Genetics: Analysis and Principles 5th Edition by Robert Brooker

Exercise 25

Chapter 20 describes three blotting methods (i.e., Southern blotting, Northern blotting, and Western blotting) used to detect specific genes and gene products. Southern blotting detects DNA, Northern blotting detects RNA, and Western blotting detects proteins. Suppose that a female fruit fly is heterozygous for a maternal effect gene, which we will call gene B. The female is Bb. The normal allele, B , encodes a functional mRNA that is 550 nucleotides long. A recessive allele, b , encodes a shorter mRNA that is 375 nucleotides long. (Allele b is due to a deletion within this gene.) How could you use one or more of these techniques to show that nurse cells transfer gene products from gene B to developing oocytes You may assume that you can dissect the ovaries of fruit flies and isolate oocytes separately from nurse cells. In your answer, describe your expected results.