Our investigations are focused on 1) the characterization of plant retrotransposons and 2) DNA barcoding of the U.S. seed bank collection.  Retrotransposons are a class of repetitive genetic elements embedded in the genomes of their hosts.  They are the most abundant kind of DNA in the genomes of virtually all plants and animals.  In many plants and some animals, including humans, they constitute more than 80% of chromosomal DNA.  They are capable of self-replication and utilize the enzyme reverse transcriptase to sponsor the replication of their small genomes.  Unlike their retrovirus cousins, they are non-infectious and are transmitted from one generation to the next through the germ-line.  Once considered by many molecular geneticists to be pesky genetic parasites and dubbed "selfish DNA", they are now considered to play major roles in chromosome transmission, gene expression, mutation, epigenetic regulation, genome rearrangement, and the evolution of species.  They may more appropriately be called evolution-inducing symbionts.

We are cataloging their distribution and studying how they impact on the evolution of plants and plant genomes.  We are also focused on determining the function of a gene found in several plant retrotransposon families that resembles the envelope protein found in mammalian viruses, including retroviruses like HIV.  

On an unrelated project, we are collaborating with the U.S. Department of Agriculture in their efforts to confirm the species identification of their massive legume seed repository using DNA barcoding technology. 

We are using both experimental and bioinformatics approaches to explore these questions in the genomes of legumes, specifically soybean and clover.