biostudies-literatureUnknown9Kimura SThe freshwater cyanobacterium <i>Microcystis aeruginosa</i> frequently forms toxic massive blooms and exists in an arms race with its infectious phages in aquatic natural environments, and as a result, has evolved extremely diverse and elaborate antiviral defense systems, including the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated genes (Cas) system. Here, to assess <i>Microcystis</i> population dynamics associated with exogenous mobile genetic elements such as phages and plasmids, we examined the temporal variation in CRISPR genotypes (CTs) by analyzing spacer sequences detected in a natural pond between June and October 2013 when a cyanobacterial bloom occurred. A total of 463,954 high-quality leader-end CRISPR sequences were obtained and the sequenFrontiers in microbiology425https://www.ebi.ac.uk/biostudies/studies/S-EPMC5852275biostudies-literatureIncomplete Selective Sweeps of <i>Microcystis</i> Population Detected by the Leader-End CRISPR Fragment Analysis in a Natural Pond.PMC5852275Morimoto DSako YYamanaka MKimura SYoshida TUehara MfalseIncomplete Selective Sweeps of <i>Microcystis</i> Population Detected by the Leader-End CRISPR Fragment Analysis in a Natural Pond.The freshwater cyanobacterium <i>Microcystis aeruginosa</i> frequently forms toxic massive blooms and exists in an arms race with its infectious phages in aquatic natural environments, and as a result, has evolved extremely diverse and elaborate antiviral defense systems, including the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated genes (Cas) system. Here, to assess <i>Microcystis</i> population dynamics associated with exogenous mobile genetic elements such as phages and plasmids, we examined the temporal variation in CRISPR genotypes (CTs) by analyzing spacer sequences detected in a natural pond between June and October 2013 when a cyanobacterial bloom occurred. A total of 463,954 high-quality leader-end CRISPR sequences were obtained and the sequen2018-01-01T00:00:00Z20182026-04-08T00:05:43.477Z2019-03-26T23:23:01ZS-EPMC58522752956829310.3389/fmicb.2018.00425