研究人员假设自然选择广泛倾向于特定的染色体位置，以优化生长速率依赖的表达。通过对大肠杆菌和枯草芽胞杆菌910种细菌和蛋白质组学数据的分析，该课题组人员发现大约三分之二的细菌基因家族存在位置偏倚。自然选择主要驱使基因走向复制的起点或终点，在快速生长的物种中选择最强烈。他们的发现揭示了染色体定位是协调基因表达与生长速度的基本机制，突出了细菌基因组结构的进化限制。
研究人员表示，在DNA复制过程中，基因沿细菌染色体的排列通过生长速率依赖的基因拷贝数变化影响其表达。尽管与翻译和转录相关的基因通常聚集在复制起源附近，但基因家族之间的位置偏差程度仍不清楚。
附：英文原文
Title: Most bacterial gene families are biased toward specific chromosomal positions
Author: Xiao-Pan Hu, Bayu Brahmantio, Krzysztof Bartoszek, Martin J. Lercher
Issue&Volume: 2025-04-11
Abstract: The arrangement of genes along bacterial chromosomes influences their expression through growth rate–dependent gene copy number changes during DNA replication. Although translation- and transcription-related genes often cluster near the origin of replication, the extent of positional biases across gene families remains unclear. We hypothesized that natural selection broadly favors specific chromosomal positions to optimize growth rate–dependent expression. Analyzing 910 bacterial species and proteomics data from Escherichia coli and Bacillus subtilis, we found that about two-thirds of bacterial gene families are positionally biased. Natural selection drives genes mainly toward the origin or terminus of replication, with the strongest selection in fast-growing species. Our findings reveal chromosomal positioning as a fundamental mechanism for coordinating gene expression with growth rate, highlighting evolutionary constraints on bacterial genome architecture.
DOI: adm9928
Source: https://www.science.org/doi/10.1126/science.adm9928