Guillemin Isabelle, Bouchier Christiane, Garrigues Thomas, Wisner Anne, Choumet Valérie
Unité des Venins, Institut Pasteur, Paris, France.
Eur J Biochem. 2003 Jul;270(13):2697-706. doi: 10.1046/j.1432-1033.2003.03629.x.
We used a PCR-based method to determine the genomic DNA sequences encoding phospholipases A2 (PLA2s) from the venoms of Vipera aspis aspis (V. a. aspis), Vipera aspis zinnikeri (V. a. zinnikeri), Vipera berus berus (V. b. berus) and a neurotoxic V. a. aspis snake (neurotoxic V. a. aspis) from a population responsible for unusual neurotoxic envenomations in south-east France. We sequenced five groups of genes, each corresponding to a different PLA2. The genes encoding the A and B chains of vaspin from the neurotoxic V. a. aspis, PLA2-I from V. a. zinnikeri, and the anticoagulant PLA2 from V. b. berus are described here. Single nucleotide differences leading to amino-acid substitutions were observed both between genes encoding the same PLA2 and between genes encoding different PLA2s. These differences were clustered in exons 3 and 5, potentially altering the biological activities of PLA2. The distribution and characteristics of the PLA2 genes differed according to the species or subspecies. We characterized for the first time genes encoding neurotoxins from the V. a. aspis and V. b. berus snakes of central France. Genes encoding ammodytins I1 and I2, described previously in Vipera ammodytes ammodytes (V. am. ammodytes), were also present in V. a. aspis and V. b. berus. Three different ammodytin I1 gene sequences were characterized: one from V. b. berus, the second from V. a. aspis, V. a. zinnikeri and the neurotoxic V. a. aspis, and the third from the neurotoxic V. a. aspis. This third sequence was identical with the reported sequence of the V. am. ammodytes ammodytin I1 gene. Genes encoding monomeric neurotoxins of V. am. ammodytes venom, ammodytoxins A, B and C, and the Bov-B LINE retroposon, a phylogenetic marker found in V. am. ammodytes genome, were identified in the genome of the neurotoxic V. a. aspis. These results suggest that the population of neurotoxic V. a. aspis snakes from south-east France may have resulted from interbreeding between V. a. aspis and V. am. ammodytes.
我们采用基于聚合酶链反应（PCR）的方法，来确定编码磷脂酶A2（PLA2s）的基因组DNA序列，这些磷脂酶A2来自极北蝰（Vipera aspis aspis，简称V. a. aspis）、津氏极北蝰（Vipera aspis zinnikeri，简称V. a. zinnikeri）、贝氏蝰（Vipera berus berus，简称V. b. berus）的毒液，以及一条来自法国东南部、具有神经毒性的极北蝰蛇（神经毒性极北蝰），该种群导致了异常的神经毒性中毒事件。我们对五组基因进行了测序，每组对应一种不同的PLA2。本文描述了来自神经毒性极北蝰的vaspin A链和B链、来自津氏极北蝰的PLA2-I，以及来自贝氏蝰的抗凝PLA2的编码基因。在编码相同PLA2的基因之间以及编码不同PLA2的基因之间，均观察到导致氨基酸替换的单核苷酸差异。这些差异集中在外显子3和5中，可能会改变PLA2的生物学活性。PLA2基因的分布和特征因物种或亚种而异。我们首次对来自法国中部的极北蝰和贝氏蝰蛇的神经毒素编码基因进行了表征。先前在矛头蝮（Vipera ammodytes ammodytes，简称V. am. ammodytes）中描述的编码沙海蝰素I1和I2的基因，在极北蝰和贝氏蝰中也存在。我们鉴定出了三种不同的沙海蝰素I1基因序列：一种来自贝氏蝰，第二种来自极北蝰、津氏极北蝰和神经毒性极北蝰，第三种来自神经毒性极北蝰。这第三种序列与已报道的矛头蝮沙海蝰素I1基因序列相同。在神经毒性极北蝰的基因组中，鉴定出了编码矛头蝮毒液单体神经毒素、沙海蝰毒素A、B和C的基因，以及Bov - B LINE反转录转座子，这是在矛头蝮基因组中发现的一种系统发育标记。这些结果表明，来自法国东南部的神经毒性极北蝰蛇种群可能是极北蝰和矛头蝮杂交的结果。
