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.
G.S. van Doorn | EurekAlert!
A novel synthetic antibody enables conditional “protein knockdown” in vertebrates
20.08.2018 | Technische Universität Dresden
Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover
There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.
The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
20.08.2018 | Information Technology
20.08.2018 | Life Sciences
20.08.2018 | Information Technology