Pax3 cre

All murine experiments were approved by the Purdue Animal Care and Use Committee (PACUC; protocol #1209000723). PACUC ensures that all animal programs, procedures, and facilities at Purdue University adhere to the policies, recommendations, guidelines, and regulations of the USDA and the United States Public Health Service in accordance with the Animal Welfare Act and Purdue’s Animal Welfare Assurance. Pax3-Cre [86 (link)] and ROSA-ZsGreen1 transgenic mice [87 (link)] were obtained from the Jackson Laboratory (Bar Harbor, ME, USA) and used to generate Pax3-Cre/ZsGreen1+ embryos in which all Pax3-expressing cells and their progeny are GFP+. Within the forelimb, the majority of GFP+ cells are of the skeletal muscle lineage (>90%), whereas the remainder are endothelial cells [45 (link)]. Males heterozygous for the Pax3-Cre transgene were time-mated with females homozygous for ROSA- ZsGreen1 and noon on the day a copulation plug was found was designated as embryonic day (E)0.5. E10.5-E12.5 Pax3-Cre/ZsGreen1+ embryos were harvested from dams euthanized via CO2 inhalation followed by cervical dislocation. The embryos were transferred to sterile phosphate-buffered saline (PBS) on ice prior to processing for immunohistochemistry or cell culture.

myf5-cre (stock 007893), R26R-mTmG (stock 007676), pax3-cre (stock 005549), myoD1-cre (stock 01440), adiponectin-cre (stock 010803) and IRβ (stock 006955) mice were from Jackson Laboratory. Mice were housed in the Animal Medicine facilities of the UMMS in a room set at 22°C and 45% humidity under a daily 12h light/dark cycles. All animal experiments were approved by the University of Massachusetts Medical School animal care and use committee.