Faculty and Research
Faculty by Name
Abby Dernburg
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Abby Dernburg
Associate Professor of Cell and Developmental Biology*
*And Senior Scientist, Life Sciences Division, Lawrence Berkeley National Laboratory
Research Interests
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For genetic information to be transmitted from parent to progeny through sexual reproduction, chromosomes must undergo a special division process called meiosis. Errors in this process lead to aneuploidy and are a major cause of human birth defects such as Down syndrome. We are investigating how chromosomes are reorganized during this unique cell cycle by combining high-resolution imaging of chromosomes in situ and in vivo with the molecular genetic advantages of C. elegans. A fundamental goal of our work is to understand how specific DNA sequences confer not only gene expression patterns but also the large-scale 3-dimensional organization of the genome.
Current Projects
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Dissecting the function of meiotic Pairing Centers. When most people think of genomics, they often consider only the portion of the genome containing protein coding and expression information. My group is interested how information encoded within the genome controls global chromosome architecture and mediates interactions between chromosomes and other components of the cellular machinery. In all eukaryotes, simple, repetitive sequence elements play major roles in chromosome structure and inheritance functions. For example, work in a variety of organisms has elucidated the behavior of centromeres and telomeres, two types of sites containing noncoding sequences with fundamental roles in chromosome organization and function. We are exploring the function of another type of cisacting site that is much more poorly understood: meiotic Pairing Centers. In C. elegans, these specific sites on each of the six chromosomes are essential for meiotic recombination and accurate segregation.
New tools for understanding noncoding DNA sequences have become available through genome sequencing efforts. C. elegans is unusual in that its genome assemblies now include virtually all of the so-called "junk DNA" - the simple-sequence repetitive elements, or heterochromatin. Through bioinformatics, we have identified a unique repetitive element whose genomic distribution corresponds precisely with the location of meiotic Pairing Centers, and we are currently testing whether this sequence can mediate homologous interactions during meiosis. Using classical and reverse genetics, we have also identified a number of genes that interact with the Pairing Centers, and we are working to understand how their encoded proteins contribute to the function of these sites.
Meiotic chromosome dynamics in vivo. A major goal of our lab is to understand how the biophysical properties of chromosomes are modulated during meiosis, and how these properties control behaviors such as homolog pairing and recombination. Because C. elegans is optically transparent, we can observe these dynamic events as they occur in living animals. We have recorded large-scale chromosome movements during the stages of homolog pairing and synapsis using high-resolution 4-dimensional imaging. We are identifying the molecules driving this movement, and developing methods to describe these dynamics quantitatively. A key goal for the future is to implement automated methods to extract information from complex 4-D images.
Selected Publications
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A link between meiotic prophase progression and crossover control. [P.M. Carlton, A. Farrugio, and A.F. Dernburg (2006) PLoS Genetics, 2: e12]
HIM-8 binds to the X chromosome Pairing Center and mediates chromosome-specific meiotic synapsis. [C.M. Phillips, C. Wong, N. Bhalla, P. Meneely, and A.F. Dernburg (2005) Cell, 123: 1051-63]
Chromosome sites play dual roles to establish homolog synapsis during meiois in C. elegans. [A.J. MacQueen, C.M. Phillips, N. Bhalla., P. Weiser, A.M. Villeneuve, and A.F. Dernburg. (2005) Cell, 123: 1037-50]
Chromosome synapsis is monitored by a conserved meiotic checkpoint. [N. Bhalla and A.F. Dernburg (2005) Science 310: 1683-6]
A chromosome RNAissance. [ A.F. Dernburg and G.H. Karpen (2002) Cell 111, 159-162]
Last Updated 2004-11-05