Both Dr. Veltmaat and W. van Veelen contributed equally to this work.
Patterns & Phenotypes
Identification of the mammary line in mouse by Wnt10b expression
Article first published online: 8 JAN 2004
Copyright © 2004 Wiley-Liss, Inc.
Volume 229, Issue 2, pages 349–356, February 2004
How to Cite
Veltmaat, J. M., Van Veelen, W., Thiery, J. P. and Bellusci, S. (2004), Identification of the mammary line in mouse by Wnt10b expression. Dev. Dyn., 229: 349–356. doi: 10.1002/dvdy.10441
- Issue published online: 20 JAN 2004
- Article first published online: 8 JAN 2004
- Manuscript Accepted: 24 AUG 2003
- Manuscript Revised: 12 AUG 2003
- Manuscript Received: 29 MAR 2003
- Fifth Framework of the European Commission. Grant Number: QLGA-CT-2000-52130
- Dutch Cancer Fund/KWF
- French Association for Cancer Research/ARC. Grant Number: 4223
- French Ministry of Research/ACI. Grant Number: 81/2001
- California Breast Cancer Research program. Grant Number: 9PB-0082
- mouse embryo;
- mammary line;
- mammary gland development
Mammogenesis in rabbit, rat, and human begins with the formation of an elevated ectodermal ridge in the embryo. Attempts to demonstrate a morphologically or histologically equivalent mammary line in the mouse have yielded controversial results. We show here that a mammary line exists in the mouse embryo at embryonic day (E) 11.25 as a concise line of Wnt10b expression and a broader band of Wnt6 expression in the surface ectoderm, between the subaxillary and suprainguinal region of each flank. Additional streaks of Wnt10b expression in the axillary and inguinal region join the mammary line on the flank slightly later. Expression of Wnt10b and Wnt6 becomes restricted to the placodes within 1.5 days. The ectoderm of the mammary line is organized as a pseudostratified epithelium connecting the developing mammary placodes at around E11.5, whereas all other surface ectoderm is single-layered. Thus, the mammary line expressing Wnt10b defines a distinct ectodermal region that we consider the equivalent of the ectodermal ridge in, for example, rabbit. To date, the formation of the mammary line expressing Wnt10b is the earliest discernible ectodermal event in murine embryonic mammary gland development. Developmental Dynamics 229:349–356, 2004. © 2004 Wiley-Liss, Inc.