A, Transverse section from PwMhc2 late stage pupa (expressing IFI wild-type isoform). B, Transverse section from IFI-9b late stage pupa. Myofibril structure for IFI-9b pupa is similar to PwMhc2 pupa, with normal hexagonal packing of thick and thin filaments. C, Transverse section from PwMhc2 one-week-old adult. D, Transverse section from IFI-9b one-week-old adult. Myofibril structures are similar in one-week-old adults. E, Longitudinal section from PwMhc2 one-week-old adult. F, Longitudinal section from IFI-9b one-week-old-adult. Sarcomere structures are similar to PwMhc2. z, Z-line; m, M-line. Scale bars, 0.5 µm.