2022-11-21 ノースカロライナ州立大学(NCState)
研究者らは、トランスポゾンと呼ばれる利己的な遺伝子の「ヒッチハイカー」に関連するCRISPR-Casシステムに基づいて、生物のDNAを書き換える(単に編集するだけではない)分子ツールの特徴を新たに明らかにした。
研究チームは、多様なタイプI～FのCRISPR-Casシステムを調べ、トランスポゾンのカーゴに遺伝子カーゴ(最大1万文字の追加遺伝暗号)を加えて、細菌に望ましい変化をもたらすように、それらを工学的に設計した。
今回の発見は、CRISPRのツールボックスを拡張するものであり、治療薬やバイオテクノロジー、より持続可能で効率的な農業において柔軟なゲノム編集が必要とされる現在、バクテリアやその他の生物の操作に大きな影響を与える可能性がある。
<関連情報>
- https://news.ncsu.edu/2022/11/genetic-hitchhikers-directed-using-crispr/
- https://academic.oup.com/nar/advance-article/doi/10.1093/nar/gkac985/6830670?login=false
多様なタイプI-F CRISPR関連トランスポゾンの機能解析 Functional characterization of diverse type I-F CRISPR-associated transposons
Avery Roberts, Matthew A Nethery, Rodolphe Barrangou
Nucleic Acids Research Published:17 November 2022
DOI:https://doi.org/10.1093/nar/gkac985
Abstract
CRISPR-Cas systems generally provide adaptive immunity in prokaryotes through RNA-guided degradation of foreign genetic elements like bacteriophages and plasmids. Recently, however, transposon-encoded and nuclease-deficient CRISPR-Cas systems were characterized and shown to be co-opted by Tn7-like transposons for CRISPR RNA-guided DNA transposition. As a genome engineering tool, these CRISPR-Cas systems and their associated transposon proteins can be deployed for programmable, site-specific integration of sizable cargo DNA, circumventing the need for DNA cleavage and homology-directed repair involving endogenous repair machinery. Here, we selected a diverse set of type I-F3 CRISPR-associated transposon systems derived from Gammaproteobacteria, predicted all components essential for transposition activity, and deployed them for functionality testing within Escherichia coli. Our results demonstrate that these systems possess a significant range of integration efficiencies with regards to temperature, transposon size, and flexible PAM requirements. Additionally, our findings support the categorization of these systems into functional compatibility groups for efficient and orthogonal RNA-guided DNA integration. This work expands the CRISPR-based toolbox with new CRISPR RNA-guided DNA integrases that can be applied to complex and extensive genome engineering efforts.
