The diversity of gas vesicle genes in Planktothrix rubescens from Lake Zurich
The diversity of gas vesicle genes in Planktothrix rubescens from Lake Zurich
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DOI：
10.1099/00221287-145-10-2757
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发表时间：
1999-10-01
期刊：
影响因子：
2.8
通讯作者：
Walsby, AE
中科院分区：
文献类型：
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作者：
Beard, SJ;Handley, BA;Walsby, AE
用PCR方法从瑞士苏黎世湖分离的3株乳杆菌中扩增出部分气体囊泡基因簇。每个包含多个gvpA和gvpC的交替副本。不同菌株的gvpA序列完全相同。gvpC有两种类型：gvpC（20）全长516 bp，编码一个含有172个氨基酸残基的20 kDa蛋白（其n端氨基酸序列与浮游thrix[振荡]agardhii中的gvpC序列同源）；gvpC（16）全长417 bp，编码一个含有139个氨基酸残基的16 kDa蛋白，其不同之处在于缺少一个内部33个残基区段。在一些菌株中也存在来自gvpC 3'端未翻译的72bp片段，称为Omega C。利用与gvpC和gvpA内部序列同源的对寡核苷酸引物获得的PCR扩增产物长度不同，可以区分两种类型的gvpC和Omega C的存在。发现了3种基因型：GV1，只含有gvpC(20)；GV2，含gvpC（20）和Omega C；GV2和GV3的亚类含有一个或两个Omega c的拷贝。d.i， Bright和a.e. Walsby（微生物学145,2769-2775）的论文表明，GV3基因型的菌株产生的气体囊泡的临界压力高于GV1和GV2。从苏黎世湖分离的185株克隆培养物进行PCR分析，结果显示3株为GV1基因型，73株为GV2基因型，109株为GV3基因型。采用PCR技术对从湖水样品中选取的单丝进行气囊基因型和相关临界压力表型的区分。对16S rDNA和编码藻红蛋白、藻蓝蛋白和Rubisco的操纵子区域的序列分析证实，这些浮游菌属形成了一个紧密的系统发育群。
Part of the gas vesicle gene cluster was amplified by PCR from three strains of Planktothrix rubescens isolated from Lake Zurich, Switzerland. Each contains multiple alternating copies of gvpA and gvpC. All of the gvpA sequences in the different strains are identical. There are two types of gvpC: gvpC(20), of length 516 bp, encodes a 20 kDa protein of 172 amino acid residues (whose N-terminal amino acid sequence is homologous with the sequence of GvpC in Planktothrix [Oscillatoria] agardhii); gvpC(16), of length 417 bp, encodes a 16 kDa protein of 139 amino acid residues that differs in lacking an internal 33-residue section. An untranslated 72 bp fragment from the 3' end of gvpC, designated Omega C, is also present in some strains. The two types of gvpC and presence of Omega C could be distinguished by the different lengths of PCR amplification products obtained using pairs of oligonucleotide primers homologous to internal sequences in gvpC and gvpA. Three genotype classes were found: GV1, containing only gvpC(20); GV2, containing gvpC(20) and Omega C; and GV3, containing gvpC(16), gvpC(20) and Omega cC. Subclasses of GV2 and GV3 contained either one or two copies of Omega C. The accompanying paper by D. I, Bright & A. E. Walsby (Microbiology 145, 2769-2775) shows that strains of the GV3 genotype produce gas vesicles with a higher critical pressure than those of GV1 and GV2. A PCR survey of 185 clonal cultures of P. rubescens isolated from Lake Zurich revealed that 3 isolates were of genotype GV1, 73 were of GV2 and 109 were of GV3. The PCR technique was used to distinguish the gas vesicle genotype, and thence the associated critical-pressure phenotype, of single filaments selected from lakewater samples. Sequence analysis of the 16S rDNA and of regions within the operons encoding phycoerythrin, phycocyanin and Rubisco confirmed that these strains of Planktothrix form a tight phylogenetic group.