초록 ▼

Ⅳ. 연구개발결과
STA1이 splicing factor로 miRNA 생성에 중요한 역할을 함을 밝히고 수준 높은 논문으로 발표하였다. 또한, sta1-1 돌연변이체에 다른 돌연변이를 유도한 유전학적 이중변이체를 다수 확보하였다. 이들은 sta1-1 돌연변이가 정상화된 억제형과 sta1-1 돌연변이 결함이 심화된 악화형을 포함한다. 이들에 대한 표현형 분석 및 유전자 분리 연구를 수행하여, STA1 매개로하는 전사후 또는 후성유전학적 조절자 분리의 기반을 구축하였다. 아울러, 스트레스 조건하에서핵 내 존재하는 small RNA

Ⅳ. 연구개발결과
STA1이 splicing factor로 miRNA 생성에 중요한 역할을 함을 밝히고 수준 높은 논문으로 발표하였다. 또한, sta1-1 돌연변이체에 다른 돌연변이를 유도한 유전학적 이중변이체를 다수 확보하였다. 이들은 sta1-1 돌연변이가 정상화된 억제형과 sta1-1 돌연변이 결함이 심화된 악화형을 포함한다. 이들에 대한 표현형 분석 및 유전자 분리 연구를 수행하여, STA1 매개로하는 전사후 또는 후성유전학적 조절자 분리의 기반을 구축하였다. 아울러, 스트레스 조건하에서핵 내 존재하는 small RNA 군을 파악하였다.

Abstract ▼

The Arabidopsis STABILIZED1 (STA1) gene encodes a putative pre-mRNA processing factor homologous to the human U5 snRNP-associated 102kDa protein and the yeast pre-mRNA splicing factors PRP1p and Prp6p. Originally, the sta1-1 mutant was isolated using bioluminescent Arabidopsis harboring the stress-i

The Arabidopsis STABILIZED1 (STA1) gene encodes a putative pre-mRNA processing factor homologous to the human U5 snRNP-associated 102kDa protein and the yeast pre-mRNA splicing factors PRP1p and Prp6p. Originally, the sta1-1 mutant was isolated using bioluminescent Arabidopsis harboring the stress-inducible RD29A promoter-driven luciferase (RD29A-LUC) transgene, because sta1-1 showed higher luminescence under cold stress than the wild type. sta1-1 was defective in pre-mRNA splicing suggesting important roles of STA1 in pre-mRNA splicing.
We found that similar to other miRNA biogenesis-defective mutants, sta1-1 accumulated significantly lower levels of mature miRNAs and concurrently higher levels of pri-miRNAs than wild type. The dramatic reductions of mature miRNAs were associated with the accumulation of their target gene transcripts and developmental defects. Furthermore, sta1-1 impaired splicing of intron containing pri-miRNAs and decreased transcript levels of DCL1. These results suggest that STA1 is involved in miRNA biogenesis directly by functioning in pri-miRNA splicing and indirectly by modulating the DCL1 transcript level.
Through the genetic modifier screening, we also identified genetic modifiers that affected both mRNA splicing and miRNA accumulation. These results suggested that mRNA and miRNA processes share many common processing factors, of which include STA1 and STA1-related genetic factors.
We categorized these genetic modifies into two groups (enhancers and suppressors) based on their phenotypes - the enhnacers are the ones with more severe defects than sta1-1 and the suppressors are the ones with recovred phenotypes from the sta1-1 defects. Some modifires were characterized in depth in association with stress and developental phenotypes.
We also identified the group of small RNAs in nuclei of stress-treated plants. In addition, we established the transformation method of Brassica napus and generated one transformant with a potentially stress-tolerant gene expression.
All these information and results will be utilized for the further studies and Brassica crop trait improvement in the future.