Table 1.

Densities of rod and cone photoreceptors in control and RA-treated embryos, and in theoretical datasets

	Cell densities (cells/3600 μm2)
	60 hpf		75 hpf
Cell Type	Control	RA	Control	RA
Rods	9.56 ± 2.55	19.2 ± 6.75**	16.2 ± 2.68	N.D.a
Cones:
Red	70.5 ± 12.69	53.33 ± 13.42*	59.50 ± 8.23	28.40 +8.53***
Blue	45.44 ± 5.66	37.1 ± 8.30*	52.56 ± 18.56	38.33 ± 10.71*
UV	47.33 ± 6.96	40.11 ± 5.80*	N.D.	N.D
	Theoretical red cone loss (n = 5)b
	25% loss	50% loss	25% loss	50% loss
	48.4 ± 10.81**	32.40 ± 7.5***	43.20 ± 7.53**	29.40 ± 5.81***

*p < 0.05; **p < 0.01; ***p < 0.001 (Student's t-test).

N.D. = Not done.

^a Rod density was so high as to preclude accurate counting.

^b As compared to red cone density at 75 hpf.