UASp regulatory sequences drive expression of amino acids 1-334 of the 'atypical' Tm1 isoform ('aTm1'), mutated to carry a 12 amino acid substitutions (S20A, L21D, V22T, V45Y, V48S, A54S, L55D, Y56S, D59L, L64E, L67T, and L93Y), plus Tm1 3'UTR sequences. The protein is tagged at the N-terminal end with Emerald.