哺乳动物的大型核糖体RNA基因重复大小的起源和维护
Emma Macdonald1, Annabel Whibley1,2, Paul D Waters3
1School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
Genetics
|July 24, 2024
概括
哺乳动物核糖体DNA (rDNA) 单元因扩展的基因间隔器而显著更大,这种特征可能是在共同的祖先中建立并保持的,尽管有序列进化,这表明长度约束.
科学领域:
- 基因组学就是基因组学.
- 进化生物学 进化生物学
- 分子生物学分子生物学
背景情况:
- 核糖体RNA (rRNA) 基因是由真核生物中高度保守的rDNA编码的.
- rDNA被组织成串联的重复数组,在大多数真核生物中保留了单元大小.
- 哺乳动物rDNA单元显示了显著的尺寸扩张,主要是由于基因间间隙生长.
研究的目的:
- 为了研究胚胎细胞中rDNA单元大小扩张的进化时间.
- 确定特定的基因组区域,负责增加哺乳动物的rDNA单元大小.
- 探索跨基因间隔进化的潜在限制.
主要方法:
- 利用来自不同胚胎血统的长读测序数据.
- 分析了跨物种的rDNA重复单元大小和基因间隔长度.
- 在基因间隔区域内比较序列分歧.
主要成果:
- 胚胎rDNA单元大小分为两个主要类别:"正常" (11-20 kb) 和"大" (35-45 kb).
- 大型rDNA单元是单体动物,有袋动物和eutherian哺乳动物的特征.
- 增加的基因间隔长度解释了更大的哺乳动物rDNA单元大小.
- 哺乳动物的基因间隔器表现出显著的序列变化,尽管保持了长度.
结论:
- 在早期的哺乳动物祖先中,基因间隔尺寸的大幅增加发生了.
- 这种增加的尺寸在整个哺乳动物进化过程中一直保持不变,尽管有序列分歧.
- 这表明rDNA基因间间隔区域的长度存在未知的约束.
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