Researchers Generate Whole-Genome Map of Fruit Fly Genetic Recombination

Meiosis is the process of cell division that gives rise to reproductive cells. During this process, chromosomes are copied and paired up to swap bits of their DNA before being separated to create eggs and sperm.

This process, called recombination, is an important driving force behind genetic variability and evolution, but most importantly, it ensures that chromosomes move properly during the subsequent divisions that form these eggs and sperm. When the recombination doesn’t go smoothly, it can cause a number of problems in humans, including miscarriages and birth defects.

For the first time, Stowers researchers in the Hawley Lab have mapped where recombination occurs across the whole genome of the fruit fly Drosophila melanogaster after a single round of meiosis. Their results indicate that separate mechanisms position the two main kinds of recombination events, crossovers and noncrossovers.

The Stowers researchers wanted to determine how both crossovers and noncrossovers are distributed across the chromosomes of fruit flies. Crossovers are relatively easy to identify because they involve large sections of chromosomes that encompass thousands of base pairs, the A’s, C’s, T’s, and G’s that make up DNA. But noncrossovers are tougher to spot, because they only involve a few hundred of those letters. So, Danny Miller, an MD-PhD student at the University of Kansas Medical Center who conducted his doctoral research in the Hawley lab, had to rely on whole genome sequencing and new computer algorithms to pinpoint the locations of both kinds of events.

“It is amazing to me that more than 100 years after the discovery of genetic recombination in flies, we are only starting to understand just how these events are distributed,” says Investigator Scott Hawley, PhD.

This research was published in the May 2016 issue of the journal Genetics.