Detection of fundamental principles and a level of order for large-scale gene clustering on the Escherichia coli chromosome |
| |
Authors: | Rufus M. Williamson Jack Hetherington Julius H. Jackson |
| |
Affiliation: | (1) Department of Microbiology and Public Health, Michigan State University, 48824 East Lansing, MI, USA;(2) Department of Physics and Astronomy, Michigan State University, 48824 East Lansing, MI, USA;(3) Present address: Department of Biotechnology, Parke Davis, 48106 Ann Arbor, MI, USA |
| |
Abstract: | Summary The Escherichia coli K-12 genetic map was divided into intervals of equal length to count the number of genes per interval. Plots of genes per interval at four sets of interval lengths revealed large-scale clustering of genes with the major clusters occurring at regularly spaced distances apart. Major gene cluster properties were analyzed at a scale of 100 intervals wherein each interval corresponded to a genetic map unit length of 1 min. In any major gene cluster, the highest gene concentration was observed at or near the midpoint interval, and the number of genes per interval was found to decline exponentially as a function of the linear distance from the midpoint or interval of peak gene concentration of that cluster. An autocorrelation analysis of gene content in first-neighbor intervals throughout the chromosome revealed an ordered first-neighbor relationship in comparison to 2,000 randomized interval versions of the chromosome. Attempts to simulate gene placement by a Gaussian model did not produce large-scale gene clustering in any way comparable to that observed on the chromosome. We propose that major gene clusters formed from smaller gene clusters, and the contemporary chromosome formed from fusion of homologous or heterologous major gene clusters. |
| |
Keywords: | Chromosome evolution Gene evolution Bacterial chromosomal expansion Chromosomal gene organization Gene clustering Gene duplication Escherichia coli Bacteria |
本文献已被 SpringerLink 等数据库收录! |
|