Editing Bacillus thuringiensis (section)

==Genetics==
Some strains are known to carry the same genes that produce [[enterotoxin]]s in ''B. cereus'', and so it is possible that the entire ''B. cereus'' sensu lato group may have the potential to be [[enteropathogen]]s.<ref name="Kolsto-et-al-2009" />

The proteins that ''B. thuringiensis'' is most known for are encoded by ''cry'' genes.<ref name="Circkmore-2008" /> In most strains of ''B. thuringiensis'', these genes are located on a [[plasmid]] (in other words ''cry'' is not a chromosomal gene in most strains).<ref name=Stahly>{{cite journal | vauthors = Dean DH | title = Biochemical genetics of the bacterial insect-control agent Bacillus thuringiensis: basic principles and prospects for genetic engineering | journal = Biotechnology & Genetic Engineering Reviews | volume = 2 | pages = 341–363 | year = 1984 | pmid = 6443645 | doi = 10.1080/02648725.1984.10647804 | doi-access = free }}</ref><ref name=Clayton1992>{{cite journal |doi=10.4039/Ent124587-4 |title=Invitation Paper (C.p. Alexander Fund): History Of ''bacillus Thuringiensis'' berliner Research and Development |year=1992 | vauthors = Beegle CC, Yamamoto T | journal=The Canadian Entomologist |volume=124 |issue=4 |pages=587–616|s2cid=86763021 }}</ref><ref name=Xu2006>{{cite journal | vauthors = Xu J, Liu Q, Yin X, Zhu S |year=2006|title=A review of recent development of Bacillus thuringiensis ICP genetically engineered microbes |url=http://en.cnki.com.cn/Article_en/CJFDTOTAL-HDKC200601013.htm |journal=Entomological Journal of East China |issue=1 |pages=53–8 |volume=15}}</ref><ref name="Kolsto-et-al-2009" /> If these plasmids are lost it becomes indistinguishable from ''B. cereus'' as ''B. thuringiensis'' has no other species characteristics. Plasmid exchange has been observed both naturally and experimentally both within ''B.t.'' and between ''B.t.'' and two congeners, ''B. cereus'' and ''B. mycoides''.<ref name="Kolsto-et-al-2009" />

[[plcR]] is an indispensable [[transcription regulator]] of most [[virulence factors]], its absence greatly reducing virulence and toxicity. Some strains do naturally complete their life cycle with an inactivated plcR. It is half of a two-gene [[operon]] along with the [[heptapeptide]] {{visible anchor|papR}}. papR is part of [[quorum sensing]] in ''B. thuringiensis''.<ref name="Kolsto-et-al-2009" />

Various strains including [[Bacilus thuringiensis var. kurstaki ATCC 33679|''Btk'' ATCC 33679]] carry plasmids belonging to the wider [[pXO1-like plasmid|pXO1-like family]]. (The pXO1 family being a ''B. cereus''-common family with members of ≈330kb length. They differ from pXO1 by replacement of the pXO1 [[pathogenicity island]].) The insect parasite [[Bacilus thuringiensis var. kurstaki HD73|''Btk'' HD73]] carries a [[pXO2-like plasmid]] ([[pBT9727]]) lacking the 35kb pathogenicity island of pXO2 itself, and in fact having no identifiable virulence factors. (The pXO2 family does not have replacement of the pathogenicity island, instead simply lacking that part of pXO2.)<ref name="Kolsto-et-al-2009" />

The genomes of the ''B. cereus'' group may contain two types of [[intron]]s, dubbed group I and group II. ''B.t'' strains have variously 0–5 group Is and 0–13 group IIs.<ref name="Kolsto-et-al-2009" />

There is still insufficient information to determine whether chromosome-plasmid [[coevolution]] to enable adaptation to particular environmental niches has occurred or is even possible.<ref name="Kolsto-et-al-2009" />

Common with ''B. cereus'' but so far not found elsewhere – including in other members of the species group – are the [[efflux pump]] [[BC3663]], the [[N-acyl-L-amino-acid amidohydrolase|''N''-acyl-{{small|L}}-amino-acid amidohydrolase]] [[BC3664]], and the [[methyl-accepting chemotaxis protein]] [[BC5034]].<ref name="Kolsto-et-al-2009" />