Romstad A, Gasser R B, Nansen P, Polderman A M, Chilton N B
Department of Veterinary Science, University of Melbourne, Werribee, Victoria, Australia.
Int J Parasitol. 1998 Apr;28(4):611-5. doi: 10.1016/s0020-7519(97)00213-0.
The nucleotide sequences of the second internal transcribed spacer of rDNA were determined for adult worms of Necator americanus originating from Togo (Africa) and Sarawak (Malaysia). The length of the sequences of specimens from Togo (325 bp) were shorter than those from Sarawak (327 bp). There were six fixed genetic differences in the aligned sequences of N. americanus from Sarawak and Togo, excluding one or two polymorphic sites within the sequence of N. americanus from each geographical region. These findings suggest that there is either population variation in the sequence of N. americanus, or that N. americanus from the two countries may represent genetically distinct but morphologically similar (i.e. cryptic) species, however, comparison of the sequence differences among other hookworm species supports the latter conclusion.
测定了来自多哥（非洲）和砂拉越（马来西亚）的美洲板口线虫成虫核糖体DNA第二内部转录间隔区的核苷酸序列。来自多哥的标本序列长度（325bp）比来自砂拉越的标本序列长度（327bp）短。在来自砂拉越和多哥的美洲板口线虫比对序列中存在六个固定的遗传差异，每个地理区域的美洲板口线虫序列内排除一两个多态性位点。这些发现表明，美洲板口线虫序列要么存在种群变异，要么来自这两个国家的美洲板口线虫可能代表基因上不同但形态相似（即隐性）的物种，然而，其他钩虫物种之间序列差异的比较支持后一种结论。
