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Wojtek Pawlowski

Associate Professor

401 Bradfield Hall
(607) 254-8745

Research Focus

My long-term interest is elucidating genetic mechanisms controlling chromosome interactions in meiosis. To achieve this goal, our lab pursues two major research themes: (i) understanding the patterns of distribution of meiotic recombination events along chromosomes as well as the factors that control these patterns and (ii) elucidating factors that affect chromosome dynamics during early prophase of meiosis, particularly rapid chromosome movements that lead to homologous chromosome pairing. These basic research studies will provide a platform for investigations on how meiotic processes can be modified to improve plant breeding methods. Currently, the main projects in the lab currently are:

(1) Understanding Recombination in Maize (sponsored by NSF). Recombination is the main source of genetic variation in higher eukaryotes; it facilitates adaptation, purges deleterious mutations from genomes and populations, and is a major determinant of genome architecture. In addition, recombination is utilized as an unparalleled instrument of plant breeding. We generated the first map of sites where recombination is initiated in the genome of a plant (maize) by formation of double-strand breaks in chromosomal DNA. Few of these breaks are repaired to produce chromosomal arm exchanges (crossovers), leaving about one-fifth of maize genes in regions of highly reduced crossover rates. We found that specific chromatin features are the main factors deciding which recombination events become crossovers. Developing ways to increase crossovers in crossover-depressed regions will allow utilizing higher numbers of allele combinations in breeding programs, leading to more efficient breeding.

(2) Chromosome axis dynamics during meiotic recombination (sponsored by ERA-CAPS/NSF). As a part of an international group of plant scientists we study how chromosome reorganization in meiosis and chromosome dynamics affect recombination outcomes, i.e., how they contribute to meiotic crossovers being formed in specific chromosome locations. To address this question, we use several advanced microscopy methods, such as restorative deconvolution, multiphoton excitation, and structured illumination microscopy.

(3) Meiotic recombination and genome rearrangements in new polyploids. Polyploidization events have been frequent in plant evolution. Many plant species and most crops are polyploid. Most polyploidization events are followed by rapid and extensive genome rearrangement. The predominant mechanism of these rearrangements is illegitimate recombination (IR) taking place during meiosis. These changes can occur on a massive scale in the first few generations following a polyploidization event, but they are also thought to continue several million years thereafter. How meiotic recombination acts to restructure the genomes of newly created polyploids is not understood. We utilize knowledge of meiotic recombination in diploids to elucidate molecular mechanisms controlling genome restructuring in polyploids.

Outreach and Extension Focus

As part of a collaborative NSF-sponsored project, my colleagues at the University of Minnesot and I jointly operate a Science Undergraduate Minority Mentoring Internship and Training (SUMMIT) program, which sponsors four 10-week internships for minority undergraduate students ( The interns participate in research in the three laboratories involved in the project, at Cornell and the University of Minnesota. They also attend weekly seminars, discussions, and training sessions that cover such professional development topics as networking, resume/CV and personal statement preparation, elevator pitches, data presentation, and scientific writing.

Teaching Focus

I teach courses in genetics and evolution, including Plant Evolutionary Biology (PLBIO2440), Advanced Plant Genetics (PLBRG6060), and Laboratory in Plant Molecular Biology (PLBIO6410).

Selected Publications

Journal Publications