Navigation Links
A new explanation for evolutionary changes in genetic sex-determination systems
Date:10/19/2007

In animals with separate sexes, embryos commit to becoming male or female at an early stage. Often this key decision is made by sex determination genes on the sex chromosomes. The genes involved in sexual development have changed remarkably little during evolution. In contrast, the sex determination genes and the sex chromosomes themselves are among the most rapidly changing features of the genome.

A research team formed by Sander van Doorn (Santa Fe Institute, USA) and Mark Kirkpatrick (University of Texas at Austin, USA) suggests an answer to the puzzle of why sex chromosomes evolve so rapidly. In a theoretical study published in the October 17, 2007 issue of NATURE they demonstrate that sexual conflict can establish novel sex-determining genes and sex chromosomes. The proposed mechanism extends the established theory on the origin of sex chromosomes, and it explains how sex determination can move from an ancestral sex chromosome to an autosome, a non-sex-chromosome, that then invades to become a new sex chromosome.

The mechanism suggested by these authors begins with an autosome that carries two genes with particular features. One of these two genes is under sexually antagonistic selection. This means that some versions of the gene (alleles) are more beneficial in males than in females, while other alleles are more beneficial for females. The other gene influences the sex of the individual. Natural selection produces an association between the two genes an allele that is most beneficial in males will occur most often with the allele of the other gene that makes the individual male. It is then possible that this new male-making, male-benefiting (or female-making, female-benefiting) combination of genes spreads through the population, eventually replacing the old pair of sex chromosomes.

Genes with sexually antagonistic fitness effects and mutations that influence sex determination appear to be common in nature, but how would we know if the model presented here actually caused a change in the sex-determination mechanism in a particular species" One possible test would look at sexually antagonistic genes on a chromosome immediately before and after that chromosome took over the role of sex determination. This might be possible by comparing closely related species with different sex chromosomes. One species would have a very young set of sex chromosomes, while the other would still use the old sex chromosomes, and might approximate the state of the chromosome right before the switch.


'/>"/>

Contact: G.S. van Doorn
vandoorn@santafe.edu
505-946-2786
Santa Fe Institute
Source:Eurekalert

Related biology news :

1. Simple explanation for complex pattern of feather development
2. Nobel Laureate finds elegant explanation for DNA transcribing enzymes high fidelity
3. Family trees of ancient bacteria reveal evolutionary moves
4. Revolutionary nanotechnology illuminates brain cells at work
5. The evolutionary triumph of flower power
6. Multi-species genome comparison sheds new light on evolutionary processes, cancer mutations
7. The first laugh: New study posits evolutionary origins of two distinct types of laughter
8. Getting an evolutionary handle on life after reproduction
9. Evolutionary conservation of a mechanism of longevity from worms to mammals
10. Finding rewrites the evolutionary history of the origin of potatoes
11. Evolutionary biology research techniques predict cancer
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/11/2017)... 2017 Research and Markets has announced the ... to their offering. ... eye tracking market to grow at a CAGR of 30.37% during ... Market 2017-2021, has been prepared based on an in-depth market analysis ... and its growth prospects over the coming years. The report also ...
(Date:4/5/2017)... , April 5, 2017  The Allen Institute ... Allen Cell Explorer: a one-of-a-kind portal and dynamic digital ... 3D imaging data, the first application of deep learning ... human stem cell lines and a growing suite of ... platform for these and future publicly available resources created ...
(Date:4/3/2017)... 2017  Data captured by IsoCode, IsoPlexis ... a statistically significant association between the potency ... and objective response of cancer patients post-treatment. ... whether cancer patients will respond to CAR-T ... as to improve both pre-infusion potency testing and ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... International research firm Parks Associates announced today that Tom ... 2017 Annual Meeting , October 11 in Scottsdale, Arizona ... and how smart safety and security products impact the competitive landscape. ... Parks Associates: Smart Home Devices: Main Purchase Driver ... "The residential security market has experienced continued growth, and ...
(Date:10/9/2017)... 2017  BioTech Holdings announced today identification and ... ProCell stem cell therapy prevents limb loss in ... demonstrated that treatment with ProCell resulted in more ... compared to standard bone marrow stem cell administration.  ... reduction of therapeutic effect.  ...
(Date:10/9/2017)... San Antonio, Texas (PRWEB) , ... ... ... a new study published on October 5, 2017, in the medical journal, ... demonstrated equivalence with the gold standard, video EEG, in detecting generalized tonic-clonic ...
(Date:10/6/2017)... ... October 06, 2017 , ... The HealthTech ... technology sector at their fourth annual Conference where founders, investors, innovative practitioners and ... the ELEVATE pitch competition showcasing early stage digital health and med tech companies. ...
Breaking Biology Technology: