Fig. 5

Reduced skeletal muscle precursor cell proliferation in the Pax7 ^−/− TZ. a, b, d, e Longitudinal sections of P7 Pax7 ^+/− and Pax7 ^−/− esophagi were stained with either MyoD (a, b) or Myogenin (d, e) antibodies and DAPI. The TZ was analyzed. c, f Quantification of MyoD⁺ (c) and Myogenin⁺ (d) cells within the TZ, measured as a percentage of total DAPI⁺ cells in the ME. Values are means ± SD, n = 3–5. g–j, l–o Longitudinal sections of P7 Pax7 ^+/− and Pax7 ^−/− esophagi were stained with either Ki67 (g–j) or phospho-histone H3 (PH3) (l–o) and DAPI. The TZ and distal region were analyzed. k, p Quantification of Ki67⁺ (k) and PH3⁺ (p) cells within the TZ and distal region, measured as a percentage of total DAPI⁺ cells in the given region. The numbers of Ki67⁺ and PH3⁺ cells were reduced in the TZ in Pax7 ^−/− mice, but not in the distal region. Values are means ± SD, n = 4–5. q–v Longitudinal sections of P7 Pax7 ^+/− and Pax7 ^−/− esophagi were stained with MyoD and Ki67 antibodies and with DAPI. w Quantification of MyoD⁺/Ki67⁺ cells within the TZ, measured as a percentage of total DAPI⁺ cells in the TZ. Values are means ± SD, n = 4. x–cc Longitudinal sections of P7 Pax7 ^+/− and Pax7 ^−/− esophagi were stained with M-cadherin (Mcad) and Ki67 antibodies and with DAPI. dd Quantification of total Mcad⁺ and Mcad⁺/Ki67⁺ cells within the TZ, measured as a percentage of total DAPI⁺ cells in the TZ. Values are means ± SD, n = 4. Bars: 0.2 mm (a–v); 20 μm (x–cc). *P < 0.05; **P < 0.01