Young A S, Dolan T T, Mwakima F N, Ochanda H, Mwaura S N, Njihia G M, Muthoni M W, Dolan R B
International Livestock Research Institute, Nairobi, Kenya.
Parasitology. 1995 Jul;111 ( Pt 1):31-8. doi: 10.1017/s003118200006457x.
Heritability of susceptibility to infection with Theileria parva was estimated from full sib families of Rhipicephalus appendiculatus ticks. Male and female ticks of 2 stocks were mated singly. Nineteen full sib families of the Muguga stock and 17 full sib families of the Kiambu stock were obtained. Nymphae of these families were fed on cattle infected with T. parva so that the ticks became replete on days 16 and 17 after infection when the blood was parasitaemic with intraerythrocytic piroplasms. The T. parva infections were assessed in the resultant adult ticks of each full sib group and the abundance of infection, the number of salivary gland acini infected/tick, was found to be the most useful parameter for analysis. Estimates of heritability of the susceptibility to infection with T. parva for the Kiambu and the Muguga tick stocks were 0.24 and 0.26 respectively. Using only the data from ticks which fed on day 16, the heritability estimates were 0.39 for the Kiambu stock and 0.59 for the Muguga stock. These results indicate that tick lines of high or low susceptibility for T. parva infection could be produced through selection.
从微小牛蜱的全同胞家系中估计了对小泰勒虫感染易感性的遗传力。将2个种群的雄性和雌性蜱单独交配。获得了穆古加种群的19个全同胞家系和基安布种群的17个全同胞家系。这些家系的若虫以感染小泰勒虫的牛为食，以便蜱在感染后第16天和第17天饱血，此时血液中含有红细胞内梨形虫。在每个全同胞组的成年蜱中评估小泰勒虫感染情况，发现感染丰度，即每只蜱感染的唾液腺腺泡数量，是最有用的分析参数。基安布和穆古加蜱种群对小泰勒虫感染易感性的遗传力估计分别为0.24和0.26。仅使用在第16天进食的蜱的数据，基安布种群的遗传力估计为0.39，穆古加种群为0.59。这些结果表明，通过选择可以培育出对小泰勒虫感染易感性高或低的蜱品系。
