Meoisis: Pairing and Patterning
Pairing. How do homologous chromosomes recognize one another and become juxtaposed in space? We have previously identified both recombination-mediated and recombination-independent mechanisms. We now probe these processes in budding yeast using 3D timelapse fluorescence spot detection over long timescales to define detailed dynamics and functional requirements.
Crossover Patterning. Crossover sites are evenly-spaced along the chromosomes, a manifestation of the classical phenomenon of "crossover interference". We investigate the logic and mechanism of this one-dimensional spatial patterning. We propose that the pattern arises by a mechanical process (Kleckner et al., 2004; Boerner et al., 2004; Zhang et al. 2014, Nature; White et al., 2017). Recent findings (Dubois et al., 2019) suggest that the mechanism may be directly related to the process that gives evenly-spaced bridges along mitotic chromosomes (above). We investigate the molecular nature of crossover interference by 3D imaging of individual chromosomes and recombination complexes in C. elegans using a microfluidic system that immobilizes worms. We hope that this system will ultimately allow us to visualize the interference signal as it progresses along the chromosomes.
Sordaria Meiosis. We also collaborate extensively with the laboratory of Denise Zickler to analyze the roles meiotic bridges and the roles of of long non-coding RNAs and other molecules in the processes of pairing and patterning in the filamentous fungus Sordaria (e.g. Zhang et al.,2014 PNAS; Dubois et al., 2019).
Human Aneuploidy, Plant Polyploidy, and Evolution. We are also interested in the roles of meiotic crossing-over and crossover interference for human female aneuploidy (Wang et al., 2017); for evolution of stable allotetraploidy in Arabidopsis (Bomblies et al., 2016); and for the role of crossing-over in evolutionary fitness (Wang et al., 2019, Veller et al., 2019).
Other Research Interests
Mitotic Chromosomes as Mechanical Objects
E. coli Chromosomes