Troponin T is the tropomyosin-binding subunit of troponin, the thin filament regulatory complex which confers calcium-sensitivity to striated muscle actomyosin ATPase activity. Isoform 3 is expressed in the hypoderm. Isoform 8 is expressed in the dorsal vessel. Isoform 6 is expressed in adult TDT muscle and isoform 9 in adult IFM, flight and jump muscles. Isoform 2 is expressed only in larvae. Some glutamate residues are polyglycylated by TTLL3B. This modification occurs exclusively on glutamate residues and results in polyglycine chains on the gamma-carboxyl group. Flies exhibit 3 distinct syndromes of myofibrillar abnormalities; elimination of thin filaments except where they are bound by electron-dense material presumed to be Z-disk proteins, degeneration of muscles and reduction in the diameter of the myofibril lattice. Belongs to the troponin T family. Intron retention.