Posts tagged ‘evolution’
Instead of sexes, fungi have mating types, which are distinguished by different variants of a few genes. However, some parts of plant or animal DNA that determine sex are similar to the parts of DNA in fungi that determine mating types. This makes fungi a useful model to study the evolutionary development of sex chromosomes.
Sex determination in the animal and plant kingdoms is believed to develop from the simpler system of mating types in fungi. In human, sex is determined by sex chromosomes, which the scientists think originated from a common “proto-sex chromosome” over 300 million years. This happened with inhibition of a step during the process of DNA replication, leading to two separate chromosomes. These two chromosomes then develop further over a long period of time.
A research group at Uppsala University identified the great similarities between the sex-determining parts of animal and plant genomes and the parts of fungi genome that determine mating types for the first time. Studying evolutionary development of sex chromosomes is difficult because there are many different sex-specific characters tied to them. This can now be overcome by using fungi as a simple organism model to study the origin of sex chromosomes.
Uppsala University (2008, March 18). Fungi Can Tell Us About The Origin Of Sex Chromosomes. ScienceDaily. Retrieved April 4, 2008, from http://www.sciencedaily.com /releases/2008/03/080317094851.htm