Parity-induced mammary epithelial cells are multipotent and express cell surface markers associated with stem cells

Laurice A. Matulka, Aleata A. Triplett, Kay Uwe Wagner

Research output: Contribution to journalArticlepeer-review

86 Scopus citations


Parity-induced mammary epithelial cells (PI-MECs) are defined as a pregnancy hormone-responsive cell population that activates the promoter of late milk protein genes during the second half of pregnancy and lactation. However, unlike their terminally differentiated counterparts, these cells do not undergo programmed cell death during post-lactational remodeling of the gland. We previously demonstrated that upon transplantation into an epithelial-free mammary fat pad, PI-MECs exhibited two important features of multipotent mammary epithelial progenitors: a) self-renewal, and b) contribution to ductal and alveolar morphogenesis. In this new report, we introduce a new method to viably label PI-MECs. Using this methodology, we analyzed the requirement of ovarian hormones for the maintenance of this epithelial subtype in the involuted mammary gland. Furthermore, we examined the expression of putative stem cell markers and found that a portion of GFP-labeled PI-MECs were part of the CD24+/CD49fhigh mammary epithelial subtype, which has recently been suggested to contain multipotent stem cells. Subsequently, we demonstrated that isolated PI-MECs were able to form mammospheres in culture, and upon transplantation, these purified epithelial cells were capable of establishing a fully functional mammary gland. These observations suggest that PI-MECs contain multipotent progenitors that are able to self renew and generate diverse epithelial lineages present in the murine mammary gland.

Original languageEnglish (US)
Pages (from-to)29-44
Number of pages16
JournalDevelopmental Biology
Issue number1
StatePublished - Mar 1 2007


  • CD24
  • CD49f
  • Cre recombinase
  • Differentiation
  • Mammary gland
  • Ovariectomy
  • PI-MECs
  • Pregnancy
  • Sca-1
  • Side population
  • Stem cells

ASJC Scopus subject areas

  • Molecular Biology
  • Developmental Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Parity-induced mammary epithelial cells are multipotent and express cell surface markers associated with stem cells'. Together they form a unique fingerprint.

Cite this