Expression of the paired box domain Pax7 protein in myogenic cells isolated from the porcine semitendinosus muscle after birth.
The paired box domain gene Pax7 plays a pivotal role in satellite cell physiology and may represent one of the candidate genes influencing the dynamic stages of early post-natal growth observed in pig. Quiescent satellite cells express Pax7 and, when activated, they co-express the myogenic bHLH protein MyoD. The aims of this study were to investigate, by immunohistochemistry, the putative differential expression of Pax7 and to ascertain the amount of activated satellite cells (Pax7(+)/MyoD(+)) in myogenic cells isolated at different post-natal time points and in adults. Our results indicate that Pax7(+) cells represent between 10 and 15% of the whole myogenic cell population found at birth indicating that these cells provide a modest contribution to the development of new fibres. The number of activated satellite cells (Pax7(+)/MyoD(+)) was scarce after birth but it was higher respect to adults. An interesting result was that at 1 month after birth the number of Pax7(+) cells had increased within the pool of myogenic cells with respect to myogenic cells extracted at birth. We speculate that Pax7 might be one of the molecules involved in controlling the proliferation/differentiation ratio in the pool of satellite cells present in post-natal porcine skeletal muscles.
Patruno
M
M
Department of Experimental Veterinary Sciences, Istituto Interuniversitario di Miologia, University of Padua, Viale dell'Università 16, 35020 Legnaro, Padova, Italy. marco.pat@unipd.it
Caliaro
F
F
Martinello
T
T
Mascarello
F
F
D000818:Animals; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D007150:Immunohistochemistry; D018482:Muscle, Skeletal / Q000254:growth & development / Q000378:metabolism*; D051763:PAX7 Transcription Factor / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology / Q000378:metabolism*; D034421:Sus scrofa / Q000254:growth & development* / Q000378:metabolism
D051763:PAX7 Transcription Factor