The mammary gland is a complex organ, made up of various cell types that work together for mil synthesis. A previous study had established a clonal cell line from primary bovine mammary alveolar cells (MAC-T) for the study of bovine milk production and synthesis. In this study, we transplanted MAC-T bovine alveolar cell line to BALB/C nude mice for regeneration of bovine mammary gland alveolar ducts. The MAC-T cells were suspended with matrigel and injected into the dorsal tissue of 8 weeks old male BALB/C nude mice. After 6 weeks, the injected cells were showed typical morphology of the tubuloalveolar female glands by histological analysis. It was made the branching ducts that were surrounded by smooth muscle with small alveoli budding off the ducts. In addition, the epithelial markers CK14 and CK18 were expressed within the duct-like structure. Prolactin was detected in the duct interior in these CK14 and CK18 positive cells but not in the non-transplanted MAC-T cells. These results showed that duct-like tissue had been successfully formed after 6 weeks of transplantation of the CK14 and CK18 positive MAC-T cells into mice dorsal tissue. This mouse model will be a useful tool for further research on the bovine mammary gland.

• Woo Tae Ha(Department of Stem Cell and Regenerative Biology, College of Animal Biotechnology, Konkuk University, Seoul 143-701, Korea)
• Hyun Jung Park(Department of Stem Cell and Regenerative Biology, College of Animal Biotechnology, Konkuk University, Seoul 143-701, Korea)
• Won Young Lee(Department of Food Bioscience, College of Biomedical & Health Science, Konkuk University, Chung-ju 380-701, Korea)
• Hyuk Song(Department of Stem Cell and Regenerative Biology, College of Animal Biotechnology, Konkuk University, Seoul 143-701, Korea)