Genetics: Analysis and Principles 5th Edition by Robert Brooker

Exercise 15

Southern blotting can be used to detect the presence of repetitive sequences, such as transposable elements, that are present in multiple copies within the chromosomal DNA of an organism. (Note: Transposable elements are described in Chapter 19.) In the Southern blot shown here, chromosomal DNA was isolated from three different strains of baker's yeast, digested with a restriction enzyme, run on a gel, blotted, and then labeled with a probe that is complementary to a transposable element called the Ty element.
a.
Explain, in a general way, why the banding patterns are not the same in lanes 1, 2, and 3.