Meiotic Recombination

Meiotic recombination is a fundamental biological process that plays a central role in evolution and plant breeding due to its ability to generate the genetic diversity upon which the selection can act. Meiotic recombination frequency is not constant in a genome. There are recombinantly hyperactive “hot spots” and inert “cold spots” relative to the genome average. To reveal the control mechanism behind the meiotic recombination distribution in plants, we use the cloned 140-kb a1-sh2 interval as a model to study the meiotic recombination in the maize genome. Our hypotheses are that recombination breakpoints cluster in the hot spots that are genes or unique intergenic regions associated with genes and that recombination rate and breakpoint distribution pattern are influenced by cis- and trans-acting genetic factors. To test these hypotheses we are continuing physical and genetic study of the a1-sh2 interval to identify and characterize all the hot spots within it. In addition, we are using unique maize stocks to identify and characterize the cis- and trans-effects on recombination across the a1-sh2 interval. In addition, a reverse genetic approach is being used to characterize several maize genes predicted to be involved in recombination.

Project Abstract at USDA