Blok V C, Phillips M S, Fargette M
J Nematol. 1997 Mar;29(1):16-22.
The unusual arrangement of the 5S ribosomal gene within the intergenic sequence (IGS) of the ribosomal cistron, previously reported for Meloidogyne arenaria, was also found in the ribosomal DNA of two other economically important species of tropical root-knot nematodes, M, incognita and M. javanica. This arrangement also was found in M. hapla, which is important in temperate regions, and M. mayaguensis, a virulent species of concern in West Africa. Amplification of the region between the 5S and 18S genes by PCR yielded products of three different sizes such that M. mayaguensis could be readily differentiated from the other species in this study. This product can be amplified from single juveniles, females, or egg masses. The sequences obtained in this region for one line of each of M. incognita, M. arenaria, and M. javanica were very similar, reflecting the close relationships of these lineages. The M. mayaguensis sequence for this region had a number of small deletions and insertions of various sizes, including possible sequence duplications.
5S核糖体基因在核糖体顺反子的基因间序列（IGS）中的异常排列，先前已在南方根结线虫中报道过，在另外两种具有重要经济意义的热带根结线虫——爪哇根结线虫和花生根结线虫的核糖体DNA中也被发现。这种排列在温带地区具有重要意义的北方根结线虫以及西非令人关注的致病物种玛雅根结线虫中也被发现。通过聚合酶链反应（PCR）扩增5S和18S基因之间的区域，产生了三种不同大小的产物，因此在本研究中玛雅根结线虫可以很容易地与其他物种区分开来。该产物可以从单个幼虫、雌虫或卵块中扩增出来。在本研究中，从南方根结线虫、花生根结线虫和爪哇根结线虫的每个品系的该区域获得的序列非常相似，这反映了这些谱系之间的密切关系。玛雅根结线虫该区域的序列有许多不同大小的小缺失和插入，包括可能的序列重复。
