The demise of a phylum of protists: phylogeny of Myxozoa and other parasitic cnidaria.
The demise of a phylum of protists: phylogeny of Myxozoa and other parasitic cnidaria.
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原生生物门的消亡：粘液动物和其他寄生刺胞动物的系统发育。
DOI：
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发表时间：
1995
影响因子：
1.3
通讯作者：
David K. Cone
中科院分区：
文献类型：
--
作者：
M. Siddall;Donald S. Martin;Diane Bridge;S. Desser;David K. Cone
由于这些寄生虫的感染性孢子不是单细胞的，因此经常有人认为，1970年的格拉斯粘虫门成员不属于原生生物分类。系统学家未能对粘体动物系统发育亲缘关系做出决定，要么认为刺胞动物与刺胞动物有联系的建议是荒谬的，要么认为最近与线虫有关系的建议是分子系统发育学的明显失败。因此，该类群本身仍被归类为原生生物门。为了更充分地探索与后生动物类群形态上的共性的可能性，对粘液动物发育的超微结构进行了严格的重新检查。这些形态特征与小核糖体亚基基因序列相结合，用于系统发育分析，以评估粘虫起源。结果明确支持将粘液动物列为高度衍生的寄生刺胞动物的分支，并作为水龙水龙骨的姊妹分类单元。对粘液动物作为后生动物的重新评估揭示了终末分化、典型的后生动物细胞连接和胶原蛋白的产生。它们的“极性胶囊”被重新描述为带有无毛异根的典型刺丝囊。由于类群不能包含在同等级别的其他类群中，粘生动物门被放弃，建议将该类群作为一个整体从所有原生动物分类中删除，并置于更全面的刺胞动物系统中。
The notion that members of the phylum Myxozoa Grassé, 1970 do not properly belong in classifications of protists has frequently been suggested because the infective spores of these parasites are not unicellular. Systematists have failed to be decisive about myxozoan phylogenetic affinities, either finding the suggestion of a cnidarian connection to be preposterous or considering the recent suggestion of a relationship with nematodes to be an obvious failure of molecular phylogenetics. Thus, the group has remained in classifications as a protistan phylum in its own right. The ultrastructure of the development of myxozoans was critically re-examined in order to more fully explore the possibility of morphological synapomorphies with metazoan taxa. These morphological characters, in combination with small ribosomal subunit gene sequences, were used in a phylogenetic analysis in order to assess myxozoan origins. The results unequivocally support the inclusion of myxozoans as a clade of highly derived parasitic cnidarians, and as sister taxon to the narcomedusan Polypodium hydriforme. Reassessment of myxozoans as metazoans reveals terminal differentiation, typical metazoan cellular junctions, and collagen production. Their "polar capsules" are redescribed as typical nematocysts bearing atrichous isorhiza. Insofar as taxa cannot be contained within other taxa of equal rank, the phylum Myxozoa is abandoned and it is recommended that the group as a whole be removed from all protistan classifications and placed in a more comprehensive cnidarian system.
影响因子：
3.5
作者：
MEDLIN, L;ELWOOD, HJ;SOGIN, ML
通讯作者：
SOGIN, ML