Mathematical Biology Seminar

 Mariel Vazquez
UC Berkeley
"Using graph theory to analyze chromosome aberrations "
Wednesday February 16, 2005
3:05pm in LCB 121
Chromosome aberrations (large-scale genome rearrangements) result from double-stranded DNA breakage and misrejoining in a cell. We have developed a mathematical framework, related to the well-explored theory of cubic (i.e. 3-regular) multigraphs, for characterizing chromosome aberrations, including complex ones involving 3, 4 or more breaks in reactions not reducible to a sequence of simpler reactions each one of which involves fewer breaks. A genome rearrangement multigraph" specifies not only breakpoints and misrejoinings but also the way in which one or more chromosomes are involved.

Radiation cytogenetics is concerned with rearrangements of the genome caused by ionizing-radiation, especially with chromosome aberrations observed at the first mitosis after irradiation. I will discuss how radiation-induced chromosome aberrations can be described, classified and analyzed using aberration multigraphs. Furthermore, aberration multigraphs facilitate using cytogenetic data to characterize mechanisms of DNA repair and misrepair. If time permits I will also discuss possible applications of our work to comparative genomics (modern studies of comparative genetics in evolution analyze large-scale genome rearrangements between species).