Beveridge I, Chilton N B, Andrews R H
Department of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia.
Int J Parasitol. 1993 Feb;23(1):21-33. doi: 10.1016/0020-7519(93)90094-f.
Macropostrongyloides baylisi from four different species or subspecies of host were analysed electrophoretically at 27 enzyme loci. The results revealed the existence of two species, one in Macropus giganteus and the other in M. robustus robustus, M.r. erubescens and M.r. parryi, that had fixed genetic differences at 33% of loci. Populations of nematodes from two subspecies of M. robustus, M.r. robustus from Queensland and M.r. erubescens from South Australia, had fixed genetic differences at two (7.4%) of 27 loci and were considered to belong to the same species. No fixed genetic differences were detected between nematodes from M. parryi and M.r. robustus. A discriminant function analysis of morphological data assigned 96% of specimens to groups defined on the basis of the host species or subspecies from which they were obtained. This separation of Ma. baylisi into host-specific groups did not, however, totally correlate with the electrophoretic data. The species of M. baylisi in M. giganteus was genetically more distinct from the sibling species in M. robustus/M. parryi than to a related but morphologically dissimilar nematode, Ma. yamagutii from M. fuliginosus. This suggests an evolutionary parallel between host and parasite at the genetic level which is not reflected by morphological differences.
对来自四种不同宿主物种或亚种的贝氏巨圆线虫在27个酶位点进行了电泳分析。结果显示存在两个物种，一个存在于巨袋鼠中，另一个存在于粗壮袋鼠指名亚种、粗壮袋鼠赤褐亚种和粗壮袋鼠帕里亚种中，它们在33%的位点上存在固定的遗传差异。来自粗壮袋鼠两个亚种的线虫种群，即来自昆士兰的粗壮袋鼠指名亚种和来自南澳大利亚的粗壮袋鼠赤褐亚种，在27个位点中的两个位点（7.4%）上存在固定的遗传差异，被认为属于同一物种。在来自帕里袋鼠和粗壮袋鼠指名亚种的线虫之间未检测到固定的遗传差异。对形态学数据的判别函数分析将96%的标本归入根据其来源的宿主物种或亚种定义的组中。然而，贝氏巨圆线虫分为宿主特异性组的情况与电泳数据并不完全相关。巨袋鼠中的贝氏巨圆线虫物种在遗传上与粗壮袋鼠/帕里袋鼠中的姐妹物种相比，与来自烟色袋鼠的相关但形态不同的线虫山古氏巨圆线虫更为不同。这表明在遗传水平上宿主和寄生虫之间存在进化平行关系，而形态差异并未反映这一点。
