FIGURE 1:

Drosophila S2 cells express three tropomyosin isoforms: Tm1A, Tm1J, and Tm2A/B. (A) Western blots show that at least two tropomyosin isoforms are present in S2 cell lysates: one 32 kDa in size and one 38 kDa in size. Three commercial antibodies were used: E-17 (goat; Santa Cruz Biotechnology), ab11190 (rabbit; Abcam), and TM311 (mouse; Sigma-Aldrich). (B) Schematic of Drosophila Tm1 and Tm2 gene structures. Predicted splice variants producing tropomyosin isoforms of 32 or 38 kDa in size (i.e., “canonical”) are displayed below and are based on FlyBase (FB2008_09, Dmel Release 5.12). Left, splice variant name. Right, amino acid length. Circled isoforms were confirmed through various methods (details in Supplemental Figure S1).