Rainbow trout genome shows how genetic material evolved

About 100 million years ago, the genome of the rainbow trout (Oncorhynchus mykiss) duplicated itself. Since then, about half of the duplicated protein-coding genes have been lost, but nearly all of the original and duplicate genes that control how genes are expressed still exist, researchers report April 22 in Nature Communications.

The finding challenges the idea that whole genome duplications are followed by quick, massive reorganization and deletions of genetic material. Instead, the gene editing process is slower and more methodical, a discovery that could have implications for understanding how vertebrates evolved, the scientists say.