Overall, the results demonstrate that individual cells of
transgenic fish can be imaged in vivo to an unprecedented
level of resolution comparable to the stereomicroscope’s
ability to image the same tissue dissected from the eye.
Further, the method enables examination of the same retina
during trials separated by multiple days. The technique
employed endogenous and experimentally induced landmarks
in the retina, allowing us to repeatedly document the same
photoreceptors following light-induced cell ablation. Previous
work has shown that intense light exposure leads to ablation
of photoreceptors in fish [17,27,28], and can be used to study
degeneration or subsequent regeneration of cells. Intriguingly,
this methodology documented the appearance of new fluorescent
objects in the retina 7 days following ablation (Figure
4, Figure 5), and we interpreted these objects as regenerating
photoreceptor cells. The possibility that these newly
appearing photoreceptors were undetectable at earlier time
points cannot be excluded. However, it is well established
that photoreceptor ablation induces stem cell proliferation