Figure 3.

Sequences of the 250 bp PCR MMTV-like env gene product amplified from the DNA of primary breast cancer tissue of mother and daughter and metastatic breast tumor tissue in lymph node of father compared with the sequences in this region of the env gene of GR, C3H and BR6 strains of MMTV. The numbers 1, 2 and 3 indicate the three locations where the BR6 strain differs from the GR and C3H strains in this region of the MMTV env gene [17,18,19]. The A and ↓ indicate the location at which the identical single base change described in the text occurs. The numbers 7656 and 7905 indicate the location of the MMTV 250 bp env gene sequence within the MMTV genome [17]. Clones are designated as M (mother), D (daughter), and F (father) followed by a number (1–4) denoting the order in which they were cloned. - denotes the same nucleotide.