SPAG9 and myotonic dystrophy type 1: To more generally test the possible incidence of DM1 like splice errors in Mbnl3ΔE2 hearts, we analyzed splice events in Pdlim3/Alp, Trim55/Murf2, Mapt/Tau, Pdlim5, Sorbs1, Sorbs2, Fhod1, Spag9, Mbnl2, Myom1, Clta, Stx2, Csda, Sirt2, Atp2a1 and Atp11a RNAs, which show the aberrant retention of embryonic splice isoforms in adult Mbnl1ΔE2/ΔE2 hearts25, in 11 month old Mbnl3+/+ and Mbnl3ΔE2 hearts and from E18 Mbnl3+/+ hearts.