Editing Plasmid (section)

===Chromids===
{{main|Chromid}}
Chromids are elements that exist at the boundary between a [[chromosome]] and a plasmid, found in about 10% of bacterial species sequenced by 2009. These elements carry core genes and have [[codon usage]] similar to the chromosome, yet use a plasmid-type replication mechanism such as the low copy number RepABC. As a result, they have been variously classified as minichromosomes or megaplasmids in the past.<ref>{{cite journal | vauthors = Harrison PW, Lower RP, Kim NK, Young JP | title = Introducing the bacterial 'chromid': not a chromosome, not a plasmid | journal = Trends in Microbiology | volume = 18 | issue = 4 | pages = 141–148 | date = April 2010 | pmid = 20080407 | doi = 10.1016/j.tim.2009.12.010 }}</ref> In ''[[Vibrio]]'', the bacterium synchronizes the replication of the chromosome and chromid by a conserved genome size ratio.<ref name=Bruhn>{{cite journal | vauthors = Bruhn M, Schindler D, Kemter FS, Wiley MR, Chase K, Koroleva GI, Palacios G, Sozhamannan S, Waldminghaus T | title = Functionality of Two Origins of Replication in ''Vibrio cholerae'' Strains With a Single Chromosome | journal = Frontiers in Microbiology | volume = 9 | pages = 2932 | date = 30 November 2018 | pmid = 30559732 | pmc = 6284228 | doi = 10.3389/fmicb.2018.02932 | doi-access = free }}</ref>