Physiology 4640A/B Chapter Notes - Chapter 1: Myf5, Myogenin, Myocyte

• School: Western University
• Department: Physiology
• Course: Physiology 4640A/B
• Professor: Christopher Pin

Document Summary

Nfix regulates fetal-specific transcription in developing skeletal muscle. Key pieces of information: the tf nuclear factor ix (nfix) is robustly expressed in the fetus but absent in the embryo, nuclear factor one (nfi) proteins act as transcriptional activators and/or repressors of cellular and viral genes. In amniotes, the nfi gene family consists of four closely related genes, named nfia, Nfib, nfic, and nfix: nf1-binding sites are present on the myogenin promoter and nfi can form a complex with myogenin, thus increasing its affinity for a # of muscle-specific genes. Hypothesis: nfix causes a switch from embryonic to fetal muscle gene expression. Methodology: lof: isolate fetal myoblasts from myf5gfp-p/+ nfix1-/- mice or knock down nfix in wt myf5gfp-p/+ fetal myoblasts examine gene expression & fusion. Why myf gfp-p/+ mice: myf5gfp-p/+ mice have their myf5 mrf tagged with gfp for analysis by immunofluorescence of muscle differentiation. Answer: the selective inhibition of nfix dramatically impairs fetal myoblast differentiation & fusion.