Figure 2

Anticipated facioscapulohumeral muscular dystrophy-related gene 1 ( FRG1 ) expression during facioscapulohumeral muscular dystrophy (FSHD) myoblast differentiation. (a) FRG1 expression in three healthy (CN) and three FSHD muscle biopsies (FSHD) as revealed by means of a quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis relative to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression. (see Additional file 3 for primers), indicating the standard deviation of the mean. A two-tailed t test was used for statistical analysis; the asterisk indicates the statistical significant difference between FSHD1 and CN3 (the control with the highest level of FRG1 expression): a = 0.05, P = 0.023. (b) FRG1 expression during myogenic differentiation in healthy (CN) and FSHD (FSHD) samples, expressed as fold of GAPDH expression, indicating the standard deviation of the mean. A two-tailed t test was used for statistical analysis; asterisks indicate the statistical significant differences between: FSHD1 day 1/FSHD1 day 0, α = 0.05, P = 0.0031; FSHD2 day 1/FSHD2 day 0, α = 0.05, P = 0.0035; FSHD3 day 1/FSHD3 day 0, α = 0.05, P = 0.0036; FSHD4 day 1/FSHD4 day 0, α = 0.05, P = 0.0033. (c) Kinetics of FRG1 expression during myogenic differentiation in control and FSHD cell lines; the values were determined as median of FRG1 expression at each step of differentiation (days 0, 1, 4 and 8) after subtracting the median value at day 0. The standard error of the mean was indicated. A two-tailed t test was used for statistical analysis; the asterisks indicate the statistically significant differences at α = 0.05; controls, n = 3; FSHD, n = 4; CN day 1/FSHD day 1, P = 0.0001. These results were derived from at least three independent RNA extractions for each human cell line.