Figure 4.—

Flies with reduced RpL38 dosage show patterning defects and a severe Minute phenotype. (A) RpL38^NC21/+ wings have no obvious defects (compare with Figure 6A). (B–D) Wings that are trans-heterozygous for RpL38^NC21 and a second RpL38 mutation have extra venation and notches in the wing margin. The images shown are typical of each genotype. (E and F) High-magnification images of part of the region bounded by vein IV, vein V, the posterior cross-vein, and the wing margin, oriented as in A–D. (E) Wing hairs from a wild-type wing point toward the distal edge of the wing margin to form an organized pattern. (F) Wing hair polarity in wings trans-heterozygous for RpL38 mutations is often disorganized. A severe example is shown here. (G–J) Notal cuticle preparations from adult flies. (G) RpL38^NC21/+ nota show a very weak Minute bristle phenotype. Compare to Figure 1A. (H) RpL38¹/+ nota show a strong Minute bristle phenotype, stronger than RpL38^2b1/+ or RpL38^2b2/+. Compare with Figure 1B. (I) RpL38^NC21/RpL38^2b2 flies have a stronger Minute phenotype than either heterozygote. Compare to G and Figure 1B. (J) RpL38^NC21/RpL38¹ flies have a very strong phenotype that is stronger than either heterozygote. Compare to G and H. Notal bristles are frequently absent, either because they are not formed or because they are fragile and break off easily. Flies were reared at 18° in this experiment to increase the number of trans-heterozygous escapers.