title: Gene clusters located on two large plasmids determine spore crystal association (SCA) in Bacillus thuringiensis subsp. finitimus strain YBT-020.
abstract: Crystals in Bacillus thuringiensis are usually formed in the mother cell compartment during sporulation and are separated from the spores after mother cell lysis. In a few strains, crystals are produced inside the exosporium and are associated with the spores after sporulation. This special phenotype, named 'spore crystal association' (SCA), typically occurs in B. thuringiensis subsp. finitimus. Our aim was to identify genes determining the SCA phenotype in B. thuringiensis subsp. finitimus strain YBT-020. Plasmid conjugation experiments indicated that the SCA phenotype in this strain was tightly linked with two large plasmids (pBMB26 and pBMB28). A shuttle bacterial artificial chromosome (BAC) library of strain YBT-020 was constructed. Six fragments from BAC clones were screened from this library and discovered to cover the full length of pBMB26; four others were found to cover pBMB28. Using fragment complementation testing, two fragments, each of approximately 35 kb and located on pBMB26 and pBMB28, were observed to recover the SCA phenotype in an acrystalliferous mutant, B. thuringiensis strain BMB171. Furthermore, deletion analysis indicated that the crystal protein gene cry26Aa from pBMB26, along with five genes from pBMB28, were indispensable to the SCA phenotype. Gene disruption and frame-shift mutation analyses revealed that two of the five genes from pBMB28, which showed low similarity to crystal proteins, determined the location of crystals inside the exosporium. Gene disruption revealed that the three remaining genes, similar to spore germination genes, contributed to the stability of the SCA phenotype in strain YBT-020. Our results thus identified the genes determining the SCA phenotype in B. thuringiensis subsp. finitimus.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Beijing, People's Republic of China.
authors.forename: Yiguang
authors.initials: Y
authors.lastname: Zhu
authors.forename: Fang
authors.initials: F
authors.lastname: Ji
authors.forename: Hui
authors.initials: H
authors.lastname: Shang
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhu
authors.forename: Pengxia
authors.initials: P
authors.lastname: Wang
authors.forename: Chengchen
authors.initials: C
authors.lastname: Xu
authors.forename: Yun
authors.initials: Y
authors.lastname: Deng
authors.forename: Donghai
authors.initials: D
authors.lastname: Peng
authors.forename: Lifang
authors.initials: L
authors.lastname: Ruan
authors.forename: Ming
authors.initials: M
authors.lastname: Sun
mesh_terms: D001413:Bacillus thuringiensis / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D022202:Chromosomes, Artificial, Bacterial; D003001:Cloning, Molecular; D015964:Gene Expression Regulation, Bacterial; D015723:Gene Library; D005810:Multigene Family; D010957:Plasmids / Q000235:genetics*; D013171:Spores, Bacterial / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins
references.citation: J Bacteriol. 1964 Dec;88:1774-89
references.pmid: 14240968
references.citation: Mol Microbiol. 2007 Apr;64(2):359-67
references.pmid: 17493122
references.citation: Gene. 1991 Dec 1;108(1):115-9
references.pmid: 1662180
references.citation: FEMS Microbiol Lett. 2009 Nov;300(1):11-7
references.pmid: 19735465
references.citation: Appl Microbiol Biotechnol. 2009 Mar;82(4):765-72
references.pmid: 19153728
references.citation: J Bacteriol. 2005 Jun;187(11):3800-6
references.pmid: 15901704
references.citation: Appl Environ Microbiol. 2001 Dec;67(12):5362-9
references.pmid: 11722880
references.citation: Appl Environ Microbiol. 2009 Oct;75(19):6410-3
references.pmid: 19648359
references.citation: J Gen Microbiol. 1974 Oct;84(2):261-76
references.pmid: 4615125
references.citation: J Bacteriol. 1991 Sep;173(17):5280-9
references.pmid: 1885511
references.citation: FEBS Lett. 1999 Jun 18;453(1-2):46-8
references.pmid: 10403372
references.citation: Appl Environ Microbiol. 2009 Aug;75(16):5237-43
references.pmid: 19542344
references.citation: J Bacteriol. 2011 May;193(9):2379-80
references.pmid: 21398543
references.citation: Appl Environ Microbiol. 2002 Oct;68(10):5082-95
references.pmid: 12324359
references.citation: J Appl Microbiol. 2009 Jun;106(6):1849-58
references.pmid: 19291242
references.citation: Gene. 1995 Dec 29;167(1-2):335-6
references.pmid: 8566804
references.citation: J Microbiol Biotechnol. 2009 Aug;19(8):749-59
references.pmid: 19734711
references.citation: PLoS One. 2011 Jan 25;6(1):e16025
references.pmid: 21283584
references.citation: J Bacteriol. 2010 Aug;192(15):4074-5
references.pmid: 20525827
references.citation: Annu Rev Microbiol. 2007;61:555-88
references.pmid: 18035610
references.citation: Curr Microbiol. 2003 Jan;46(1):33-8
references.pmid: 12432461
references.citation: J Biophys Biochem Cytol. 1961 Feb;9:285-98
references.pmid: 13711279
references.citation: Microbiol Mol Biol Rev. 1998 Sep;62(3):775-806
references.pmid: 9729609
references.citation: Plasmid. 1998 Jul;40(1):30-43
references.pmid: 9657931
references.citation: Appl Environ Microbiol. 2008 Nov;74(22):6997-7001
references.pmid: 18820056
references.citation: J Bacteriol. 1993 Oct;175(20):6530-6
references.pmid: 8407829
references.citation: J Bacteriol. 1994 May;176(10):2835-45
references.pmid: 7514590
references.citation: Wei Sheng Wu Xue Bao. 2007 Feb;47(1):88-91
references.pmid: 17436631
references.citation: J Bacteriol. 1986 Jan;165(1):258-68
references.pmid: 3001026
references.citation: Appl Environ Microbiol. 1996 Apr;62(4):1306-10
references.pmid: 16535294
references.citation: Cell Mol Life Sci. 2002 Mar;59(3):417-25
references.pmid: 11964120
references.citation: J Biol Chem. 2010 Dec 10;285(50):39191-200
references.pmid: 20864531
references.citation: Appl Environ Microbiol. 2009 Jul;75(14):4661-7
references.pmid: 19465527
references.citation: Appl Environ Microbiol. 2006 Mar;72(3):1771-6
references.pmid: 16517621