MTMR12 and centronuclear myopathy: Previous data have shown that Mtm1 mice and mtm1 zebrafish morphants display an increase in PtdIns3P levels (the substrate of myotubularin) [11], [13] To investigate if mtmr12 knockdown also affects PItdIns3P levels in skeletal muscle as seen in myotubular myopathy, PtdIns3P staining was performed on control and mtmr12 morphant skeletal muscle.