Chapter 21, Problem 12EQ

E12. When transgenic organisms are made, the transgene may integrateinto multiple sites within the genome. Furthermore, the integrationsite may influence the expression of the gene. For example, if atransgene integrates into a heterochromatic (i.e., highly condensed)region of a chromosome, the transgene may not be expressed. Forthese reasons, it is important for geneticists to analyze transgenicorganisms with regard to the number of transgene insertions and the expression levels of the transgenes. Chapter $20$ describes threemethods (Southern blotting, Northern blotting, and Western blotting) that can be used to detect genes and gene products. Which of these techniques would you use to determine the number oftransgenes in a transgenic plant or animal? Why is it importantto know the number of transgenes? (Hint: You may want to usea transgenic animal or plant as breeding stock to produce manymore transgenic animals or plants.) Which technique would youuse to determine the expression levels of transgenes?