基因调节:植物中古代的微RNA标序列
Sandra K Floyd1, John L Bowman
1Section of Plant Biology, University of California, Davis, California 95616, USA.
Nature
|April 2, 2004
概括
微RNAs调节植物中的基因表达. 这项研究表明,在所有陆地植物中保存的III类家庭主体-氨酸拉链 (HD-Zip) 基因家族中,一种特定的microRNA调节机制可以追溯到4亿多年前.
科学领域:
- 植物生物学 植物生物学
- 分子遗传学 分子遗传学
- 进化生物学是进化的生物学.
背景情况:
- 微RNAs (miRNAs) 是小型RNA分子,它们调节了真核生物中的基因表达.
- 第三类家庭 - 氨酸拉链 (HD-Zip) 基因家族在植物发育中起着至关重要的作用.
- 之前的研究表明miRNA调节了开花植物中的HD-Zip基因.
研究的目的:
- 调查miRNA调节的进化保存,针对各种陆地植物系的HD-Zip基因.
- 为了确定miRNA结合部位和分离机制是否在非开花植物中保留.
主要方法:
- 来自各种陆地植物群的同源序列的生物信息分析 (类植物,白类植物,类植物,种子植物).
- 在保存的微型RNA结合部位内对信使RNA (mRNA) 裂变的实验验证.
主要成果:
- 在Arabidopsis HD-Zip基因中,两个特定的miRNA的目标序列在所有主要的陆地植物谱系中都保留着.
- 同类HD-Zip基因的信使RNA在每个陆地植物群体的代表中被切割在保存的microRNA结合部位.
- 在开花植物和非开花植物中都存在保存的miRNA介导基因调节的证据.
结论:
- 微RNA介导的基因调节是陆地植物的一个古老的机制,早于开花植物的进化.
- 通过特定的微RNAs调节III类HD-Zip基因已经保存了超过4亿年的植物进化.
- 这种保存的调节途径凸显了微RNA在植物发育和进化中的基本重要性.
相关概念视频
01:22MicroRNAs
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends...
02:02Cis-regulatory Sequences
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...
02:23RNA Editing
RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...
01:22MicroRNAs
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends...
01:22MicroRNAs
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA...
01:25Nucleic Acid Structure
The pentose sugar in DNA is deoxyribose, while in RNA the pentose sugar is ribose. The difference between the sugars is the presence of the hydroxyl group on the ribose's second carbon and a hydrogen on the deoxyribose's second carbon. The phosphate residue attaches to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′ to 3′ phosphodiester linkage.
DNA Structure
DNA has a double-helix structure. The...
DNA Structure
DNA has a double-helix structure. The...