FIG. 9.

Characterization of DTRAF2-null mutant. (A) Molecular characteristics of DTRAF2^ex1 mutant. The upper panel shows genomic structures of original EP(X)1516 and its derivative, the DTRAF2^ex1 mutant. The deleted region in DTRAF2^ex1 is displayed as a gap. In the lower panel, RT-PCR results showed that DTRAF2^ex1 lacks DTRAF2 transcription. (B) Impaired immune responses in DTRAF2^ex1 mutant. Wild type (WT, w¹¹¹⁸), DTRAF1^ex1 mutant (DTRAF1^ex1/DTRAF1^ex1), and DTRAF2^ex1 mutant (DTRAF2^ex1/DTRAF2^ex1) were infected with E. coli (+), and Northern blot analyses were performed to determine the induction of diptericin and drosomycin transcription. Control groups were not infected (−). 18S rRNA (18S rRNA) was used as a loading control. (C) Impaired nuclear-translocation of DIF and Relish in DTRAF2^ex1 mutants. Immunohistochemical analyses were completed with anti-DIF (upper panels) and anti-Relish antibodies (lower panels) to localize DIF and Relish in the fat bodies from uninfected (−) and E. coli-infected (+) wild-type (WT, w¹¹¹⁸) and DTRAF2^ex1 (DTRAF2^ex1/DTRAF2^ex1) larvae.