RNAi

RNA

ribonucleic acid, plays a key role in gene expression

Messenger RNA (mRNA)

A type of RNA that carries instructions from a gene to the ribosome, where proteins are synthesized

Small RNA (sRNA)

A type of RNA that is involved in the regulation of the expression of gene, including the microRNA (miRNA) and the small interfering RNA (siRNA)

MicroRNA (miRNA)

A type of small RNA (sRNA) that bind to specific mRNA molecule and either inhibit their translation or promote their degradation

Small interfering RNA (siRNA)

A type of small RNA (sRNA) that can cause the degradation of mRNA molecules that have complementary sequence to the siRNA and play a crucial role in RNA interference (RNAi) by silencing gene expression

Dicer

An enzyme that is involved in the processing of small RNA (sRNA) molecules into small interfering RNA (siRNA) and microRNA (miRNA) from longer double-stranded RNA precursors.

RNA-induced Silencing Complex (RISC)

A complex of proteins and RNA molecules that mediates degradation of target mRNA molecules and guides the RNA molecules to complementary mRNA strands, facilitating gene silencing.

Target mRNA

The mRNA molecule that is being targeted for degradation by the RISC complex

Degradation

the process by which a molecule is broken down into smaller components and eventually eliminated from the cell

RNA interference (RNAi)

a process of gene silencing at the post-transcriptional level, which involves the sequence-specific degradation of messenger RNA (mRNA) that carries instructions for making a protein

RNA interference (RNAi)

it prevents gene expression or this “interferes” with the transcription of RNA molecules that encode for proteins and as well as transcription of non-coding RNA molecules that serve various tasks by promoting the degradation of target mRNA molecules.

double-stranded RNA (dsRNA)

PRINCIPLE OF THE TECHNIQUE:

● Utilizes ____ to initiate the degradation of specific mRNA molecules.

● dsRNA is processed by the enzyme Dicer into small interfering RNA (siRNA) duplexes of 21-25 nucleotides in length.

● One strand of the siRNA duplex is incorporated into the RNA-induced silencing complex (RISC), which then targets complementary mRNA sequences, leading to their cleavage and degradation by RISC's catalytic component, Argonaute.

Dicer; small interfering RNA (siRNA) duplexes

PRINCIPLE OF THE TECHNIQUE:

● Utilizes double-stranded RNA (dsRNA) to initiate the degradation of specific mRNA molecules.

● dsRNA is processed by the enzyme ___ into _____ of 21-25 nucleotides in length.

● One strand of the siRNA duplex is incorporated into the RNA-induced silencing complex (RISC), which then targets complementary mRNA sequences, leading to their cleavage and degradation by RISC's catalytic component, Argonaute.

RNA-induced silencing complex (RISC); Argonaute

PRINCIPLE OF THE TECHNIQUE:

● Utilizes double-stranded RNA (dsRNA) to initiate the degradation of specific mRNA molecules.

● dsRNA is processed by the enzyme Dicer into small interfering RNA (siRNA) duplexes of 21-25 nucleotides in length.

● One strand of the siRNA duplex is incorporated into the ____, which then targets complementary mRNA sequences, leading to their cleavage and degradation by RISC's catalytic component, ____.

Dr. Peter Waterhouse; antisense RNA

In the late 1990s, _____ and his team investigated the genetic basis of flower color in petunias using ____ to block the expression of specific genes.

Antisense RNA

_____ was found to have a broader effect, leading to the discovery of RNAi, a process where small RNA molecules degrade mRNA molecules, silencing gene expression.

Andrew Fire; Craig Mello; Caenorhabditis elegans

____ and ____ independently discovered RNAi while studying gene regulation in the nematode ____ in 1998.

worm's cells

Fire and Mello introduced double-stranded RNA into the ____, leading to the discovery of RNA interference (RNAi), a process that targets only specific mRNA molecules, allowing for targeted regulation of gene expression. This groundbreaking discovery showed that introducing double-stranded RNA could effectively silence genes, paving the way for RNAi applications in research and biotechnology.

specific

RNAi revealed a new mechanism for regulating gene expression that was previously unknown, and it is a highly specific process that targets only _____ mRNA molecules.

Small interfering (siRNA)

Double-stranded RNA molecules that are typically 21-23 nucleotides in length

Small interfering (siRNA)

Designed to be complementary to the target mRNA molecule, causing it to be degraded by the RNA-induced silencing complex (RISC)

Small interfering (siRNA)

Can be used to knock down or silence the expression of a specific gene of interest

Small interfering (siRNA)

Can be delivered into cells via transfection, injection, or viral vectors

MicroRNA (miRNA)

Single-stranded RNA molecules that are typically 20-24 nucleotides in length

MicroRNA (miRNA)

Bind to complementary sequences on target mRNA molecules, resulting in either translational repression or mRNA degradation

MicroRNA (miRNA)

Can regulate the expression of multiple genes simultaneously

MicroRNA (miRNA)

Involved in a variety of biological processes, including development, differentiation, and disease

MicroRNA (miRNA)

Can be used as a tool to manipulate gene expression in research applications

Design and synthesize dsRNA or siRNA

Delivery of dsRNA or siRNA into cells

Processing of dsRNA by Dicer

Assembly of RISC

RISC-siRNA complex binds to target mRNA

mRNA cleavage and degradation

Enumerate the Basic Steps of RNAi

RNA interference (RNAi)

is a widely used technique in molecular biology research for gene knockdown and functional analysis

Andrew Fire

Craig Mello

Who were the scientists that discovered RNA interference in nematodes?

c

RNA interference involves...

a. Interference of RNA in the synthesis of DNA

b. DNA and RNA synthesis through reverse transcription

c. Silencing of specific mRNA through a complementary RNA

d. tRNA and DNA synthesis

c

RNA Interference is the process of ... at post-transcriptional level.

a. gene transcription

b. gene sequencing

c. gene silencing

d. gene coding

a

It is a double-stranded RNA molecule that initiates the degradation of target RNA molecules.

a. Small interfering RNA

b. tRNA

c. rRNA

d. Small hairpin RNA

c

RNAi can be used to study the function of genes in an organism by:

a. inhibiting translation of all mRNA in the cell

b. increasing the levels of miRNA in the cell

c. knocking down specific genes and observing the phenotype

d. overexpressing specific genes and observing the phenotype

b

What is the difference between siRNA and miRNA?

a. siRNA initiates cleavage of mRNA, while miRNA inhibits translation

b. siRNA targets specific genes, while miRNA targets multiple genes

c. siRNA has a hairpin configuration while miRNA is linear

d. siRNA is derived from endogenous genes while miRNA is derived from exogenous sources

d

What enzyme is used to process dsRNA to siRNA?

a. Polymerase

b. Drosha

c. Transcriptase

d. Dicer

b

What is the main mechanism by which RNAi causes gene knockdown?

a. Activation of enhancer sequences

b. Degradation of mRNA molecules

c. Translation of non-coding RNAs

d. Inhibition of transcription

a

It is a non-coding RNA produced inside the nucleus and has a hairpin structure.

a. miRNA

b. tRNA

c. siRNA

d. dsRNA

a

What does RNA Interference utilize to initiate the degradation of specific mRNA molecules?

a. siRNA

b. rRNA

c. tRNA

d. snRNA