The Beck lab uses genomics, bioinformatics and molecular biological techniques to investigate the ways in which repetitive DNA elements, such as transposons, affect human genomes.
Our Research Focus
The mechanisms governing non-recurrent human structural variation (SV) are diverse and often poorly understood. I am investigating how human DNA maintains fidelity in the context of a repetitive genome. Human Alu elements number over one million copies per human genome, and recent studies have found that these repeat sequences often mediate SVs in some loci. Through computational, molecular biological and genomic techniques, we will identify regions susceptible to this form of SV and investigate the enzymes that limit or promote Alu-mediated rearrangements. These lines of inquiry could find regions prone to instability in human cancers and lead to targets for therapy.
Highly active (i.e., "hot") long interspersed element-1 (LINE-1 or L1) sequences comprise the bulk of retrotransposition activity in the human genome; however, the abundance of hot L1s in the human population remains largely unexplored. Here, we used a fosmid-based, paired-end DNA sequencing strategy to identify 68 full-length L1s that are differentially present among individuals but are absent from the human genome reference sequence. The majority of these L1s were highly active in a cultured cell retrotransposition assay. Genotyping 26 elements revealed that two L1s are only found in Africa and that two more are absent from the H952 subset of the Human Genome Diversity Panel. Therefore, these results suggest that hot L1s are more abundant in the human population than previously appreciated, and that ongoing L1 retrotransposition continues to be a major source of interindividual genetic variation.