Class 17 (Transgenic Organisms)

Which of the following lists in correct order the steps involved in creating a fully transgenic plant?

1. Introduce engineered Ti plasmid into bacteria. 2. Infect plant cells with transformed bacteria. 3. Grow plants from cuttings taken from infected plants. 4. Collect seeds produced by cutting-generated plants. A transgenic plant expresses the introduced genes in its own cells and produces seeds that will grow into progeny also expressing that gene. Because only some cells of the infected plant will likely express the introduced gene, it is necessary to first grow new plants from cuttings of the original plants, then allow them to cross-fertilize and collect the seeds.

Which of the following features on an engineered Ti plasmid ensures the production of a significant amount of mRNA from the introduced gene?

CaMV promoter Engineered Ti plasmids can be used to introduce new genes into plant cells without harming the plant. In order to achieve transcription of the introduced gene, it must be associated with a promoter. A highly efficient promoter such as CaMV serves to maximize expression levels.

What naturally occurring feature of the Ti plasmid makes it useful in genetic engineering of plants?

It is capable of introducing exogenous genes into plant genomes. Cells of the species Agrobacterium tumefasciens containing the Ti plasmid produce a nonlethal condition in plants called crown gall. The Ti plasmid induces cells of the infected plant to multiply in large numbers, causing the crown galls. T-DNA genes are removed from the Ti plasmid and are replaced with the gene of interest.

Your lab supervisor wants you to knockout the NOS gene in mice to see if it affects fertility. What is your supervisor asking you to do?

Replace a functional NOS with a non-functional copy