TY - JOUR
T1 - Engineering Natural Competence into the Fast-Growing Cyanobacterium Synechococcus elongatus Strain UTEX 2973
AU - Wendt, Kristen E.
AU - Walker, Patricia
AU - Sengupta, Annesha
AU - Ungerer, Justin
AU - Pakrasi, Himadri B.
N1 - Funding Information:
This study was supported by National Science Foundation Grants MCB-1546840 and MCB-1933660 to H.B.P. K.E.W. was partially supported by a William H. Danforth Fellowship at Washington University in St. Louis. We thank members of the Pakrasi Lab for collegial discussions.
Publisher Copyright:
© 2022 American Society for Microbiology. All Rights Reserved.
PY - 2022/1
Y1 - 2022/1
N2 - Natural transformation is the process by which bacteria actively take up and integrate extracellular DNA into their genomes. In cyanobacteria, natural transformation has only been experimentally demonstrated in a few species. Although cyanobacteria are important model systems for studying photosynthesis and circadian cycling, natural transformation in cyanobacteria has not been characterized to the degree that the process has been studied in other Gram-negative bacteria. Two cyanobacterial species that are 99.8% genetically identical provide a unique opportunity to better understand the nuances of natural transformation in cyanobacteria: Synechococcus elongatus PCC 7942 and Synechococcus elongatus UTEX 2973 (hereafter called Synechococcus 7942 and Synechococcus 2973, respectively). Synechococcus 7942 is a naturally transformable model system, while Synechococcus 2973 is a recently discovered species that is not naturally competent. Taking only 1.5 h to replicate, Synechococcus 2973 is the fastest-growing cyanobacterial species known and thus is a strong candidate for serving as a model organism. However, its inability to undergo natural transformation has prevented it from becoming a widely used model system. By substituting polymorphic alleles from Synechococcus 7942 for native Synechococcus 2973 alleles, natural transformation was introduced into Synechococcus 2973. Two genetic loci were found to be involved in differential natural competence between the two organisms: transformation pilus component pilN and circadian transcriptional master regulator rpaA. By using targeted genome editing and enrichment outgrowth, a strain that was both naturally transformable and fast-growing was created. This new Synechococcus 2973-T strain will serve as a valuable resource to the cyanobacterial research community.
AB - Natural transformation is the process by which bacteria actively take up and integrate extracellular DNA into their genomes. In cyanobacteria, natural transformation has only been experimentally demonstrated in a few species. Although cyanobacteria are important model systems for studying photosynthesis and circadian cycling, natural transformation in cyanobacteria has not been characterized to the degree that the process has been studied in other Gram-negative bacteria. Two cyanobacterial species that are 99.8% genetically identical provide a unique opportunity to better understand the nuances of natural transformation in cyanobacteria: Synechococcus elongatus PCC 7942 and Synechococcus elongatus UTEX 2973 (hereafter called Synechococcus 7942 and Synechococcus 2973, respectively). Synechococcus 7942 is a naturally transformable model system, while Synechococcus 2973 is a recently discovered species that is not naturally competent. Taking only 1.5 h to replicate, Synechococcus 2973 is the fastest-growing cyanobacterial species known and thus is a strong candidate for serving as a model organism. However, its inability to undergo natural transformation has prevented it from becoming a widely used model system. By substituting polymorphic alleles from Synechococcus 7942 for native Synechococcus 2973 alleles, natural transformation was introduced into Synechococcus 2973. Two genetic loci were found to be involved in differential natural competence between the two organisms: transformation pilus component pilN and circadian transcriptional master regulator rpaA. By using targeted genome editing and enrichment outgrowth, a strain that was both naturally transformable and fast-growing was created. This new Synechococcus 2973-T strain will serve as a valuable resource to the cyanobacterial research community.
KW - Cyanobacteria
KW - Fast-growth
KW - Natural transformation systems
KW - Pili
KW - RpaA
UR - http://www.scopus.com/inward/record.url?scp=85123456014&partnerID=8YFLogxK
U2 - 10.1128/AEM.01882-21
DO - 10.1128/AEM.01882-21
M3 - Article
C2 - 34705549
AN - SCOPUS:85123456014
SN - 0099-2240
VL - 88
JO - Applied and Environmental Microbiology
JF - Applied and Environmental Microbiology
IS - 1
M1 - e01882-21
ER -