Troponin T is the tropomyosin-binding subunit of troponin, the thin filament regulatory complex which confers calcium-sensitivity to striated muscle actomyosin ATPase activity.

(UniProt, P19351)

80-85% of int flies hold wings ventrolaterally, 10% hold them vertically and the remainder maintain normal wing position. In many flies mesonotum indented to variable degree and at various positions; 85% in flies raised at 29 and 45% when raised at 18. More extreme expression in y flies; partially dominant in y genotypes. Fate mapping indicates focus in presumptive thoracic musculature. Indirect flight muscle structure badly deranged, Z-bands disappear as muscles degenerate; also lose a 54k protein. int/int adults flightless and unable to jump; int/+ adults normal.

Wings held upright and mutants unable to jump or fly when homo- or hemizygous. The indirect flight muscles of the thorax are abnormal, with many mitochondria in the muscle fiber envelopes but with defective myofibrils (Hotta and Benzer, 1972; Deak, 1977); electron microscope and electrophoresis studies indicate that these muscles lack internal structure in the Z-bands and Z-band proteins (Fekete and Szidonya, 1979; Mogami et al., 1981). Although wings are held in normal position, wild-type heterozygotes of certain mutant alleles are unable to jump or fly; their muscles contain half the normal amount of Z-band proteins. Fate maps of the behavioral and morphological foci of up and up2 indicate that the gene has its site of action in the presumptive musculature of the ventral mesoderm (Hotta and Benzer, 1972; Deak, 1977). Viability and fertility of up is good. RK1.