Fig. 5

CgNOS (a, c, e-g) and CgNR1 (b, d) expression localisation in competent Pacific oyster larvae and spat by in-situ hybridisation using digoxigenin labelled riboprobes (orange staining) with fluorescent signals visualised using a triple-band DAPI-FITC-Texas Red excitation filter. Frontal serial sections of foot area of the same larva 6 hpe to EPI with (a) CgNOS and (b) CgNR1, both with subsequent H&E staining of sections. Frontal sections of larvae (c) untreated with CgNOS and subsequent H&E staining of section, and (d) 6 hpe of EPI with CgNR1 and H&E staining of consecutive section. Transverse section with CgNOS probe of competent larvae (e) untreated and (f) 6 hpe EPI treatment. (g) Sagittal section whole spat and H&E staining of consecutive section. White arrows and arrow heads: signal for successful probe binding. aam: anterior adductor muscle; ci: cilia of the velum; e: oesophagus; f: foot; fg C: foot glands C; fg D: foot glands D; g: gills; gr: gill rudiments; m: mantle; mo: mouth; pam: posterior adductor muscle; pg: pedal ganglia; r. f: remnants foot; r. fg C: remnants foot glands C; vm: vellum membrane; *: Fast red dye unspecific binding mostly in remains of periostracum. Scale bar: 50 μm