Fig. 8.

Interactions between Ddx1andSirup. (A) Pictograph showing the structure of Sirup and the variable splice junction site (top – transcript expressed in control flies; bottom – transcript expressed in Ddx1^AX/AX flies). (B) RT-PCR analysis of control and null larvae and adult flies. A spliced Sirup product is only observed in Ddx1 null animals. (C) IP using anti-Ddx1 antibody demonstrating that almost all Ddx1 protein is retained in the immunoprecipitate. (D, E) Left panels – RT-PCR analysis of RNA co-immunoprecipitated with Ddx1 or IgG. Right panels – RT-PCR of cDNA generated from control flies used as a positive control for the PCR reaction. Sirup mRNA results indicate that Sirup RNA, but not Ddx1 RNA, is pulled down with Ddx1 protein. (F) RT-PCR analysis shows reduced Sirup RNA levels in Sirup knock-down adult flies. (G) Progeny generated from y¹w^*; Actin5C-Gal4/CyO; Ddx1^AX/TM3, Sb x y¹w^*; UAS-Sirup-RNAi; Ddx1^AX/TM3, Ser GFP crosses. Expected ratios of 2:1 for heterozygous to homozygous mutant Ddx1 and 1:1 for Sirup knock-down to CyO. A significant reduction in the number of Sirup knock-down flies was observed. Chi square analysis comparing observed distribution to expected distribution was used to determine significance.