[来自植物鞭毛虫长眼虫和纤细裸藻的核糖体DNA组织：19S和28S rRNA基因结构的比较]

Zaĭtseva G N, Oparina N Iu, Kagramanova V V, Kleshchenko E V

Mol Biol (Mosk). 1995 May-Jun;29(3):546-52.

Restriction maps of Astasia longa and Euglena gracilis var. bacillaris were built and localization of 5.8S, 19S and 28S rRNA genes was established on them by blot-hybridization method. In the A. longa and E. gracilis plasmid rDNA three intergeneous regions were found, two of which were intergeneous transcribed spacers flanking 5.8S RNA gene, and the third region seems to be an untranscribed spacer. Localization of 9 primers from E. gracilis was established on A. longa 19S rRNA gene by PCR; it was similar to E. gracilis. Using amplified A. longa 19S rRNA gene (2300 bp) we have determined the sequence of its 3'-region, which showed 87% homology with the same region of E. gracilis. Using plasmid pA1 S3-H1 containing S3-H1 fragment of A. longa rDNA the sequence of 28S rRNA gene 3'-region was determined. This sequence includes regions homologous to corresponding regions of E. gracilis Z: 6 nucleotides of 12/13 internal spacer, complete 13/14 internal spacer (86 bp), genes for 13th and 14th 28S rRNA components (56 and 86 bp) with approximately 90% of homology with E. gracilis Z, and fragment of untranscribed spacer (136 bp) with approximately 70% homology. It was shown that 28S rRNA genes of A. longa and E. gracilis have similar structure. Our data allow to conclude that these phytoflagellats are closely related.

构建了长形裸藻（Astasia longa）和纤细裸藻杆状变种（Euglena gracilis var. bacillaris）的限制酶切图谱，并通过印迹杂交法确定了5.8S、19S和28S rRNA基因在其上的定位。在长形裸藻和纤细裸藻的质粒rDNA中发现了三个基因间隔区，其中两个是位于5.8S RNA基因两侧的基因间隔转录间隔区，第三个区域似乎是一个非转录间隔区。通过PCR确定了纤细裸藻的9个引物在长形裸藻19S rRNA基因上的定位；其与纤细裸藻相似。利用扩增得到的长形裸藻19S rRNA基因（2300 bp），我们测定了其3'-区域的序列，该序列与纤细裸藻的相同区域显示出87%的同源性。利用含有长形裸藻rDNA的S3-H1片段的质粒pA1 S3-H1，测定了28S rRNA基因3'-区域的序列。该序列包括与纤细裸藻Z相应区域同源的区域：12/13内部间隔区的6个核苷酸、完整的13/14内部间隔区（86 bp）、第13和14个28S rRNA组分的基因（56和86 bp），与纤细裸藻Z的同源性约为90%，以及非转录间隔区的片段（136 bp），同源性约为70%。结果表明，长形裸藻和纤细裸藻的28S rRNA基因具有相似的结构。我们的数据表明，这些植鞭毛虫密切相关。