Schwenkenbecher J M, Kaplan R M
Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
Parasitol Res. 2007 Apr;100(5):1015-21. doi: 10.1007/s00436-006-0367-9. Epub 2006 Nov 29.
Microsatellites are repetitive genomic elements that show high levels of variation and therefore provide excellent tools to study the genetics of eukaryotic organisms. Hookworms are extremely common and important nematode parasites of humans and animals, causing potentially serious disease morbidity. Control of hookworms in dogs is achieved by frequent treatment with anthelmintics, and in humans, anthelmintics are frequently administered in a mass-treatment community-wide approach. Understanding the population genetics of hookworms has important implications for studies on the development and spread of drug resistance. We investigated the genome of Ancylostoma caninum for microsatellites by developing and then screening an enriched genomic library as well as by data mining published sequences of a whole genome shotgun library. Investigations revealed a high abundance of trinucleotide repeats. Dinucleotide repeats were characterized by a high number of AT, GA, and GT repeats. After testing and optimization of 68 markers, a panel of 34 polymorphic microsatellite markers were selected. Microsatellite analysis of hookworm isolates revealed a high degree of polymorphism, which was not influenced by the length of the repeats. This panel of microsatellite markers makes it possible to pursue investigations on the population genetics of A. caninum. Furthermore, a number of the markers demonstrated suitability for analysis of the human hookworm species Necator americanus and A. duodenale.
微卫星是重复性基因组元件，表现出高度的变异性，因此为研究真核生物的遗传学提供了出色的工具。钩虫是人和动物极为常见且重要的线虫寄生虫，可导致潜在的严重疾病发病率。犬类钩虫的控制通过频繁使用驱虫药来实现，而在人类中，驱虫药通常以社区范围内的群体治疗方式给药。了解钩虫的群体遗传学对耐药性的发展和传播研究具有重要意义。我们通过构建并筛选一个富集基因组文库以及挖掘已发表的全基因组鸟枪法文库序列，对犬钩虫基因组进行了微卫星研究。研究发现三核苷酸重复序列高度丰富。二核苷酸重复序列的特征是大量的AT、GA和GT重复。在对68个标记进行测试和优化后，选择了一组34个多态性微卫星标记。对钩虫分离株的微卫星分析显示出高度的多态性，且不受重复序列长度的影响。这组微卫星标记使得对犬钩虫群体遗传学的研究成为可能。此外，一些标记显示适用于分析人钩虫种类美洲板口线虫和十二指肠钩口线虫。
