Life Science and Medical News from Around the Globe
Scientists in Japan Study Evolution of Fruit Flies Adapted to Life Without Light; Candidate Genes for Dark Adaptation in Drosophila Include Genes for Chemical Receptors, Pheromone Synthesis, Smell Memories, and Circadian Rhythms
On November 11, 1954, Dr. Syuiti Mori turned out the lights on a small group of fruit flies. More than sixty years later, the descendents of those flies have adapted to life without light. The flies, a Drosophila melanogaster variety now known as "Dark-fly,” out-compete their light-loving wild-type cousins when they live together in constant darkness, according to research reported in the February 2016 issue of the open-access journal G3: Genes|Genomes|Genetics, published by the Genetics Society of America. This competitive difference allowed the researchers to re-play the evolution of Dark-Fly and identify the genomic regions that contribute to its success in the dark. The G3 article is titled “Dynamics of Dark-Fly Genome Under Environmental Selections” and it served as the cover story of the February issue of the journal. "We hope understanding the genetics behind Dark-Fly's adaptations will shed light on how genes are selected during rapid evolution," says study leader Naoyuki Fuse, Ph.D., of Kyoto University in Japan. The Dark-Fly project is the longest-running example of an experimental evolution study where scientists follow a population over many generations. It is also the first to analyze genome evolution in a multi-cellular organism adapted to a defined condition in the lab. The project was initiated by Dr. Mori as part of a series of experiments investigating how the traits of fruit flies are altered in response to changes in their environment. The fruit fly Drosophila melanogaster is a heavily studied model organism often used to examine genetic changes during evolution. To keep the flies away from light, they are reared in vials kept in a large pot painted black on the inside and covered with a blackout cloth.