D型肉毒毒素灭鼠剂对棕背雪雀危害机理的试验研究

Experimental Study on the Damage Mechanism of Type D Botulinum Toxin Rodenticide to the Plain-Backed Snowfinch

以大白鼠(Rattus norvegicus)与高原鼠兔(Ochotona curzoniae)为对照组,分别开展D型肉毒神经毒素对高原鸟类棕背雪雀(Pyrgilauda blanfordi)灌胃半数致死量(LD_(50))、胃肠内容物对D型肉毒毒素蛋白的破坏强度,以及棕背雪雀、高原鼠兔、高原鼢鼠(Myospalax baileyi)和青海田鼠(Lasiopodomys fuscus)体内VAMP1蛋白转录组测序分析,试图探析D型肉毒毒素生物灭鼠剂对高原牧区环境动物的安全性差异产生的机理,以及对高原牧区生境中与高原鼠兔同穴而居的棕背雪雀的危害程度。结果显示:棕背雪雀对D型肉毒毒素的敏感性介于高原鼢鼠与青海田鼠之间,LD_(50)为2.71万~3.16万MLD/kg(95%可信限为1.69万~4.88万MLD/kg);大白鼠胃肠内容物对D型肉毒毒素的破坏强度明显高于高原鼠兔及棕背雪雀;在基因编码区序列推导的氨基酸序列水平上,棕背雪雀体内的VAMP1氨基酸序列(GenBank No.GQ905710)与昆明系小鼠完全相同,VAMP1氨基酸序列在第48号氨基酸位点(为48M型,而非48Ⅰ型)属于D型肉毒毒素敏感型氨基酸,表明棕背雪雀对D型肉毒毒素具有一定的敏感性,在现地鼠害防治中应精准控制鼠药投放剂量,建议采取药物警戒色趋避鸟类食毒饵。

Using rat(Rattus norvegicus)and plateau pika(Ochotona curzoniae)as control groups,the median lethal dose(LD_(50))of type D botulinum neurotoxin to plateau bird plain-backed snowfinch(Pyrgilauda blanfordi)and the destruction intensity of type D botulinum toxin protein by gastrointestinal contents were determined;in addition to that,transcriptome sequencing analysis of VAMP1 protein in plain-backed snowfinch,plateau pika,plateau zokor(Myospalax baileyi)and Qinghai vole(Lasiopodomys fuscus)were conducted;and then we explored the mechanism of difference in the safety of type D botulinum rodenticide on animals,as well as the degree of harm to the plain-backed snowfinch sharing the same burrow with the plateau pika in the plateau pastoral habitat.The results showed that the sensitivity of the plain-backed snowfinch to botulinum toxin type D was in between plateau zokor and Qinghaivole.The median lethal dose ranged from 27,100 to 31,600 MLD/kg body weight(95%confidence limit was 16,900 to 48,800 MLD/kg body weight).The gastrointestinal contents of rats had a significantly stronger damage on botulinum toxin D than that of the plateau pika and plain-backed snowfinch.The Illumina Hiseq high-throughput sequencing platform was used to sequence and assemble the cDNA library.The amino acid sequence of VAMP1(GenBank No.GQ905710)in the plain-backed snowfinch was exactly the same as that of mice at the level of the deduced amino acid sequence of the gene coding region sequence,and the amino acid sequence of VAMP1 was at the 48th amino acid position(type 48M,not type 48I)which was a type D botulinum toxin-sensitive amino acid.The plain-backed snowfinch in plateau pastoral areas had a certain level of sensitivity to type D botulinum toxin.The dose of rodenticides should be precisely controlled in the current rodent control,and it is recommended to take pharmacovigilance to avoid birds from foraging poison baits.