Relationships among members of the genus Myxobolus (Myxozoa: Bilvalvidae) based on small subunit ribosomal DNA sequences
Relationships among members of the genus Myxobolus (Myxozoa: Bilvalvidae) based on small subunit ribosomal DNA sequences
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DOI：
10.2307/3285702
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发表时间：
1999-02-01
影响因子：
1.3
通讯作者：
Hedrick, RP
中科院分区：
文献类型：
--
作者：
Andree, KB;Székely, C;Hedrick, RP
从粘虫属（Myxobulus）的10个不同物种中发现了类似于1700个碱基对的18S rRNA基因序列，将它们归为3个簇，这些簇与孢子形态和大小或宿主特异性（目前用于粘虫属中较高和较低分类位置的标准）几乎没有相关性。在检查的表型标准中，组织趋向性与观察到的rRNA分组最相关。大小和形状相似的孢子（Myxobolus cerebralis和Myxobolus squamalis）在某些情况下是远亲，而形态和大小不同的孢子（M. cerebralis和Myxobolus insidiosus）有时是近亲。这些对黏液菌属推定成员系统发育关系的初步调查清楚地表明，根据孢子和受感染宿主物种的大小和形态特征进行分组的潜在局限性。我们建议18S rRNA基因序列，结合组织趋向性、感染宿主物种以及鱼类和交替宿主（当和如果知道）的发育周期信息，在粘孢子虫的分类定位中给予更多的考虑。
Sequences representing similar to 1,700 base pairs of the 18S rRNA gene from 10 different species in the genus Myxobulus were found to group them into 3 clusters that showed little correlation with spore morphology and size or host specificity, criteria currently used for both higher and lower taxonomic placements in the Myxozoa. Of the phenotypic criteria examined, tissue tropism was most correlated with the rRNA groupings observed. Spores of similar size and shape (Myxobolus cerebralis vs. Myxobolus squamalis) were distantly related in some instances, whereas spores with divergent morphology and size were some times found to be closely related (M. cerebralis and Myxobolus insidiosus). These initial investigations into the phylogenetic relationships of putative members of the genus Myxobolus clearly indicate the potential limitations of groupings based on size and morphological properties of the spores and host species infected. We propose that 18S rRNA gene sequences, combined with information on tissue tropism, host species infected, and developmental cycles in the fish and alternate host (when and if known) be given greater consideration in taxonomic placements of myxosporeans.