Supplementary Materials Flashcards
What are the two forms of DNA?
- Plasmid DNA: produced only in bacteria
- Genomic DNA: the chromosomal DNA of a cell
What does the Cry gene confer?
Cry gene is a gene isolated from Bacillus thuringiensis that causes the expression of Bt toxin - a crystal protein that is toxic to various insects. Therefore, the presence of Cry gene in plants confers insect resistance.
What does the term “organogenesis” mean?
Formation of root & shoot from callus culture
Define the mechanisms of virus resistance in plants.
Virus-resistant plants have an overexpressed viral protein coat gene. The overproduction of virus coat proteins shuts off the virus’ protein coat genes, preventing the virus from reproducing in the host cells. Such as in the case of genetically engineered papaya which is resistant to papaya ringspot virus.
What are the advantages of plant genetic engineering over animal?
- Easy to scale up
- Low cost
- Low capital expenditures
- No animal contaminants (virus)
Name three reliable methods to achieve single cell transfection
Micro-injections, electroporation using a micropipette, phototransfection using a multi-photon laser.
What are the advantages and disadvantages of virus-mediated transfection?
Advantages: Efficient, easy to achieve sustainable transgene expression.
Disadvantages: Immunogenicity and cytotoxicity, virus package has limited space for foreign gene, may interrupt essential genes, activate oncogenes, or tumor suppressor gene.
Describe Blue White Screening. What is the vector that can be screened using this technique?
A screening technique based on the presence of lacZ gene. B-galactosidase, coded by lacZ is able to convert X-gal into a blue compound. Plasmids ligated with recombinant DNA disrupts the LacZ gene of the vector. Therefore, cells transformed with vectors containing recombinant DNA will produce white colonies (lacZ gene will be absent); cells transformed with non-recombinant plasmids (i.e. only the vector) grow into blue colonies.
Vector: pUC19
