Fig. 3.

Electron microscopic analysis of α-catenin fl/fl control and α-catenin deficient mammary tissue. (A) Micrograph of mammary tissue from α-catenin fl/fl control mice at parturition. Cells were stretched along the circumference of the lumen and appeared secretory as evidenced by milk fat droplets (arrow). (B) Micrograph of mammary tissue from a α-cat fl/fl;WC mouse at parturition. Note the clustering of cells and lack of a lumen (arrow) and secretory evidence. lu, lumen; s, secretory cell; nu, nucleus.