Development of the mammary gland requires the coordinated action of proteolytic enzymes during two phases of remodelling. Firstly, new ducts and side-branches thereof need to be established during pregnancy to generate an extensive ductal tree allowing the secretion and transport of milk. A second wave of remodelling occurs during mammary involution after weaning. We have analysed the role of the cell surface protease aminopeptidase N (Anpep, APN, CD13) during these processes using Anpep deficient and Anpep over-expressing mice. We find that APN deficiency significantly delays mammary gland morphogenesis during gestation. The defect is characterised by a reduction in alveolar buds and duct branching at mid-pregnancy. Conversely over-expression of Anpep leads to accelerated ductal development. This indicates that Anpep plays a critical role in the proteolytic remodelling of mammary tissue during adult mammary development.
- mammary gland
- gene locus
- homologous recombination
Kolb, A. F., Sorrell, D., Lassnig, C., Lillico, S., Carlisle, A., Neil, C., Robinson, C., Müller, M., & Whitelaw, C. B. A. (2013). Mammary gland development is delayed in mice deficient for aminopeptidase N. Transgenic Research, 22(2), 425-434. https://doi.org/10.1007/s11248-012-9654-7