First Frog Genome Sequenced
The Western clawed frog’s (Xenopus tropicalis) genome has been sequenced, making it the first amphibian to be added to the list of sequenced organisms. Scientists from several institutions collaborated on the study, which was led by Uffe Hellsten of the Department of Energy Joint Genome Institute and published in Science magazine.
The Western clawed frog was selected for the distinction because of its similarity to the African clawed frog (X. laevis), which has been a staple of research laboratories for decades. The Western clawed frog’s genome, however, is about half the size of its cousin’s, making studying it less time consuming and less expensive.
Some stretches of the Western clawed frog’s chromosomes are remarkably similar to comparable sections found in human and chicken chromosomes, and scientists found at least 1,700 genes related to human diseases, such as alcoholism, sudden infant death syndrome, acute myeloid leukemia and congenital muscular dystrophy. Researchers will be able to use the frog to study how these disease genes work.
The discovery may prove to be useful to frogs as well. Batrachochytrium dendrobatidis, a chytrid fungus that causes the disease chytridiomycosis, has devastated amphibian populations around the world. Researchers first identified the disease in 1998 in 50-year-old museum specimens of X. laevis. Frogs in the genus Xenopus appear to be immune to the disease, so studying the Western clawed frog’s genes will help scientists understand more about the disease and resistances to it.