Eye phenotypes and structure-function analysis of <i>bel</i>.

<p>(A) Wild-type eyes show regularly structured ommatidia with interommatidial bristles. (B) The <i>sev-wg</i> transgene perturbs eye development and causes a small, rough eye phenotype. (C-E) Different <i>bel</i> alleles can suppress this phenotype: alleles (C) 3R.382.1 and (D) 3R.596.4 represent mis-sense mutations. (E) A P-element induced null allele and (F) RNAi knock-down of <i>bel</i> also suppress the <i>sev-wg</i> phenotype. (G) In a wild-type (without <i>sev-wg</i>) the mis-sense mutation 3R.596.4 leads to larger ommatidia and patterning defects. (H) A similar phenotype can be observed with the null allele of <i>bel</i>. (I) In a <i>sev-wg</i> suppressor screen we isolated five recessive and one dominant <i>bel</i> suppressor alleles, all mutations reside in conserved DEAD-box RNA helicase motifs or in close vicinity. (J) When Bel is compared to human DDX3X, all mutations are located in conserved regions.