Molecular evolution of ribosomal DNA in Daphnia

水蚤核糖体 DNA 的分子进化

• 批准号: 130594-2011
• 负责人: Crease, Teresa
• 金额: $ 2.91万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=475713
• 关键词: Molecular; evolution; ribosomal; DNA; Daphnia; Molecular; evolution; ribosomal; DNA; Daphnia

It has been observed that sequence similarity between copies of genes that are present many times within genomes (multigene families) is very high within species, even when divergence is very high between species. This phenomenon is known as "concerted evolution". Ribosomal DNA (rDNA) is a multigene family that is present in hundreds to thousands of copies in plants and animal cells, and encodes the RNA molecules (rRNA) that make up ribosomes: the site of cellular protein synthesis. One rDNA unit consists of 3 rRNA genes separated by "spacers". The spacers contain sequences that control the rate of rRNA production. Some regions of the rDNA unit diverge between species very slowly while others, such as the spacers, diverge very rapidly, even among closely related species. Despite this rapid divergence, the sequences still retain their function.

已经观察到，即使物种之间的差异很高，基因组（多基因家族）中多次存在的基因副本之间的序列相似性也很高。 这种现象被称为“协同进化”。 核糖体DNA（rDNA）是一个多基因家族，在植物和动物细胞中以数百至数千份中存在，并编码构成核糖体的RNA分子（RRNA）：细胞蛋白质合成的位点。 一个rDNA单元由3个由“垫片”隔开的RRNA基因组成。 这些垫片包含控制rRNA产生速率的序列。 rDNA单位的某些区域之间的某些区域在物种之间的差异非常缓慢，而其他区域（例如垫片）甚至在密切相关的物种之间也很快差异。 尽管存在这种快速差异，但序列仍然保留其功能。