Ch. 21 Flashcards
Genetic Engineering- Animal Models (in vivo)
transgenic models, knockout/knockin models, reporter models, disease models
Genetic Engineering- Cell Models (ex vivo, in vitro)
gene overexpression, gene knockdown, gene knockout, mutagenesis assay
Genetic Engineering- Cell-Free (in vitro)
recombinant proteins, in vitro transcription/translation, mutagenesis
What is recombinant DNA technology
adds genes from one type of organism to the genome of another; “gene cloning”
How to manufacture recombinant DNA molecules?
- restriction enzymes
- cloning vectors
- recipient cells
selected dna- vectors- cells
How do restriction enzymes work?
cut DNA of infecting viruses at sites that are palindromic (read the same forward and backwards), protect host cell to generate single-stranded extensions called “sticky ends” (complementary to each other)
What is the most common cloning vector?
Plasmids; tool that expresses certain genes
What are transgenic organisms?
animals used to express recombinant genes in their body fluid (mimics humans)
What are the limitations of using transgenic animals?
No control over where a transgene was inserted, how many copies were inserted
Different levels of gene expression may be needed for phenotype expression in humans and model
Animal models may not mimic human condition exactly due to differences in development/symptoms
What is “knock down” in genetic expression?
to diminish expression of specific genes
What is “knock out” in genetic expression?
to silence expression of specific genes
What do gene silencing techniques do?
block synthesis of/degrade mRNA
What do gene editing techniques do?
create double-stranded breaks in DNA double helix, enable insertion of DNA sequence or remove sequence
What are RNA Hairpins?
Double stranded RNA that can fold into short regions where base sequence is completely complementary
How does RNA interference work?
- Dicer cuts double-stranded RNAs (21-24 base long siRNAs)
- Double-stranded RNAs separate and bind RISC and target mRNA
- Target mRNA is cut
