Eno3 Xenograft-Applicable mouse models

Skeletal muscle relies on Eno3, ortholog of human ENO3, which encodes beta-enolase, the isoform that accumulates during myogenesis and carries most 2-phosphoglycerate to phosphoenolpyruvate conversion in fast glycolytic fibers, coupling glycogenolytic flux to ATP supply during burst contraction. Recessive ENO3 mutations cause glycogen storage disease type XIII, with exercise intolerance, myalgia and elevated creatine kinase but no fixed weakness, a presentation that reflects partial rather than absolute loss of glycolytic capacity. That disease logic favors knockin of patient missense alleles over a clean null, since residual activity produces the exertional, load-dependent phenotype, whereas a muscle-restricted conditional null with Ckmm-Cre or Myf5-Cre defines the ceiling of glycolytic dependence and consequent fiber-type remodeling. Eno1 persists in muscle and partially compensates, so quantify isoform ratios before attributing any phenotype to beta-enolase. Match allele to endpoint, whether treadmill and grip performance, phosphorus 31 magnetic resonance spectroscopy of phosphocreatine recovery, or single-fiber metabolic profiling.

Orthotopic and subcutaneous routes both benefit from consistent Eno3 genetics across cages.