Fig. 2

Analysis of the type of myofiber formation in teratomas obtained from Pax7+/+ and Pax7−/− ESCs. a Expression of mRNAs encoding four isoforms of skeletal myosin heavy chains: Myh3, Myh7, Myh2, and Myh4 (for each genotype n = 6 or n = 7). Expression was related to the levels observed in 13.5 d.p.c. mouse embryo (E13.5; n = 3), and normalized to mRNA encoding β-actin (Actb). b Area occupied by myofibers expressing embryonic isoform of myosin heavy chains (Myh3) (for each genotype n = 6). c Localization of embryonic (Myh3, green) myofibers; localization of nuclei (blue). d Area occupied by myofibers expressing slow isoform of myosin heavy chains (Myh7) (for each genotype n = 6). e Localization of slow twitching (Myh7, green) myofibers; localization of nuclei (blue). f Area occupied by myofibers expressing fast isoform of myosin heavy chains (Myh2a) (for each genotype n = 9). g Localization of fast twitching (Myh2a, green) myofibers; localization of nuclei (blue). h Area occupied by myofibers expressing fast isoform of myosin heavy chains (Myh2b) (for each genotype n = 6). i Localization of fast twitching (Myh2b, green) myofibers; localization of nuclei (blue). Scale bar 100 μm. White bars—values for Pax7+/+ teratomas, gray bars—values for Pax7−/− teratomas. Data characterized by non-normal distribution (a, Myh2, Myh4) was normalized. Data are presented as mean ± SD. Statistically nonsignificant data was marked as “ns”. Stars represent results of Student’s unpaired two-tailed t test: *p < 0.05; **p < 0.01