Table 1.

Severe loss of muscle satellite cells during postnatal development

	EM	CD34	Pax7-LacZ
Pax7(−/−), P60	0.57% (1045)	No specific CD34 staining of satellite cells	0.25% (2047)
Pax7(+/−), P60	3.5% (922)	2.44% (4024)	2.05% (4181)
Pax7(−/−), P11	3.25% (677)	2.0% (1169)	6.8% (1775)
Pax7(+/−), P11	8.25% (449)	10.5% (1957)	4.45% (2067)
The number of satellite cells was estimated at P11 and P60 using either electron microscopy counting (EM), CD34 antibody staining or Pax7-lacZ staining. The number of Pax7-lacZ-positive cells in Pax7(+/−) is probably under-rated since a single Pax7-lacZ allele yields a comparatively low β-Gal activity. Numbers in parentheses indicate counted nuclei (myonuclei+satellite cells nuclei=100%).