Heterochromatin variation in Drosophila



Dr. Daniel Barbash; Cornell University

November 3 in the Fralin Auditorium, Fralin Hall 102

Hosted by Dr. Igor Sharakhov



Higher eukaryotes contain enormous amounts of repetitive DNA, comprised of transposable elements and tandemly repeated satellite DNA, that are typically found in heterochromatic regions of the genome.  Much debate has centered around trying to determine whether these repeats are functional, parasitic, or merely junk.  Repetitive DNAs are challenging to sequence and to bioinformatically characterize and assemble, and are thus often under-represented or even absent from so-called high-quality finished genomes.  I will first present new methods that we have developed to characterize repeat-sequence variation from large samples of Drosophila populations.  From this work, we have discovered that the content of simple-satellite DNAs (with monomers <=20 bp) is much more variable among species than previously thought.  We have also found that double insertions of transposable elements are a likely source of new complex satellites.  I will then present ongoing efforts to test whether heterochromatin variation causes non-Mendelian segregation of chromosomes, in a process termed meiotic drive.  We have developed a method to detect meiotic drive by sequencing large pools of progeny derived from heterozygous females, and used it to discover several promising new candidates for meiotic drive.

A Pooled Sequencing Approach Identifies a Candidat.pdf A Pooled Sequencing Approach Identifies a Candidate Meiotic Driver in Drosophila
Correlated variation and population differentiatio.pdf Correlated variation and population differentiation in satellite DNA abundance among lines of Drosophila melanogaster

This seminar will NOT be livestreamed.

Barbash Flyer