遺伝子調節:植物における古代のマイクロRNA標的配列
Sandra K Floyd1, John L Bowman
1Section of Plant Biology, University of California, Davis, California 95616, USA.
Nature
|April 2, 2004
まとめ
マイクロRNAは植物における遺伝子発現を調節する. この研究は,クラスIIIホメオドメイン-ルシンのジッパー (HD-Zip) 遺伝子ファミリーの特定のマイクロRNA調節メカニズムが,すべての陸上の植物の間で保存されていて,4億年以上前に遡ることを示しています.
科学分野:
- 植物生物学 植物生物学
- 分子遺伝学 分子遺伝学
- 進化生物学の進化生物学について
背景:
- マイクロRNA (miRNA) は,エウカリオットにおける遺伝子発現を調節する小さなRNA分子である.
- クラスIIIホメオドメイン-ルシンのジッパー (HD-Zip) 遺伝子ファミリーは,植物発達において重要な役割を果たしています.
- 以前の研究では,花咲く植物におけるHD-Zip遺伝子のmiRNA調節を示していた.
研究 の 目的:
- 異なる陸地植物の系統にわたるHD-Zip遺伝子を標的としたmiRNA調節の進化的保存を調査する.
- miRNA結合部位と分裂機構が非開花植物に保存されているかどうかを判断する.
主な方法:
- 様々な陸地植物群 (ブリオフィット,ライコポッド,フェルン,種子植物) の同類配列のバイオ情報分析.
- 保存されたマイクロRNA結合部位内のメッセンジャーRNA (mRNA) 割れ目の実験的検証.
主要な成果:
- アラビドプシスのHD-Zip遺伝子の2つの特定のmiRNAの標的配列は,すべての主要な陸上の植物系にわたって保存されています.
- ホモログなHD-Zip遺伝子のメッセンジャーRNAは,各陸地植物群の代表者における保存されたマイクロRNA結合部位で分裂する.
- 開花植物と非開花植物の両方で保存されたmiRNA媒介遺伝子調節の証拠.
結論:
- マイクロRNA媒介による遺伝子調節は,陸地植物における古代のメカニズムで,開花植物の進化を先行しています.
- 特定のマイクロRNAによってクラスIIIのHD-Zip遺伝子の調節は,植物進化の4億年以上にわたって保存されています.
- この保存された規制経路は,植物開発と進化におけるマイクロRNAの根本的な重要性を強調しています.
関連する概念動画
MicroRNAs
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...
Cis-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...
RNA 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...
MicroRNAs
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...
MicroRNAs
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...
Nucleic 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...


