Expressions of BMP2, BMP4, and Their Receptors during the Development of Mouse Tongue Muscle

Abstract

Objective: The development of mouse tongue muscle has been already studied extensively, but the involvement of bone morphogenetic protein (BMP) signals in thedevelopment of tongue muscle is not fully understood. Thus, the aim of the present study is to identify if BMP signals are involved in the proliferation, differentiation and maturation processes of mouse tongue muscle.
Methods: Localization of BMP2, 4, BMP receptor (BMPR) IA, IB, II, activin receptor (ActR) IA, ActRII, and ActRIIB was analyzed in mouse tongue muscle between embryonic day 11 (Ell) and the newborn stage by immunohistochemical method.
Results: All of the BMPs and their receptors studied herein were not detected at Ell. The expressions of BMP2, BMPRIB, ActRIA, ActRII and ActRIIB were first observed at E13, while those of BMP4, BMPRIA, and BMPRII were first observed at E15. The expressions of all BMP and receptor proteins were markedly high at E15, and decreased thereafter. BMP2, BMPRIA, ActRIA, and ActRII continued to be expressed until the newborn stage.
Conclusion: The expression profiles described above suggest that 1) BMP2, BMPRIB, ActRIA, ActRII, and ActRIIB play roles in differentiation; 2) all of the BMPs and receptors studied herein are involved in the initiation of maturation; 3) only BMP2, BMPRIA, ActRIA, and ActRII are involved in the whole process of maturation.