| Namespace | MPheno.ontology | Obsolete | false |
| description | any anomaly in the process by which the mammary gland cord forms by elongation of the mammary bud; in female mouse embryos, the cord is formed between E15.5 and E16.5, once the elongating bud breaks through the primary mammary mesenchyme and reaches the fat pad precursor, and remains connected to the epidermis; by E16.5 a lumen develops within the sprout resulting in a primary duct opening to the exterior, and the nipple forms by differentiation of the overlying epidermis in response to signals from specialized mammary mesenchyme; in male mouse embryos, the activation of androgen receptors causes the mammary buds to separate from the epithelium between E14.5 and E15.5 and subsequently degenerate |
