| 摘要: |
| 根据GenBank 中已知的条斑紫菜(Porphyra yezoensis)SSU 和LSU rRNA 基因序列分别设计引物,分别以混合个体和单个个体的基因组DNA 以及cDNA 为模板进行扩增, 测序分析后推测SSU rRNA 基因中的内含子转录后加工可能仍被保留, 而在LSU rRNA 基因上游序列中没有发现内含子。长511bp的内含子位于SSU rRNA 基因序列的上游, 其插入位点为TCTGGTG-CCAGCAGCC, 内含子5′ 和3′端的核苷酸序列分别为AAC-和-ATGG。该内含子的剪接位点以及保守区P, Q, R, S 与I 型内含子是不同的。研究发现, 在同种紫菜中, 不同个体SSU 基因中内含子的有无、分布及结构特征是不同的, 说明内含子对于分类是不太适合的。但是内含子的长度以及核苷酸序列在种间又具有一定的特异性, 可以为红藻种间以及种内亲缘关系较远的亚种和不同地理群的区分和鉴定提供参考。 |
| 关键词: 条斑紫菜(Porphyra yezoensis) rRNA 基因 内含子 同质性 系统发育 |
| DOI：10.11759/hykx20130930001 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(41276134) |
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| Analysis of intron in SSU of Porphyra yezoensis |
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| Abstract: |
| Fragments were amplified using primers designed on the basis of SSU and LSU rRNA gene sequences of Porphyra yezoensis, respectively published in GenBank. Genomic DNA and cDNA of mixed or single P. yezoensis thallus were used as templates. After sequencing and analyzing these fragments, it is presumed that the intron in SSU rRNA gene is not excised in the succedent processing after transcription, and intron was not discovered in LSU rRNA gene. The intron which locates upstream in SSU rRNA gene is 511 bp. The location of intron is the TCTGGTG-CCAGCAGCC exon sequence, and the 5′-end and 3′-end of the intron are AAC- and -ATGG, respectively. The splicing site and conserved regions P, R and S of it are different from type I intron. Moreover, there are differences in characteristics such as presence, location and structural feature of introns between individuals of P. yezoensis thallus. So it is not appropriate to use introns for classification between intra-species. However, the length and nucleotide sequence of introns are specific in various species, which may provide references for discrimination of red algae between inter-species and intra-species with distant relationship or different biogeography. |
| Key words: Porphyra yezoensis ribosomal DNA introns homogeneity phylogenetic development |
