Expression pattern of the BmOR-1 gene. (a) Tissue- and sex-specific expression of BmOR-1, BmOR-2, and B. mori actin genes (24), a positive control. RT-PCR products by using RNA isolated from various tissues of male and female moths, as indicated, were separated by electrophoresis. (b) Developmental analysis of BmOR-1 and PBP expression in the male antennae, with the B. mori actin gene as a positive control. RT-PCR products were separated by electrophoresis. A very faint band that corresponded to BmOR-1 product was detected at 4 days before eclosion. (c) Whole-mount in situ hybridization of BmOR-1 in the antennae of male (Left) and female (Right) moths. Reactive blue cells visualized by using an anti-DIG Ab were found on the side with chemosensory hairs. (d) A whole-mount in situ section of the male antenna viewed from olfactory sensilla side. (e) Whole-mount in situ labeling of a 2-μm plastic section of the male antenna. Labeled cells were found only in the antennal surface that carries olfactory sensilla. (f) Two-color fluorescent in situ hybridization of BmOR-1 (red) and PBP (green). Double-labeling was performed for a longitudinal (Left) and cross (Right) sections of the male antenna by using DIG-labeled BmOR-1 and fluorescein-labeled PBP antisense RNA. [Scale bar: 50 μm(c, d, and f), 20 μm(e).]