develops from develops from transformation of epithelial bud mammary placode mammary bud UBERON:0005333 mammary gland bud produced along the length of the embryonic mammary ridge these buds represent the future locations of the mammary glands. Invagination of ectoderm at each bud leads to the development of epithelial diverticula, later maturing as lactiferous ducts UBERON:0004181 EMAPA:35536 A bulb of epithelial cells that forms from the mammary placode that develops into the mammary gland. lactiferous gland bud mammary primordium milk bud ecto-epithelium