Stear M J, Murray M
University of Glasgow Veterinary School, Bearsden, UK.
Vet Parasitol. 1994 Aug;54(1-3):161-76. doi: 10.1016/0304-4017(94)90089-2.
There is substantial variation among individuals in susceptibility to a wide variety of parasitic diseases and part of this variation in susceptibility is due to genetic factors. The challenge now is to determine the best methods of using the variation to improve our understanding of parasitic infection and to reduce the ravages of parasitic disease. Scientific and commercial applications will depend upon the type of genetic variation. Variation among breeds can be easily exploited by a policy of breed substitution. Variation within a breed can be exploited by selective breeding to improve resistance to infection or to disease, but more work is needed to develop selection indices which are acceptable to livestock breeders. Identifying genes which contribute to the variation in resistance provides a better understanding of the mechanisms of resistance but more work is needed to determine if such genes, alone or in combination, account for a sufficient proportion of the variation in resistance to allow marker assisted selection. A comparison of responses in susceptible and resistant stock provides a powerful tool to distinguish among protective, irrelevant and pathological responses. These themes have been illustrated by three studies of gastrointestinal nematode infections in ruminants.
个体对多种寄生虫病的易感性存在很大差异，这种易感性差异的部分原因是遗传因素。现在面临的挑战是确定利用这种差异的最佳方法，以增进我们对寄生虫感染的了解，并减少寄生虫病的危害。科学和商业应用将取决于遗传变异的类型。品种间的变异可以通过品种替代策略轻易利用。品种内的变异可以通过选择性育种来利用，以提高对感染或疾病的抵抗力，但需要开展更多工作来开发畜牧养殖者可接受的选择指数。鉴定导致抗性变异的基因有助于更好地理解抗性机制，但需要开展更多工作来确定此类基因单独或组合起来是否能解释抗性变异中足够大的比例，从而实现标记辅助选择。比较易感和抗性群体的反应提供了一个强大的工具，可区分保护性、无关性和病理性反应。反刍动物胃肠道线虫感染的三项研究阐明了这些主题。
