Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sex hormone signature indicates gender rather than just chromosomes

18.10.2007
Help with assigning gender could one day be at hand for intersex individuals whose genital phenotypes and sex chromosomes don't match, thanks to the discovery of a stable sex hormone signature in our cells.

In an article published today in the online open access journal BMC Genomics, researchers have shown for the first time that testosterone leaves an irreversible molecular signature in cells that may provide a far more sophisticated way to look at sex than just ascertaining the presence of the Y chromosome. A team of researchers from the US and Germany were able to pinpoint the role of testosterone by comparing individuals with complete androgen insensitivity syndrome (CAIS) to people without CAIS. The findings provide a platform for future work that may lead to improved counselling for those whose gender is ambiguous.

Lead researcher, Professor Paul-Martin Holterhus, of University-Hospital Schleswig-Holstein, Kiel, Germany, said: "Androgens have long lasting effects during certain sensitive stages of our genital development and this is probably true for other organs". He adds "It is currently increasingly accepted that the brain shows sex-specific development in response to presence or absence of testosterone. This affects sex specific behaviour and probably modulates gender identity."

The role of androgens - especially the male-defining hormone testosterone - in sexual development has long been known. Gender programming begins in the embryo and is thought to continue throughout life, particularly during puberty. However, what's not currently known is the different roles of sex chromosome genes versus the long-term programming effects of sex hormones, namely androgens.

Individuals with CAIS, which affects 1 in 20,000 people, look like normal females. But at a genetic level CAIS women have XY sex chromosomes rather than the usual XX. The condition is due to mutations in the gene coding for the androgen receptor, which means that androgen signalling doesn't work: it essentially knocks out the effect of testosterone. The researchers used skin biopsies of external genitalia to compare the gene expression of normal males and CAIS females. Analysis revealed that between males and females, 440 genes differed in their level of transcription. The activity levels of these genes form a 'signature' that they used to evaluate partial androgen insensitivity syndrome (AIS) samples and could be developed to help understand more about individual AIS cases.

"Since we compared XY females with the XY males, the difference can only be explained by differences in androgen action and not by differences in sex chromosomes," explains Professor Holterhus. "Another intriguing observation is that the one normal female (with a 46,XX genotype) in our study did not differ a lot with respect to the identified genes from the XY females. This is an important reassurance for XY females because it limits the role of the sex chromosomes in gender assignment."

Charlotte Webber | alfa
Further information:
http://www.biomedcentral.com/bmcgenomics/

Further reports about: Androgen CAIS Chromosome Gender Sex Signature effect hormone testosterone

More articles from Life Sciences:

nachricht Newly designed molecule binds nitrogen
23.02.2018 | Julius-Maximilians-Universität Würzburg

nachricht Atomic Design by Water
23.02.2018 | Max-Planck-Institut für Eisenforschung GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>