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: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=522302
• 关键词: 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.

据观察，基因组（多基因家族）中多次出现的基因拷贝之间的序列相似性在物种内非常高，即使物种之间的差异非常大。 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存在数百到数千个拷贝，并编码构成核糖体的 RNA 分子 (rRNA)：核糖体是细胞蛋白质合成的场所。 一个 rDNA 单位由 3 个由“间隔区”分隔的 rRNA 基因组成。 间隔区包含控制 rRNA 产生速率的序列。 rDNA 单元的某些区域在物种之间分化非常缓慢，而其他区域（例如间隔区）则分化非常迅速，即使在密切相关的物种之间也是如此。 尽管分歧如此之快，这些序列仍然保留了它们的功能。