In bacteriology, '''minicells''' are bacterial cells that are smaller than usual. The first minicells reported were from a strain of ''Escherichia coli'' that had a mutation in the Min System that lead to mis-localization of the septum during cell division and the production of cells of random sizes.<ref>{{Cite journal|last1=de Boer|first1=Piet A.J.|last2=Crossley|first2=Robin E.|last3=Rothfield|first3=Lawrence I.|date=February 1989|title=A division inhibitor and a topological specificity factor coded for by the minicell locus determine proper placement of the division septum in E. coli|url=https://linkinghub.elsevier.com/retrieve/pii/0092867489905862|journal=Cell|language=en|volume=56|issue=4|pages=641–649|doi=10.1016/0092-8674(89)90586-2|pmid=2645057|s2cid=7650379|url-access=subscription}}</ref><ref name=":0">{{Cite journal|last1=Adler|first1=H. I.|last2=Fisher|first2=W. D.|last3=Cohen|first3=A.|last4=Hardigree|first4=A. A.|date=1967-02-01|title=MINIATURE escherichia coli CELLS DEFICIENT IN DNA|journal=Proceedings of the National Academy of Sciences|language=en|volume=57|issue=2|pages=321–326|doi=10.1073/pnas.57.2.321|issn=0027-8424|pmc=335508|pmid=16591472|bibcode=1967PNAS...57..321A|doi-access=free}}</ref>
== Generation of minicells == The first report of minicells in scientific literature dates to 1930,<ref>{{Citation|last1=Frazer|first1=Anne Cornish|date=1975|url=http://link.springer.com/10.1007/978-3-642-50112-8_1|volume=69|pages=1–84|editor-last=Arber|editor-first=W.|publisher=Springer Berlin Heidelberg|language=en|doi=10.1007/978-3-642-50112-8_1|isbn=978-3-642-50114-2|access-date=2020-03-19|last2=Curtiss|first2=Roy|title=Current Topics in Microbiology and Immunology |chapter=Production, Properties and Utility of Bacterial Minicells |pmid=1098854|editor2-last=Henle|editor2-first=W.|editor3-last=Hofschneider|editor3-first=P. H.|editor4-last=Humphrey|editor4-first=J. H.|url-access=subscription}}</ref> but the first use of the term "minicell" dates to 1967.<ref name=":0" />
Minicells of a variety of gram negative<ref>{{Cite journal|last1=Treuner-Lange|first1=Anke|last2=Aguiluz|first2=Kryssia|last3=van der Does|first3=Chris|last4=Gómez-Santos|first4=Nuria|last5=Harms|first5=Andrea|last6=Schumacher|first6=Dominik|last7=Lenz|first7=Peter|last8=Hoppert|first8=Michael|last9=Kahnt|first9=Jörg|last10=Muñoz-Dorado|first10=José|last11=Søgaard-Andersen|first11=Lotte|date=January 2013|title=PomZ, a ParA-like protein, regulates Z-ring formation and cell division in Myxococcus xanthus: Regulation of cell division in M. xanthus|journal=Molecular Microbiology|language=en|volume=87|issue=2|pages=235–253|doi=10.1111/mmi.12094|pmid=23145985|s2cid=206191217|doi-access=free}}</ref> and gram positive<ref>{{Cite journal|last1=Lee|first1=Jin-Young|last2=Choy|first2=Hyon E.|last3=Lee|first3=Jin-Ho|last4=Kim|first4=Geun-Joong|date=2015-04-28|title=Generation of Minicells from an Endotoxin-Free Gram-Positive Strain Corynebacterium glutamicum|journal=Journal of Microbiology and Biotechnology|language=en|volume=25|issue=4|pages=554–558|doi=10.4014/jmb.1408.08037|pmid=25341464|issn=1017-7825|doi-access=free}}</ref><ref>{{Cite journal|last1=Reeve|first1=John N.|last2=Mendelson|first2=Neil H.|last3=Coyne|first3=Sheila I.|last4=Hallock|first4=Linda L.|date=1973-05-01|title=Minicells of Bacillus subtilis|url=https://jb.asm.org/content/114/2/860|journal=Journal of Bacteriology|language=en|volume=114|issue=2|pages=860–873|doi=10.1128/jb.114.2.860-873.1973|issn=0021-9193|pmid=4196259|pmc=251848}}</ref> bacteria, including ''Escherichia coli''<ref>{{Cite journal|last1=Ward|first1=John E.|last2=Lutkenhaus|first2=Joe|date=October 1985|title=Overproduction of FtsZ induces minicell formation in E. coli|url=https://linkinghub.elsevier.com/retrieve/pii/0092867485902909|journal=Cell|language=en|volume=42|issue=3|pages=941–949|doi=10.1016/0092-8674(85)90290-9|pmid=2996784|s2cid=36603663|url-access=subscription}}</ref> and ''Salmonella enterica'',<ref>{{Cite journal|last1=Kawamoto|first1=Akihiro|last2=Morimoto|first2=Yusuke V.|last3=Miyata|first3=Tomoko|last4=Minamino|first4=Tohru|last5=Hughes|first5=Kelly T.|last6=Kato|first6=Takayuki|last7=Namba|first7=Keiichi|date=December 2013|title=Common and distinct structural features of Salmonella injectisome and flagellar basal body|url= |journal=Scientific Reports|language=en|volume=3|issue=1|pages=3369|doi=10.1038/srep03369|issn=2045-2322|pmc=3842551|pmid=24284544|bibcode=2013NatSR...3E3369K}}</ref> have been reported, but in principle, minicells could be generated for any bacterial species that can be genetically edited. Minicells cannot reproduce because they do not contain a full copy of the genome.<ref name=":1">{{Cite journal|last1=Rang|first1=Camilla U.|last2=Proenca|first2=Audrey|last3=Buetz|first3=Christen|last4=Shi|first4=Chao|last5=Chao|first5=Lin|date=2018-09-19|editor-last=Bowman|editor-first=Grant R.|title=Minicells as a Damage Disposal Mechanism in Escherichia coli|url= |journal=mSphere|language=en|volume=3|issue=5|pages=e00428–18, /msphere/3/5/mSphere428–18.atom|doi=10.1128/mSphere.00428-18|doi-access=free|issn=2379-5042|pmc=6147132|pmid=30232168}}</ref>
== Normal role of minicells in bacteriology == Scientists hypothesize that minicells are produced by normal bacteria in times of stress so that damaged areas of the cell can be expelled.<ref name=":1" />
== Applications of minicells == Minicells have been extensively used to study ultrastructure of bacteria using electron cryotomography (cryoET).<ref>{{Cite journal|last1=Farley|first1=Madeline M.|last2=Hu|first2=Bo|last3=Margolin|first3=William|last4=Liu|first4=Jun|date=2016-04-15|editor-last=de Boer|editor-first=P.|title=Minicells, Back in Fashion|url= |journal=Journal of Bacteriology|language=en|volume=198|issue=8|pages=1186–1195|doi=10.1128/JB.00901-15|issn=0021-9193|pmc=4859596|pmid=26833418}}</ref><ref>{{Cite journal|last1=Liu|first1=Jun|last2=Chen|first2=Cheng-Yen|last3=Shiomi|first3=Daisuke|last4=Niki|first4=Hironori|last5=Margolin|first5=William|date=September 2011|title=Visualization of bacteriophage P1 infection by cryo-electron tomography of tiny Escherichia coli|url= |journal=Virology|language=en|volume=417|issue=2|pages=304–311|doi=10.1016/j.virol.2011.06.005|pmc=3163801|pmid=21745674}}</ref><ref>{{Cite journal|last1=Briegel|first1=A.|last2=Li|first2=X.|last3=Bilwes|first3=A. M.|last4=Hughes|first4=K. T.|last5=Jensen|first5=G. J.|last6=Crane|first6=B. R.|date=2012-03-06|title=Bacterial chemoreceptor arrays are hexagonally packed trimers of receptor dimers networked by rings of kinase and coupling proteins|journal=Proceedings of the National Academy of Sciences|language=en|volume=109|issue=10|pages=3766–3771|doi=10.1073/pnas.1115719109|issn=0027-8424|pmc=3309718|pmid=22355139|bibcode=2012PNAS..109.3766B|doi-access=free}}</ref> Minicells are ideal for cryoET because they are small enough for the electron beam to penetrate in transmission electron microscopy.
Bacterial minicells are being developed as a drug delivery system.<ref>{{Cite web|url=http://vaxiion.com/recombinant-bacterial-minicells--rbmcs-.html|title=Recombinant Bacterial Minicells (rBMCs)|website=Vaxiion Therapeutics|language=en|access-date=2020-03-19}}</ref><ref>{{Cite journal|last1=MacDiarmid|first1=Jennifer A.|last2=Mugridge|first2=Nancy B.|last3=Weiss|first3=Jocelyn C.|last4=Phillips|first4=Leo|last5=Burn|first5=Adam L.|last6=Paulin|first6=Richard P.|last7=Haasdyk|first7=Joel E.|last8=Dickson|first8=Kristie-Ann|last9=Brahmbhatt|first9=Vatsala N.|last10=Pattison|first10=Scott T.|last11=James|first11=Alexander C.|date=May 2007|title=Bacterially Derived 400 nm Particles for Encapsulation and Cancer Cell Targeting of Chemotherapeutics|journal=Cancer Cell|language=en|volume=11|issue=5|pages=431–445|doi=10.1016/j.ccr.2007.03.012|pmid=17482133|doi-access=free}}</ref> Minicells could be used to deliver genetic material to eukaryotic cells for gene editing.<ref>{{Cite journal|last1=Giacalone|first1=Matthew J.|last2=Gentile|first2=Angela M.|last3=Lovitt|first3=Brian T.|last4=Xu|first4=Tong|last5=Surber|first5=Mark W.|last6=Sabbadini|first6=Roger A.|date=October 2006|title=The use of bacterial minicells to transfer plasmid DNA to eukaryotic cells|url=http://doi.wiley.com/10.1111/j.1462-5822.2006.00737.x|journal=Cellular Microbiology|language=en|volume=8|issue=10|pages=1624–1633|doi=10.1111/j.1462-5822.2006.00737.x|pmid=16984417|s2cid=39889761|issn=1462-5814|url-access=subscription}}</ref> They are also being investigated for vaccine development.<ref>{{Cite journal|last1=Carleton|first1=Heather A.|last2=Lara-Tejero|first2=María|last3=Liu|first3=Xiaoyun|last4=Galán|first4=Jorge E.|date=June 2013|title=Engineering the type III secretion system in non-replicating bacterial minicells for antigen delivery|url= |journal=Nature Communications|language=en|volume=4|issue=1|pages=1590|doi=10.1038/ncomms2594|issn=2041-1723|pmc=3693737|pmid=23481398|bibcode=2013NatCo...4.1590C}}</ref>
== References == {{Reflist}}
== Further reading == * [https://openwetware.org/wiki/Minicells Minicells, at openwetware.org] * [https://schaechter.asmblog.org/schaechter/2007/07/minicells-on--1.html Minicells on Target]
Category:Bacteriology