Figure 4: Each variable cassette preceded by a promoter in sDscam.
From: A large family of Dscam genes with tandemly arrayed 5′ cassettes in Chelicerata
(a) A schematic diagram of the expression of variable cassettes in M. martensii sDscamβ6. Symbols used are the same as in Fig. 1. Potential promoter elements (PPE) are shown as green circles. (b) Analysis of sDscam variable cassette promoter in the reporter assays. A portion of the sequence immediately preceding a given variable cassette was cloned into a luciferase reporter construct and subsequently transfected into Drosophila S2 cells. The luciferase vector containing the Drosophila Dscam2 promoter or intronic sequence of sDscamβ6 served as positive and negative controls, respectively. Schematic diagrams of mutants with the indicated sizes are depicted on the left. The deleted PPEs are shown as dashed circles. Data are expressed as a percentage of the mean±s.d. from three independent experiments. *P<0.05, **P<0.01 and ***P<0.001 (Student’s t-test, two-tailed); NS, not significant.
