title: Genome sequences of two closely related strains of Escherichia coli K-12 GM4792.
abstract: Escherichia coli lab strains K-12 GM4792 Lac(+) and GM4792 Lac(-) carry opposite lactose markers, which are useful for distinguishing evolved lines as they produce different colored colonies. The two closely related strains are chosen as ancestors for our ongoing studies of experimental evolution. Here, we describe the genome sequences, annotation, and features of GM4792 Lac(+) and GM4792 Lac(-). GM4792 Lac(+) has a 4,622,342-bp long chromosome with 4,061 protein-coding genes and 83 RNA genes. Similarly, the genome of GM4792 Lac(-) consists of a 4,621,656-bp chromosome containing 4,043 protein-coding genes and 74 RNA genes. Genome comparison analysis reveals that the differences between GM4792 Lac(+) and GM4792 Lac(-) are minimal and limited to only the targeted lac region. Moreover, a previous study on competitive experimentation indicates the two strains are identical or nearly identical in survivability except for lactose utilization in a nitrogen-limited environment. Therefore, at both a genetic and a phenotypic level, GM4792 Lac(+) and GM4792 Lac(-), with opposite neutral markers, are ideal systems for future experimental evolution studies.
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Street, Beijing, 100875 China.
authors.forename: Yan-Cong
authors.initials: YC
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Street, Beijing, 100875 China ; Present address: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Street, Beijing, 100875 China.
authors.forename: Bi-Ru
authors.initials: BR
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Street, Beijing, 100875 China.
authors.forename: Bo-Wen
authors.initials: BW
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Street, Beijing, 100875 China ; Present address: The second high school attached to Beijing Normal University, Beijing, 100192 China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Ni
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Street, Beijing, 100875 China.
authors.forename: Da-Yong
authors.initials: DY
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, and National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206 China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Street, Beijing, 100875 China.
authors.forename: Erli
authors.initials: E
authors.lastname: Pang
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Street, Beijing, 100875 China.
authors.forename: Kui
authors.identifier: 0000-0002-5993-1972
authors.initials: K
authors.lastname: Lin
keywords: Escherichia coli K12; Experimental evolution; GM4792; Genome comparison; Gram-negative; Lactose; Variant analysis