Navigation Links
Study finds epigenetics, not genetics, underlies homosexuality
Date:12/11/2012

KNOXVILLE Epigenetics how gene expression is regulated by temporary switches, called epi-marks appears to be a critical and overlooked factor contributing to the long-standing puzzle of why homosexuality occurs.

According to the study, published online today in The Quarterly Review of Biology, sex-specific epi-marks, which normally do not pass between generations and are thus "erased," can lead to homosexuality when they escape erasure and are transmitted from father to daughter or mother to son.

From an evolutionary standpoint, homosexuality is a trait that would not be expected to develop and persist in the face of Darwinian natural selection. Homosexuality is nevertheless common for men and women in most cultures. Previous studies have shown that homosexuality runs in families, leading most researchers to presume a genetic underpinning of sexual preference. However, no major gene for homosexuality has been found despite numerous studies searching for a genetic connection.

In the current study, researchers from the Working Group on Intragenomic Conflict at the National Institute for Mathematical and Biological Synthesis (NIMBioS) integrated evolutionary theory with recent advances in the molecular regulation of gene expression and androgen-dependent sexual development to produce a biological and mathematical model that delineates the role of epigenetics in homosexuality.

Epi-marks constitute an extra layer of information attached to our genes' backbones that regulates their expression. While genes hold the instructions, epi-marks direct how those instructions are carried out when, where and how much a gene is expressed during development. Epi-marks are usually produced anew each generation, but recent evidence demonstrates that they sometimes carryover between generations and thus can contribute to similarity among relatives, resembling the effect of shared genes.

Sex-specific epi-marks produced in early fetal development protect each sex from the substantial natural variation in testosterone that occurs during later fetal development. Sex-specific epi-marks stop girl fetuses from being masculinized when they experience atypically high testosterone, and vice versa for boy fetuses. Different epi-marks protect different sex-specific traits from being masculinized or feminized some affect the genitals, others sexual identity, and yet others affect sexual partner preference. However, when these epi-marks are transmitted across generations from fathers to daughters or mothers to sons, they may cause reversed effects, such as the feminization of some traits in sons, such as sexual preference, and similarly a partial masculinization of daughters.

The study solves the evolutionary riddle of homosexuality, finding that "sexually antagonistic" epi-marks, which normally protect parents from natural variation in sex hormone levels during fetal development, sometimes carryover across generations and cause homosexuality in opposite-sex offspring. The mathematical modeling demonstrates that genes coding for these epi-marks can easily spread in the population because they always increase the fitness of the parent but only rarely escape erasure and reduce fitness in offspring.

"Transmission of sexually antagonistic epi-marks between generations is the most plausible evolutionary mechanism of the phenomenon of human homosexuality," said the study's co-author Sergey Gavrilets, NIMBioS' associate director for scientific activities and a professor at the University of Tennessee-Knoxville.


'/>"/>

Contact: Catherine Crawley
ccrawley@nimbios.org
865-974-9350
National Institute for Mathematical and Biological Synthesis (NIMBioS)
Source:Eurekalert

Related biology news :

1. UCI radiology researcher to aid NASA bone density study
2. German Research Foundation to fund globally unique twin study on social inequality
3. OHSU study shows that a molecule critical to nerve cells increases drammatically during hypertension
4. Numerical study suggests subsea injection of chemicals didnt prevent oil from rising to sea surface
5. New study reveals lions are rapidly losing ground in Africa
6. Study finds prioritizing rather than canvassing entire plant genome may lead to improved crops
7. New study shows how copper restricts the spread of global antibiotic-resistant infections
8. New study shows probiotics help fish grow up faster and healthier
9. Study IDs kerosene lamps as big source of black carbon
10. New study shows how climate change could affect entire forest ecosystems
11. Fracking in Michigan: U-M researchers study potential impact on health, environment, economy
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/3/2017)... April 3, 2017  Data captured by ... platform, detected a statistically significant association between ... to treatment and objective response of cancer ... to predict whether cancer patients will respond ... as well as to improve both pre-infusion potency ...
(Date:3/30/2017)... The research team of The Hong Kong Polytechnic University (PolyU) ... ground breaking 3D fingerprint minutiae recovery and matching technology, pushing contactless ... use in identification, crime investigation, immigration control, security of access and ... ... A research team led by Dr Ajay Kumar ...
(Date:3/29/2017)... 29, 2017  higi, the health IT company that ... North America , today announced a Series B ... of EveryMove. The new investment and acquisition accelerates higi,s ... to transform population health activities through the collection and ... higi collects and secures data today on behalf ...
Breaking Biology News(10 mins):
(Date:5/23/2017)... ... May 23, 2017 , ... Energetiq Technology, a world ... facility expansion to accommodate its rapid growth. , The renovations at the company’s ... of the existing areas. The expansion includes, a state-of-the-art engineering facility, and a ...
(Date:5/23/2017)... ... May 23, 2017 , ... Customers often prefer PLC ... and again. METTLER TOLEDO has released two new videos that show how they ... of the ACT350 into Siemens and Allen Bradley PLCs is easy and fast. ...
(Date:5/21/2017)... , ... May 19, 2017 , ... ... and educational conference of the American Association of Bioanalysts (AAB) and the College ... in Houston. The conference reinforces AAB’s commitment to excellence in clinical laboratory services ...
(Date:5/18/2017)... Mass. (PRWEB) , ... May 18, 2017 , ... ... the procedure on April 28, 2017 at the Prince Of Wales Private Hospital. ... cervical disc at level C6-C7. The patient failed conservative treatments prior to undergoing ...
Breaking Biology Technology: