors to act in concert. These are new circumstances that humans have not had to cope with before.
2.8 / 5 (25) Jan 29, 2013
Genitals getting pesky again, Otto?

Go Ducks!
1 / 5 (10) Jan 30, 2013
Hello lying stalking bug
Genitals getting pesky again, Otto?

Go Ducks!
Well I'm certainly not preoccupied with them the way you are eh? It's all you seem to talk about.

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