|
Fig. 6
transparent mutant iridophores display characteristics of apoptotic cells. EM sections of wild type (A) and transparent mutant iridophores (B) in the eye of 5 dpf larvae. (A) Wild type iridophores develop stacks of iridosomes nearly completely filling the cells. Iridosomes are not contrasted and appear empty as the guanine crystals are lost during the sectioning process (arrow). (B) Iridosomes are also visible in tra mutants. In the cell shown, only two iridosomes seem to contain guanine crystals (arrows), whereas others contain contrastable material (arrowhead), indicating that guanine deposition is not completed. Importantly and in contrast to wild type, tra mutant iridophores contain many vesicles, a sign for apoptosis. Scale bars: 0.5 mm.