Roos Marleen H, Otsen Myrthe, Hoekstra Ruurdtje, Veenstra Jetty G, Lenstra Johannes A
Department of Molecular Recognition, Institute for Animal Science and Health (ID-Lelystad), Lelystad, The Netherlands.
Int J Parasitol. 2004 Jan;34(1):109-15. doi: 10.1016/j.ijpara.2003.10.002.
Haemonchus contortus is a sheep parasitic nematode that causes severe economic losses. Previous studies have indicated a high degree of genetic heterogeneity, which is hardly affected by selection for drug resistance. As a tool for the analysis of the population dynamics of H. contortus and its response to drug resistance, we designed a strategy to study the inbreeding of a benzimidazole-sensitive and a benzimidazole-resistant strain. After 15 generations, a theoretical inbreeding coefficient of 0.87 was achieved. The different stages of inbreeding were analysed using restriction fragment polymorphism, microsatellite variability and amplified fragment length polymorphism. Model-based clustering of the amplified fragment length polymorphism genotypes showed that the allele frequencies of the benzimidazole-resistant strain were stable during the last eight generations. In the sensitive strain a gradual shift of allele frequencies was observed, which led to a temporary increase of the genetic diversity around the eight generations.
捻转血矛线虫是一种寄生于绵羊的线虫，会造成严重的经济损失。以往研究表明，该线虫具有高度的遗传异质性，几乎不受耐药性选择的影响。作为分析捻转血矛线虫种群动态及其对耐药性反应的工具，我们设计了一项策略来研究苯并咪唑敏感株和耐药株的近亲繁殖情况。经过15代后，理论近亲繁殖系数达到了0.87。利用限制性片段多态性、微卫星变异性和扩增片段长度多态性对近亲繁殖的不同阶段进行了分析。基于模型的扩增片段长度多态性基因型聚类分析表明，耐药株的等位基因频率在最后八代中保持稳定。在敏感株中，观察到等位基因频率逐渐变化，这导致在大约八代时遗传多样性暂时增加。
