<i>FRG1</i> myoblasts exhibit a fusion defect that is rescued in <i>FRG1</i>/FHL1 myoblasts.

<p>Quantitative RT-PCR analysis of human FRG1 (A) and human FHL1 (B) mRNA in primary mouse myoblasts isolated from wild type mice, and two <i>FRG1</i> (1 and 2) and two <i>FRG1/FHL1</i> (1 and 2) mice. Data represent the mean +/- SEM of n = 3 independent experiments and was standardized to GAPDH and expressed relative to control wild type myoblasts. *p&lt;0.05. Representative images of primary myoblasts from wild type, <i>FRG1</i> and <i>FRG1</i>/<i>FHL1</i> mice following 48 hours (C) or 96 hours (E) differentiation. Cultures were stained with the differentiation marker MHC (green) and DAPI for detection of the fusion index; the percentage of total nuclei localized within MHC-positive myotubes after 48 hours (D) and 96 hours (F) differentiation. Data represent the mean ± SEM from n = 3 independent experiments; wild type (n = 1); <i>FRG1</i> (n = 2); <i>FRG1</i>/<i>FHL1</i> (n = 2); ns not significant, **p&lt;0.005, ***p&lt;0.0001 determined by two-tailed Students T-test. Scale bars = 100μm.