Navigation Links
A new explanation for evolutionary changes in genetic sex-determination systems

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
Santa Fe Institute

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:
(Date:10/5/2015)... 5, 2015 ) ... NXT-ID, Inc. (NASDAQ: NXTD ), a biometric authentication ... --> ) releases the following ... NXTD ), a biometric authentication company focused on the ... Group ( ) releases the following ...
(Date:9/30/2015)... -- The global glucose monitoring device and diabetes management market is ... report on the industry from Kalorama Information. Sales in the traditional ... by continuous glucose monitoring and sensor segment, according to the ... products in its latest report, The Global Glucose Monitoring ... , ...
(Date:9/28/2015)... -- The global image sensors market ... by 2020, growing at a CAGR of 4.6% from ... (BSI) technique to improve picture quality are expected to ...      (Logo: , The light falls ... and, thus, reduce the noise interference and increase picture ...
Breaking Biology News(10 mins):
(Date:10/12/2015)... Calif. and BRUSSELS , Oct. ... (Euronext Brussels: UCB) today presented additional findings from an exploratory ... The findings were presented today in an oral plenary ... (ASBMR) 2015 Annual Meeting in Seattle . ... --> The small exploratory sub-study data showed ...
(Date:10/12/2015)... Oct. 12, 2015 This report covers the ... cell type, products, applications, end-user markets and geographic segmentation. ... The global cell expansion market generated revenue of ... reach revenues of $9.7 billion in 2015 and $22.0 ... (CAGR) of 17.8% from 2015 to 2020. This ...
(Date:10/12/2015)... ANNAPOLIS, Maryland , 12 de octubre de 2015 ... O. Matsui (D-CA) llegó a un récord en el ... tercera edición anual de la International Plasma Awareness Week ... octubre. La IPAW está patrocinada por la Plasma ... estando diseñada para: , Aumentar la ...
(Date:10/12/2015)... 12, 2015 LabStyle Innovations Corp. ... Solution, today announced its Medical Director, Dr. Moshe ... MobiHealth,s 5th EAI International Conference on Wireless Mobile ... innovations in mobile and wireless technologies," the conference will ... from October 14 - 16, 2015. The conference is ...
Breaking Biology Technology: