Duke University Medical Center
Faculty and Research

Heitman Lab Members

Helen Lai
Graduate Student

320 CARL Building
Box 3546 DUMC
Durham, N.C. 27710

Phone: 919.684.3036
Fax: 919.684.5458
Email: helen.lai@duke.edu 

Helen Lai

I graduated from the University of Washington at Seattle in 2012 and came to Duke through the Molecular Genetics and Microbiology graduate program. I am excited about my rotation in the Heitman Lab and working with post-doctoral fellow, Sheng Sun.

Here is a brief description of my project:

We are interested in C. amylolentus because it is the closest relative to the pathogenic fungus C. neoformans. Current effort in sequencing the genome faces difficulties in identifying the centromere regions. We aim to transform C. amylolentus with fluorescence-tagged centromere binding proteins from C. neoformans and then conduct chromatin immunoprecipitation followed by polymerase chain reaction and/or sequencing.

The tetrapolar mating system in C. amylolentus evolved before the bipolar mating system in C. neoformans. The joining of the two mating loci, HD and P/R, may have occurred through chromosome rearrangement mediated by homologous sequences. Whereas little is known about centromeres in C. amylolentus, one characteristic of the centromeres in its closest related species, C. neoformans, is the enrichment of repetitive sequences and transposable elements. Though recombination is generally suppressed near centromeres, rare recombination events using homologous centromere sequences may contribute to the evolution from tetrapolar to bipolar mating systems. Currently, we have progeny isolates with unique chromosomes that are different from their parents in size due to chromosome rearrangements. The aim is to identify the locations of recombination. If they are near the centromere region, the observation will support the hypothesis that centromere mediates chromosome rearrangements.

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