Showing papers by "Daniel E. Gottschling published in 2004"

The histone modification pattern of active genes revealed through genome-wide chromatin analysis of a higher eukaryote

Abstract: The covalent modification of nucleosomal histones has emerged as a major determinant of chromatin structure and gene activity. To understand the interplay between various histone modifications, including acetylation and methylation, we performed a genome-wide chromatin structure analysis in a higher eukaryote. We found a binary pattern of histone modifications among euchromatic genes, with active genes being hyperacetylated for H3 and H4 and hypermethylated at Lys 4 and Lys 79 of H3, and inactive genes being hypomethylated and deacetylated at the same residues. Furthermore, the degree of modification correlates with the level of transcription, and modifications are largely restricted to transcribed regions, suggesting that their regulation is tightly linked to polymerase activity.

Automation of yeast pedigree analysis

Abstract: Yeast pedigree analysis-isolation and characterization of the products of mitotic cell divisions throughout the lifespan of an individual cell-is a manually intensive process that requires a biologist to manipulate single yeast cells every 90 minutes for as long as 150 hours. Progress toward the development of a system for automating yeast pedigree analysis is presented. Yeast cells are trapped in a microfluidic device, then observed using a fiber-optic imaging bundle. Image processing software classifies each cell as either budding or not budding a newly formed daughter cell. The system recognizes when a cell has a bud, and microfluidic valves direct newly formed daughter cells to an agar plate. Finally, biologists analyze the colonies formed by each yeast daughter cell on the agar plate.