Méndez-Sánchez Daniel, Mayén-Estrada Rosaura, Luo Xiaotian, Hu Xiaozhong
Laboratorio de Protozoología, Facultad de Ciencias, Universidad Nacional Autónoma de México, Circuito Ext. s/núm. Ciudad Universitaria, Av. Universidad 3000, Coyoacán, 04510, Ciudad de México, Mexico.
Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003, China.
J Eukaryot Microbiol. 2018 May;65(3):357-371. doi: 10.1111/jeu.12479. Epub 2017 Nov 10.
The genus Oxytricha Bory de Saint-Vincent in Lamouroux, Bory de Saint-Vincent and Deslongchamps, 1824 comprises about 38 species distributed worldwide and has been considered to be a nonmonophyletic group. Based on living observations, protargol preparations, and a small subunit ribosomal RNA (SSU rRNA) gene sequence, we describe a new subspecies Oxytricha granulifera chiapasensis n. subsp. This new taxon is morphologically characterized by undulating membranes basically in a Stylonychia-pattern, six dorsal kineties, size in vivo ca. 60-120 × 20-40 μm, 21-30 right and 21-31 left marginal cirri, 22-29 adoral membranelles, and spherical cortical granules arranged in longitudinal rows on the dorsal side. In terms of the SSU rRNA gene sequence, the new subspecies differs from populations of O. granulifera from GENBANK by 7-35 nucleotides. Phylogenetic analyses showed that Oxytricha granulifera gene sequences were nested into three groups, with the new subspecies included in one of them. Oxytricha granulifera chiapasensis n. subsp. is different from Oxytricha granulifera granulifera Foissner and Adam, 1983 and Oxytricha granulifera quadricirrata Blatterer and Foissner, 1988 based on: (i) undulating membranes in Stylonychia-pattern, (ii) formation of a sixth dorsal kinety during morphogenesis, (iii) the adoral membranelles number, and (iv) inhabiting freshwater habitats.
1824年，拉穆鲁、博里·德·圣-文森特和德龙尚普斯所描述的尖毛虫属（Oxytricha）由博里·德·圣-文森特创立，包含约38个分布于世界各地的物种，被认为是一个非单系类群。基于活体观察、原银染制片以及小亚基核糖体RNA（SSU rRNA）基因序列，我们描述了一个新亚种，即恰帕斯尖毛虫（Oxytricha granulifera chiapasensis）新亚种。这个新分类单元在形态上的特征为波动膜基本呈硬毛虫模式，有六条背纤毛列，活体大小约为60 - 120×20 - 40μm，右侧有21 - 30根缘毛，左侧有21 - 31根缘毛，22 - 29片口围膜，以及在背面呈纵向排列的球形皮层颗粒。就SSU rRNA基因序列而言，该新亚种与GENBANK中尖毛虫属其他种群的序列相差7 - 35个核苷酸。系统发育分析表明，尖毛虫属的基因序列嵌套在三个组中，新亚种包含在其中一组。恰帕斯尖毛虫新亚种与1983年福斯纳和亚当描述的颗粒尖毛虫（Oxytricha granulifera granulifera）以及1988年布拉特勒和福斯纳描述的四列尖毛虫（Oxytricha granulifera quadricirrata）不同，基于以下几点：（i）波动膜呈硬毛虫模式；（ii）形态发生过程中形成第六条背纤毛列；（iii）口围膜数量；（iv）栖息于淡水生境。
