John Tomkiel Dean

John Tomkiel Dean

John Tomkiel Dean

Associate Professor

(336) 334-4980
203 Eberhart Building


Chromosome segregation in meiosis, chromosomal proteins, Drosophila genetics.


Ph.D., University of Washington


I am interested in how chromosomes are partitioned into daughter cells upon cell division. My research is currently focused on chromosome segregation in meiosis, using the fruit fly Drosophila melanogaster as a model system. Errors in meiotic chromosome transmission are the single most common source of genetic syndromes in humans, affecting more than 1/500 live births. Studies in models organisms such as yeasts, flies and nematodes have provided us with a variety of clues about the causes of such errors. In my lab, we use molecular, cell and genetic approaches to characterize a collection of mutations that increase the frequency of the meiotic chromosome errors in the male fly. These studies may lead to the identification of genes and/or genetic pathways that are evolutionarily conserved, and may shed light on similar mechanisms that operate in humans.

Recent Publications:

Binder, A.M.,  B. T. Wakimoto, C. Davis, J. Chmielewski  and J. Tomkiel Dean, 2017.  Versager is expressed at the histone to protamine transition during spermiogenesis and is required for embryonic chromosome transmission in Drosophila melanogaster. Res. J. of Dev Biol. DOI :

Hylton, C.A., K. Hansen, A. Bourgoies, and J.E. Tomkiel Dean. 2020. Sex chromosome pairing mediated by euchromatic homology in Drosophila male meiosis.      Genetics 143: 605-616.

Matsui M, Sharma K, Cooke C, Wakimoto BT, Rasool M, Hayworth M, Hylton CA, Tomkiel JE. 2011 Sep 6. Nuclear Structure and Chromosome Segregation in Drosophila Male Meiosis Depend on the Ubiquitin Ligase dTopors.Genetics, [Epub ahead of print].



Genetics (BIO 392)
Genetics Lab (BIO 393)
Advanced Topics in Genetics: Genetics of Aging (BIO 506)
Epigenetics (BIO 587)