L6: Functional Genomes Flashcards
What are strategies to explore genes and function
CRISPR => site specific
RNAi => specific
Transposon mediated mutagenesis => non specific target
Why use a transposon approach
- elements can be mobilised or immobolised on demand
- needs few transformants to generate high number of org w/ transposed elements at varying locations
How do you make primary Ds Transposon lines
- co transformation (bombardment) of immature embyros with plasmids with Ds elements
- leading to Ac transposase initated by primary transposition
What does the two component transposon system require
- transposases
- jump
- landing
Give the an example of transgenic organisms
PAPAYA
* 1970: ringspot virus was found
* 91: developed transgenic w/ virus resistance
* 98: approved, ‘vaccinated’ with protein coat to induce SAR and make them resistant to virus
What is gene editing
- targetted alteration of DNA sequences
CRISPR
clustered regularly interspaced short palindromic repeats
History of gene editing
1996: Zinc finger nucleases
2003: used mega nucleases to edit genes
2010: Talen
2012-23: CRISPR Cas
What is the different in cas9 mechs
nucleotide deletion => mutation with DNA repair NHEJ
nucleotide addtion: mutation with DNA tweaking (HDR)
Discuss gene regulation by USDA
Deletions: the change to the plant is solely a genetic deletion of any size.
- Single base pair substitutions: the change to the plant is a single base pair substitution.
- Insertions from compatible plant relatives: the change to the plant solely introduces nucleic acid sequences from a compatible relative that could otherwise cross with the recipient organism and produce viable progeny through
traditional breeding. - Complete null segregants: offspring of a genetically engineered
plant that does not retain the change of its parent.