Berkeley In a demonstration of "reverse-ecology," biologists at the University of California, Berkeley, have shown that one can determine an organism's adaptive traits by looking first at its genome and checking for variations across a population.
The study, to be published the week of Jan. 31 in the journal Proceedings of the National Academy of Sciences, offers a powerful new tool in evolutionary genetics research, one that could be used to help monitor the effects of climate change and habitat destruction.
The researchers scanned the genes of 48 different strains of Neurospora crassa, a type of red bread mold commonly used in genetics research. It is considered a model microbe because different strains can be mated and grown very quickly, and its growth occurs in a light-sensitive daily cycle that has been useful for studying circadian rhythms.
Yet for all its popularity in the lab, little was known about this fungus in its natural habitat, so the researchers specifically chose wild samples of the microbe from the Caribbean basin, South America and Africa. From this population-wide analysis, they found a striking pattern of variation in two regions of the genome that indicated the action of natural selection.
Within one of these regions, they found a gene that is known to be important to survival at cold temperatures, and posited that genes in the other region might play the same role. They then showed that members of the population that contained unique variants of their candidate cold-tolerant genes lived in regions with lower minimum temperatures up to 9 degrees Celsius on average and were able to grow better at cold temperatures than were strains found in more tropical climates.
The researchers also grew wild strains of Neurospora crassa in the lab alongside strains where the candidate cold-tolerant genes had been deleted from the genome, keeping all things the same except for th
|Contact: Sarah Yang|
University of California - Berkeley