A distinct profile of myogenic regulatory factor detection within Pax7.

Day, Kenneth; Paterson, Bruce; Yablonka-Reuveni, Zipora

Satellite cells are skeletal muscle stem cells that provide myogenic progeny for myofiber growth and repair. Temporal expression of muscle regulatory factors (MRFs) and the paired box transcription factor Pax7 defines characteristic phases of proliferation (Pax7/MyoD/myogenin) and differentiation (Pax7/MyoD/myogenin) during myogenesis of satellite cells. Here, using bromodeoxyuridine (BrdU) labeling and triple immunodetection, we analyzed expression patterns of Pax7 and the MRFs MyoD, Myf5, or myogenin within S phase myoblasts prepared from posthatch chicken muscle. Essentially, all BrdU incorporation was restricted to Pax7 cells, of which the majority also expressed MyoD. The presence of a minor BrdU/Pax7/myogenin population in proliferation stage cultures suggests that myogenin up-regulation is alone insufficient for terminal differentiation. Myf5 was detected strictly within Pax7 cells and decreased during S phase while MyoD presence persisted in cycling cells. This study provides novel data in support of a unique role for Myf5 during posthatch myogenesis. Developmental Dynamics 238:1001-1009, 2009. © 2009 Wiley-Liss, Inc.

Developmental Dynamics, 2009, Vol 238, Issue 4, p1001

1058-8388

Academic Journal

10.1002/dvdy.21903