Lobuloalveolar Differentiation and Tumorigenesis: Two Separate Activities of Mouse Mammary Tumor Virus

摘要: The morphological growth of the mammary glandular tree from 3 to 18 months age has been quantified in three groups genetically identical virgin female mice: BALB/c mice free milk-transmitted mouse tumor virus (MMTV) infection and BALB/cfC3H BALB/cfRIII carrying MMTV C3H or RIII origin, respectively. Mice were killed at 3-month intervals, their glands prepared for stereoscopic examination as whole mounts. Any cluster alveoli 0.1 mm diameter was counted measured 0.1-mm intervals. small clusters (less than equal 0.3 mm) used measure amount lobuloalveolar differentiation. larger alveoli, hyperplastic alveolar nodules, tumors frequency cell transformations. Lobuloalveolar differentiation increased significantly by both (p less 0.001) infections. induced a higher compared that 0.001). showed capability inducing nodules conclusions two different activities are carried out MMTV, namely, noduligenesis, these distinct each other.