Research and Professional Interests:

Our long-term research goals are to elucidate the molecular mechanism responsible for the formation of the meiotic chromosome architecture and to examine the role chromosome organization plays in safeguarding genomic integrity. In contrast to mitosis, where paired sister chromatids separate, during meiosis I, homologs pair, recombine, then separate; meanwhile, sisters are joined together until meiosis II. Understanding the dynamics of meiotic chromosome organization and segregation can provide insights into the causes of birth defects, aneuploidy, and developmental abnormalities in humans.

Our current research is focused on chromosome structural organization in the model organism Saccharomyces cerevisiae, baker’s yeast, whose genome is less than half of a percent of the size of the human genome. Besides its power of genetics, yeast has the additional advantage that its meiosis is inducible and can be highly synchronized, a property that makes it very suitable for biochemical analysis of the chromosome structure and function. As an entry point, our lab studies two evolutionarily conserved protein complexes called condensin and cohesin that play key roles in meiotic chromosome organization and segregation. With mutant alleles that are compromised only for meiosis, we are uniquely positioned to address the following three questions:

1. How does condensin organize the meiotic chromosome structure in vivo?

2. How does condensin interact with cohesin to regulate meiotic recombination?

3. How is centromeric cohesin differentially regulated to produce homolog separation in meiosis I but sister chromatid separation in meiosis II?

Selected Publications:

Yu, H.-G, and D. E. Koshland. 2007. The Aurora kinase Ipl1 maintains the centromeric localization of PP2A to protect cohesin during meiosis. J. Cell Biol. 176: 911-918. (record in PubMed)

Yu, H.-G., and D. E. Koshland. 2005. Chromosome morphogenesis: condensin-dependent cohesin removal during meiosis. Cell 123:397-407. (record in PubMed)

Glynn, E. F., P. Megee, H.-G. Yu, C. Mistrot, E. Unal, D. E. Koshland, J. L. DeRisi, and J. L. Gerton. 2004. Genome-wide mapping of the cohesin complex in the yeast Saccharomyces cerevisiae. PLoS, Biology 2(9):1325-1339. (record in PubMed)

Yu, H.-G., and D. E. Koshland. 2003. Meiotic condensin is required for proper chromosome compaction, SC assembly, and resolution of recombination-dependent chromosome linkages. J. Cell Biol. 163:937-947. (record in PubMed)

Yu, H.-G., E. N. Hiatt, and R. K. Dawe. 2000. The plant kinetochore. Trends Plant Biol. 5:543-547. (record in PubMed)

Yu, H.-G., and R. K. Dawe. 2000. Functional redundancy in the maize meiotic kinetochore. J. Cell Biol. 151:131-141 (record in PubMed)

Dawe, R. K., L. M. Reed, H.-G. Yu, M. G. Muszynski, and E. N. Hiatt. 1999. A maize homolog of mammalian CENP-C is a constitutive component of the inner kinetochore. Plant Cell 11:1227-1238. (record in PubMed)

Yu, H.-G., M. G. Muszynski, and R. K. Dawe. 1999. The maize homolog of the cell cycle checkpoint protein MAD2 reveals kinetochore substructure and contrasting mitotic and meiotic localization patterns. J. Cell Biol. 145:425-435. (record in PubMed)

Yu, H.-G., E. N. Hiatt, A. Chang, M. Sweeney, and R. K. Dawe. 1997. Neocentromeremediated chromosome movement in maize. J. Cell Biol. 139:831-840. (record in PubMed)

Graduate Students:

Macy, Brett
Wang, Mian
 

A postdoctoral position is currently available in the laboratory.

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