Computer Science Department Seminar

11:30AM-12:30PM, Wednesday, December 1, 2010

Prof. Justin DiAngelo, Hofstra University

Title: Genomes, Heterochromatin and the Dot Chromosome: Comparative Genomics in Drosophila


In all eukaryotic cells, the genetic material is packaged into a structure called chromatin. There are two major types of chromatin: euchromatin, which is usually found in gene-rich areas of the genome and is associated with active gene expression and heterochromatin, which is thought to be found in gene-poor areas and around genes that are not being expressed. The fourth chromosome of the fruit fly, Drosophila melanogaster (also known as the dot chromosome), is unusual in that it has many characteristics of heterochromatin, although the gene density is similar to that found on other euchromatic chromosomes. Interestingly, the dot chromosome of Drosophila virilis, a species that diverged from Drosophila melanogaster about 40-60 million years ago, is largely euchromatic, even though it is similar in size to the D. melanogaster dot chromosome and contains some of the same genes. Therefore, to understand why these chromosomes have different chromatin structures, we are taking a comparative genomics approach to identify the genetic elements (i.e., intact genes, nucleotide repeat regions, repetitive elements, etc.) found on the dot chromosomes of different species of Drosophila. To do this, we have joined the Genomics Education Partnership, a consortium that consists of faculty and students at primarily undergraduate institutions, including Hofstra University. GEP undergraduates have improved the accuracy of more than 2.4 million bases of draft genomic sequence from several species of Drosophila and have produced hundreds of gene models using evidence-based manual annotation. These analyses have led us to conclude that specific genetic elements play a role in controlling overall chromatin packaging and can give us insight into evolution of these species at the molecular level.


Dr. DiAngelo received his B.S. in Biological Sciences from the University of Delaware and his Ph.D. in Cell and Molecular Biology from the University of Pennsylvania. He then went on to do postdoctoral research in the Department of Neuroscience at the University of Pennsylvania. This is his first year as an Assistant Professor in the Department of Biology at Hofstra. In addition to being involved in comparative genomics research, Dr. DiAngelo is also interested in understanding how fat storage is regulated using Drosophila as a model system.

For more information about this colloquium, please contact Habib M. Ammari at