bk1 << fln << bk2
Homozygous lethal. Heterozygotes have a significantly reduced flight index compared to control flies. The wingbeat frequency tends to be reduced compared to control flies, but the difference is not significant. There is a high variability in flight performance between individuals, and a wider range of wingbeat frequencies is seen in heterozygotes than in control flies. The myofibrillar structure of the indirect flight muscle (IFM) appears normal in heterozygous pupae. Heterozygous adults show defects in the lattice structure of the IFM myofibrils. The defects are most pronounced in the peripheral region of the myofibrils. The IFM fibres show altered mechanics when studied in vitro.