The mammary is a highly plastic organ that undergoes epithelial remodeling several times over the course of a mammal’s lifetime. Physiological development of the mammary is well established in literature, but the role tight junctions play in shaping the mammary gland is less understood. Development of epithelial tissues depends, in part, on the adherence of cells to maintain tissue integrity while remodeling. Claudin 7, a tight junction protein expressed in the developing epithelia, exhibits a strong presence in mammary epithelia. In this thesis we explore potential roles of claudin 7 in epithelial remodeling. We used a Cre/flox system to design an in vivo mammary-specific Cldn7 knockout. We validated our mouse line genotype using PCR genotyping. We used carmine alum staining, hematoxylin and eosin staining, and immunofluorescent staining to visualize wild type and Cldn7 Cre/flox mammary glands. This thesis furthers the knowledge of mammary gland morphogenesis by providing a foundation for a new approach to mammary remodeling in vivo.