This fungus has over 17,000 sexes!

Trichaptum is a woody plate mushroom that usually grows on trees and logging in cooler regions of the Northern Hemisphere

In total, the scientists collected 180 specimens from three Trichaptum species; some collected by themselves, while others were sent (by regular mail) from colleagues around the world

Previous research has shown that the sex of these mushrooms is controlled by two regions in the genome, MATA and MATB, each with many different possible alleles

This diversity hinders sequencing efforts

See " Fungi squeezed through microchannels provides clues to cell growth "

Now, however, the reduced cost of next-generation technologies makes it possible to sequence so many individuals

Why any organism needs so much sexual variation remains an open question, and it may be related to the mushroom's consolidating life>

Plus, having so many variants to choose from makes any given neighbor more likely to be sexually compatible — up to a 98 percent chance, which could help the species' long-term survival

Duur Aanen, an evolutionary biologist at Wageningen University in the Netherlands, said the study is a good example of balanced selection, a phenomenon in which evolutionary preferences for rare alleles lead to higher levels of heterozygosity, He is considering using it in his population genetics course

However, Aanen, who was not involved in the study, also noted that there is one big question that none of the scientists working on the system can fully answer: While diversity might help, why push it to such an extreme? "If you have 100 Alleles, you already have quite a bit of compatibility," Aanen said