Project Summary (NSF award #: 0603927)
The centromere is a cytologically defined entity with highly conserved functions: it is responsible for sister chromatid cohesion and is the site for the assembly of kinetochore to which spindle fibers attach during cell division. In most multicellular eukaryotes, the centromeres are embedded within heterochromatin and are associated with long tracts of satellite repeats. Thus, the centromere is traditionally considered a highly heterochromatic and genetically silent chromosomal domain. Recent research work from human neocentromeres and our work on the centromere of rice chromosome 8 (Cen8) suggest that centromeres are originated from genic regions. We propose to study centromere evolution using Cen8 as a model. The results from the proposed research will shed light on centromere evolution and will build a foundation to study evolution of genes located in heterochromatic and recombinationally-suppressed chromosomal domains.

Specific Aims
Develop BAC-based physical maps that span the Cen8 in six diploid Oryza species. Produce approximately 1 Mb of DNA sequence from each of the six minimum tiling paths that span Cen8 of these six species. Determine the functional boundary of Cen8 by chromatin immunoprecipitation (ChIP) using antibody against the rice centromeric histone H3 (CENH3). Analyze structural rearrangements and sequence divergence associated with Cen8. Explore expression and evolution of Cen8-associated genes to understand how such genes adapt in a unique chromosomal domain.

Principle Investigators
Jiming Jiang (PI): University of Wisconsin-Madison
Rod A. Wing (Co-PI): University of Arizona, Arizona Genomics Institute
Scott A. Jackson (Co-PI): Purdue University