Wide crossing is a useful method for transferring traits of interest from wild Triticeae species to wheat. In this study, Aegilops sharonensis was successfully hybridized to three tetraploid wheat species with crossability varying from 0.86 to 1.76 %. F1 hybrids were verified by their display of intermediate characteristics in morphology, cytology, and sodium dodecyl sulfate–polyacrylamide gel electrophoresis profiles. The exogenous x- and y-type subunits of high-molecular-weight glutenin subunits of Ae. sharonensis were expressed in F1 hybrid seeds and showed identical electrophoretic mobilities to those originally present in Ae. sharonensis. In F2 hybrids, the x-type subunit migrated faster, indicating that a decrease in molecular mass had occurred. Cloning of the open reading frames of subunit variants revealed that the x-type subunit had protein sequence variations, including single residue mutations, and insertions and deletions involving one or more repeat motifs. The two deletions causing the size reduction of the exogenous x-subunits of Ae. sharonensis in the F2 seeds were most likely the result of slip-mismatching.