Genetic analyses of authentic and alternate forms of Chrysochromulina polylepis (Haptophyta)
Genetic analyses of authentic and alternate forms of Chrysochromulina polylepis (Haptophyta)
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DOI：
10.2216/i0031-8884-37-4-275.1
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发表时间：
1998-07-01
期刊：
影响因子：
1.6
通讯作者：
Medlin, L
中科院分区：
文献类型：
--
作者：
Edvardsen, B;Medlin, L
在1988年在斯卡格拉克和卡特加特发生的有毒水华中，在一些克隆培养物中观察到两种不同的运动细胞类型（真实的和交替的），它们的有机体鳞片形态不同。我们比较了多毛线虫和其他种类多毛线虫的小亚基核糖体DNA （18S SSU rDNA）和第一内部转录间隔区（ITS1）的核苷酸序列，进一步证明了这两种细胞类型都是多毛线虫的形式。从挪威分离的两种细胞类型的菌株在这些基因组区域是相同的，但与英国的c.c.c . polylepis菌株和其他Chrysochromulina物种的菌株不同。通过对钙调蛋白基因内第三个内含子的PCR扩增，在挪威的两种细胞类型中也获得了相似的片段长度，但这些片段长度与英国菌株不同。我们的研究结果表明，这两种细胞类型是同一物种，增加了两种细胞类型在有性单倍体-二倍体生命周期中结合的可能性。其他种类的黄蝇也可能表现出这样的生命周期，这使黄蝇的分类更加复杂。
Two motile cell types (authentic and alternate), differing in their organic body scale morphology, were observed in some clonal cultures of Chrysochromulina polylepis Manton et Parke that originated from the 1988 toxic bloom in Skagerrak and Kattegat. Nucleotide sequences from the small subunit ribosomal DNA (18S SSU rDNA) and the first internal transcribed spacer (ITS1) region from several strains of C. polylepis and from other Chrysochromulina species were compared to provide further evidence that both cell types are forms of C. polylepis. Strains of both cell types isolated from Norway were identical in these genomic regions but differed from those of a British strain of C. cf. polylepis and other Chrysochromulina species. Similar fragment lengths were also obtained for both cell types from Norway from PCR amplification of the third intron within a calmodulin gene, but these differed in length from that of the British strain. Our results suggest that both cell types are the same species, increasing the likelihood that the earlier hypothesis of the two cell types being joined in a sexual haplo-diploid life cycle is valid. Other Chrysochromulina species could display such life cycles, further complicating Chrysochromulina taxonomy.