Genetic diversity among Toxoplasma gondii strains from different hosts and geographical regions revealed by sequence analysis of GRA5 gene.
Genetic diversity among Toxoplasma gondii strains from different hosts and geographical regions revealed by sequence analysis of GRA5 gene.
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DOI：
10.1186/1756-3305-5-279
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发表时间：
2012-12-03
影响因子：
3.2
通讯作者：
Zhu XQ
中科院分区：
文献类型：
--
作者：
Chen J;Li ZY;Zhou DH;Liu GH;Zhu XQ
弓形虫是一种高度流行的原生动物寄生虫，广泛感染动物和人类。弓形虫的流行病学和生物多样性导致了这种寄生虫高度的遗传变异和不寻常的种群结构。本研究检测了不同宿主和不同地理区域的弓形虫致密颗粒5(GRA5)基因的序列多样性。对14株弓形虫GRA5基因全基因组序列进行了扩增和测序，并根据GRA5基因序列用贝叶斯推理和最大简约度方法重建了这些弓形虫分离株之间的系统发育关系。TgCatBr5和MAS的GRA5基因全长为1614个碱基，其余12个菌株为1617个碱基。序列分析在所有分离株中鉴定出41个(0-1.7%)可变核苷酸位置，其中18个变异位于编码区。TgCatBr5和MAS的编码区变异导致11个氨基酸替换，3个碱基缺失导致1个氨基酸缺失。序列变异导致了AatII和MluI酶切位点的多态，从而使PCR-RFLP可以区分出I、II和III三种主要克隆谱系类型。用BI和MP进行的系统发育分析支持将被检查的弓形虫菌株明确地区分为各自的基因类型。本研究证实了不同宿主和不同地理区域的弓形虫分离株GRA5基因序列存在一定的序列变异，这使得所研究的弓形虫分离株可以分化为各自的基因类型，这一高度多态的GRA5基因座可能为弓形虫分离株的群体遗传学研究提供一个新的遗传标记。
Toxoplasma gondii is a highly prevalent protozoan parasite infecting a wide range of animals and humans. The epidemiological and biological diversity of T. gondii has resulted in a high genetic variation and unusual population structure in this parasite. This study examined sequence diversity in dense granule 5 (GRA5) gene among T. gondii isolates from different hosts and geographical regions. The entire genome region of the GRA5 gene was amplified and sequenced from 14 T. gondii isolates, and phylogenetic relationship among these T. gondii isolates was reconstructed using Bayesian inference (BI) and maximum parsimony (MP) based on the GRA5 sequences. The complete sequence of the GRA5 gene was 1614 bp in length for strains TgCatBr5 and MAS, but 1617 bp for the other 12 strains. Sequence analysis identified 41 (0–1.7%) variable nucleotide positions among all isolates, with 18 variations of these being in the coding region. Variable positions in the coding region resulted in 11 amino acid substitutions, and a deletion of 3 bp in the strains TgCatBr5 and MAS leading to the deletion of one amino acid. Sequence variations resulted in the existence of polymorphic restriction sites for endonucleases AatII and MluI, allowing the differentiation of the three major clonal lineage types I, II and III by PCR-RFLP. Phylogenetic analyses using BI and MP supported the clear differentiation of the examined T. gondii strains into their respective genotypes. This study demonstrated the existence of sequence variability in the GRA5 gene sequence among T. gondii isolates from different hosts and geographical regions, which allowed the differentiation of the examined T. gondii strains into their respective genotypes, suggesting that this highly polymorphic GRA5 locus may provide a new genetic marker for population genetic studies of T. gondii isolates.
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影响因子：
1.5
作者：
Mercier, C;Rauscher, B;Cesbron-Delauw, MF
通讯作者：
Cesbron-Delauw, MF
影响因子：
5.8
作者：
Morisset, Stephane;Peyron, Francois;Cesbron-Delauw, Marie-France
通讯作者：
Cesbron-Delauw, Marie-France
影响因子：
6.4
作者：
Kong, JT;Grigg, ME;Boothroyd, JC
通讯作者：
Boothroyd, JC
影响因子：
4
作者：
Fazaeli, A;Carter, PE;Pennington, TH
通讯作者：
Pennington, TH
影响因子：
1.3
作者：
Huang, Si-Yang;Cong, Wei;Zhu, Xing-Quan
通讯作者：
Zhu, Xing-Quan