Biotech Updates

Genomic Archeology Reveals Early Evolution of Sex Chromosomes

May 27, 2011

Scientists from Uppsala University in Sweden are using genomics to trace the evolutionary history of sex chromosomes. H. Johannesson and colleagues discovered in their earlier studies that Neurospora tetrasperma, self-fertilizing fungus that has similar chromosomes with sexually reproducing organisms, has a region of suppressed recombination since less than six million years ago. This event preserved the genomic landscape because at normal conditions, the chromosomes recombine during mating. Their major discovery is that the suppressed recombination is accompanied by the loss of a number of preferred codons which are used by organisms to promote efficient and accurate protein synthesis.

"Our study furthers the understanding of factors driving mutational changes in genomes, which is a key issue in medical and natural science," says Johannesson. "For example, the onset of mutations, and the ability, or inability of organisms to eliminate them from their genome underlie key processes such as the onset of diseases in animals, and the rate of species extinctions. Our study advances the understanding of when and how young regions of suppressed recombination in sex regulating chromosomes accumulate mutations, and why evolution may fail to remove these harmful changes in an efficient manner," he added.