Figure 4.

Sequence homology of the highly variable COOH-terminal region of the MMTV sag gene of MMTV proviruses Mtv-1 [22,23] and Mtv-8 [20,21] to the amplified highly variable MMTV sag sequences cloned from the primary breast tumor tissue of the mother and daughter and metastatic breast tumor tissue in lymph node of the father. Clones are named as M (mother), D (daughter), and F (father) followed by a dash and the letter s for sag and numbers (1–4) identifying the order in which they were cloned. - denotes the same nucleotide.