RESULTS
The comet assay revealed remarkable
differences in host cell nuclei between symbiotic
and non-symbiotic larvae. After 4 d of exposure
to solar radiation, host cell nuclei of non-symbiotic
planulae produced comets with no or only a short
tail. In contrast, host nuclei of symbiotic planulae
formed comets with long tails (Figs. 1, 2). The
average comet tail length was 15-times longer for
symbiotic planula samples than for non-symbiotic
ones (Fig. 3).
Comets derived from coral cells could be
distinguished from those derived from algal
symbionts. The symbionts on the comet slide
possessed intact cell walls in most cases and
did not show a typical comet shape (Fig. 4). We
could not detect DNA damage of algal symbionts
in planulae exposed to solar radiation for 4 d using
the present comet assay method.