Figure 2.

CD34 is expressed on myogenic cells and this expression is dynamically regulated during in vivo and in vitro myogenesis. (A) CD34⁻ and CD34⁺ fractions were isolated from Myf5^LacZ animals and stained for LacZ to assess β–galactosidase activity. Quantification of LacZ⁺ cells was performed. Error bars represent ± SEM for n=3 mice. (B) Representative image of LacZ-stained CD34⁻ and CD34⁺ MPCs is shown (LacZ⁺, blue). Scale bar=16 μm. (C) Representative FACS plots showing regulated CD34 expression on MPCs following NTX damage (n=3–5 mice per time-point). An isotype antibody control was used to verify specificity. (D) qRT-PCR analysis of total CD34 expression in purified MPCs after NTX damage. Error bars represent ± SEM for n=3 independent experiments with 10–20 mice per timepoint. (E) End-point RT-PCR analysis of CD34^FL and CD34^CT isoform expression from purified MPCs. (F–Q) Analysis of CD34 localization (G, J, M, P) in Pax7⁺ cells (F, I, L, O) on WT fibers at 0, 12, 24, and 42 hours post-culture (Pax7, red; CD34, green; Hoechst, blue). Scale bar=20 μm.