Wnt-4 expression induces a pregnancy-like growth pattern in reconstituted mammary glands in virgin mice.
Expression of Wnt-4, a member of the Wnt gene family, is induced during early pregnancy in the mouse mammary gland. To investigate the function of Wnt-4, we used a recombinant retrovirus to constitutively express the gene in transplanted mammary epithelium grown in virgin animals. In fully grown glands, Wnt-4 expression resulted in ducts that were more highly branched than normal and caused some premature alveolar development. These changes resembled those seen during pregnancy, suggesting that endogenous Wnt-4 expression may regulate epithelial branching in early pregnancy. The modified growth pattern induced by Wnt-4 expression was similar to that induced by Wnt-1, one of the members of the Wnt gene family activated by mouse mammary tumour virus. As Wnt-1 is not normally expressed in the mammary gland, it may exert its effect on the mammary gland by activating a developmental pathway normally regulated by Wnt-4.
Bradbury
J M
JM
Department of Pathology, University of Cambridge, United Kingdom.
Edwards
P A
PA
Niemeyer
C C
CC
Dale
T C
TC
D000818:Animals; D001483:Base Sequence; D017690:Cell Transplantation; D017931:DNA Primers / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D004847:Epithelial Cells; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008321:Mammary Glands, Animal / Q000166:cytology / Q000254:growth & development* / Q000637:transplantation; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011233:Precipitin Tests; D011247:Pregnancy; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000302:isolation & purification; D011995:Recombination, Genetic; D012190:Retroviridae / Q000235:genetics; D051153:Wnt Proteins; D060528:Wnt4 Protein
D017931:DNA Primers; D004279:DNA, Viral; D011518:Proto-Oncogene Proteins; D051153:Wnt Proteins; D060528:Wnt4 Protein; C555582:Wnt4 protein, mouse