Cornell University Department of Plant Breeding and Genetics

Pawlowski lab website

My goal is to understand the mechanisms of meiosis, especially focusing on homologous chromosome pairing and meiotic recombination. Meiosis is the specialized type of cell division that reduces the chromosome number in the nucleus from 2n to 1n and leads to the production of gametes. During meiosis, homologous chromosomes, one from the mother and the other one from the father, pair with each other and exchange parts (recombine). These processes are essential for accurate transmission of genetic material from parents to the progeny and for generating genetic variation.

At the beginning of meiosis, chromatin in the nucleus undergoes a dramatic reorganization. During this time, double-strand DNA breaks are generated on chromosomes, which initiates meiotic recombination. Subsequently, homologous chromosomes recognize each other and pair. The past decade has brought dramatic improvements in the understanding of meiotic processes. However, many aspects of meiosis, especially the mechanism of homologous chromosome pairing, remain unknown.

My research combines classical genetics and cutting-edge genomic, proteomic, and molecular genetic approaches with state-of-the-art 3-dimensional microscopy to identify genes, proteins, and pathways that play key roles in meiosis. My goals are to elucidate: (1) what is the mechanism of homologous chromosome pairing, (2) what is the relationship between chromosome pairing and meiotic recombination, and (3) how are meiotic recombination, paring, and synapsis coordinated. To address these questions, I use three model plant systems, maize (Zea mays) and rice (Oryza sativa), two of the most important crop plants in the world, and a common weed, Arabidopsis thaliana.

SELECTED PUBLICATIONS:

Pawlowski W.P., Golubovskaya, I.N., Timofejeva, L., Meeley R. B., Sheridan W.F., Cande W.Z. 2004. Coordination of meiotic recombination, pairing, and synapsis by PHS1. Science 303: 89-92. (Accompanied by "Perspective" commentary: Martinez-Perez E., Moore G. 2004. Promiscuous maize chromosomes. Science 303: 49-50.)

Pawlowski W.P., Golubovskaya, I.N., Cande W.Z. 2003. Altered nuclear distribution of recombination protein RAD51 in maize mutants suggests involvement of RAD51 in the meiotic homology recognition. Plant Cell 8: 1807-1816.

Golubovskaya, I.N., Harper L., Pawlowski W.P., Cande W.Z. 2002. The pam1 gene is required for meiotic bouquet formation and efficient homologous synapsis in maize. Genetics 162: 1979-1993.

Svitashev* S.K., Pawlowski* W.P., Makarevitch I., Plank D.W., Somers D.A. (* equal first co-authors) 2002. Complex transgene locus structures implicate multiple mechanisms for plant transgene rearrangement. Plant Journal 32: 433-445.

Pawlowski W.P., Somers D.A. 1998. Transgenic DNA integrated into the oat genome is frequently interspersed by host DNA. PNAS 95: 12106-12110.

© 2006 Department of Plant Breeding and Genetics, Cornell University