Figure 6.

In situ hybridization of sectioned light organs showing expression of the pax6, eya, six, and dac gene transcripts at 24 h post hatching. Red arrows indicate labeling of the crypt epithelia (antisense). Experimental conditions include light organs of juveniles aposymbiotic with no V. fischeri (‘Apo’), symbiotic with wild-type V. fischeri (‘Sym’), and symbiotic with Δlux V. fischeri (‘Δlux’) at 24 h post hatching. Newly hatched juveniles (‘Hatch’) are provided for comparison. The light organ reflector (r) and ink sac (is) are indicated in the representative pax6 sense image.