The sequencing and analysis of human chromosome 3 provided a few surprises for researchers including Susan Naylor, Ph.D., professor of cellular and structural biology at the Health Science Center.
Dr. Naylor, along with Dawn Garcia, Xin He and Ruben Rodriguez of her laboratory, were among the dozens of U.S., Chinese, German and British co-authors of the final report on chromosome 3 that came out April 27 in Nature.www.nature.com/nature/journal/v440/n7088/full/nature04728.html
Ten other people from Dr. Naylor’s group who were instrumental in the sequencing effort were listed in a supplement to the Nature article.
The sequencing project revealed more details about a cluster of immunity-response genes on chromosome 3, including the gene that encodes CCR5, a co-factor important for entry of the human immunodeficiency virus (HIV) into cells.
Another area of chromosome 3 contains several genes that are linked to increased risk for kidney, esophageal, stomach and colon cancers. At least 505 disease-implicated genes have been mapped to chromosome 3, the authors note.
The chromosome is unique in another way. “Throughout the human genome, we see large regions of duplicated base sequences called repeats,” Dr. Naylor said. “That’s not the case with chromosome 3. Although it is among the largest human chromosomes, repeats make up only 1.7 percent of its content, compared to the genome-wide average of 5.3 percent.”
Sequencing the human genome at this high level of accuracy has led the way for sequencing many other mammals, Dr. Naylor said. Comparison of these sequences has helped unlock some of the significance of genome structure and function.