130 likes | 347 Views
Dicer-Like. A RNA Helicase Gene Involved in Gene Silencing. UCSF. Max Bachour Jessica Chen Chris McQuilkin. A RNA Helicase Gene Involved in Gene Silencing. RNA helicase is an enzyme that unwinds RNA and modifies its structure
E N D
Dicer-Like A RNA Helicase Gene Involved in Gene Silencing UCSF Max Bachour Jessica Chen Chris McQuilkin
ARNA HelicaseGene Involved in Gene Silencing • RNA helicase is an enzyme that unwinds RNA and modifies its structure • Involved in transcription, splicing, translation, and gene silencing
A RNA Helicase Gene Involved inGene Silencing How does Dicer-Like Help with Gene Silencing?
RNAinterference • Dicer and Dicer-Like (DCL) enzymes are involved in RNA interference (RNAi) • Nontranslated RNA fragments bind to mRNA and prevent translation into a protein
Evolutionary Origins • A defense system for eukaryotes against double stranded viruses and transposons
What is Dicer’s role in RNAi? • Activated by exogenous double-stranded (ds) RNA • miRNA (micro RNA) -small, non-coding regions of double-stranded (ds) RNA 21-22 nucleotides
What is Dicer’s role in RNAi? • siRNA (small interfering RNA) non-coding regions of dsRNA 20-25 nucleotides in length
What Happened When the Dicer-Like Gene Was Knocked-out? Seed from a Wild Type Plant
Dicer-Like Mutants Cone Shaped Suspensor Cone Shaped Suspensor
How did the Dicer Knock-out Result in the Cone Shape? • Knocking-out the dicer gene keeps RNAi from forming • This keeps certain genes in the seed from being inhibited. • The lack of inhibition caused the cells in the embryo to multiply irregularly
Why did we knock-out dicer? • Provided a positive control to compare to our T-DNA knock-out line • Made sure that negative results weren’t due to technical failure • Our main goal is to discover the function genes in arabidopsis.