Figure 6.

Vitamin A deficiency does not influence the mRNA levels of ninaE (the major opsin) in wild-type flies and ninaB flies. Flies were reared on normal corn medium, DWC (carotenoid-depleted white corn) medium, or DWC medium supplemented with all-trans retinal and β-carotene, respectively. Total RNA was isolated, and RT-PCR was performed as described with three different amounts of total RNA. The RT-PCR products obtained from 100, 33, and 11 ng of total RNA (indicated by the numbers 1, 2, and 3, respectively, above the figures) were separated on an agarose (1.2%) gel containing 1× 90 mM Tris/64.6 mM boric acid/2.5 mM EDTA, pH 8.3 and 0.2 μg⋅ml⁻¹ ethidium bromide. The photographs show the ninaE mRNA levels in heterozygous flies compared with ninaB^360d homozygous flies reared on standard corn medium (A), heterozygous flies compared with ninaB^P315 homozygous flies reared on standard corn medium (B), heterozygous flies compared with ninaB^P315 homozygous flies reared on DWC medium supplemented with β-carotene (C), heterozygous flies compared with ninaB^P315 homozygous flies reared on DWC medium supplemented with all-trans retinal (D), and heterozygous flies reared on standard corn medium compared with heterozygous flies reared on DWC medium (E).