Figure 5. The developmental time course and pattern of expression of BCO2, RDH12, and RETSAT are consistent with their proposed role in apocarotenoid metabolism.

(a) In situ hybridization for transcripts of each of the enzymes in the proposed biosynthetic pathway, performed on retinas from newly hatched chickens indicate enzyme expression in the photoreceptor layer of the retina (ONL). No signal was detected in the negative control (RETSAT sense probe; bottom panel). The outer nuclear (ONL), inner nuclear (INL) and ganglion cell layers (GCL) are indicated in each section. (b) The concentration (μg mg⁻¹ of protein) of dihydrogalloxanthin and galloxanthin in whole retina extracts from chicken (Gallus gallus) increase significantly over the course of development from embryonic day 16 (E16) to 21 days post-hatch (P21). (c) The transcript levels of BCO2, RETSAT, and RDH12 also increase significantly over development. Values are reported as fold-change relative to the earliest time point (E16). Three biological replicates were analyzed at each time point.

DOI: http://dx.doi.org/10.7554/eLife.15675.015