Ea. Schmitt et Je. Dowling, COMPARISON OF TOPOGRAPHICAL PATTERNS OF GANGLION AND PHOTORECEPTOR CELL-DIFFERENTIATION IN THE RETINA OF THE ZEBRAFISH, DANIO-RERIO, Journal of comparative neurology, 371(2), 1996, pp. 222-234
Earlier studies suggested retinal differentiation in the zebrafish com
mences ventrally rather than centrally as is the case in other vertebr
ates. Here we describe the topographical spread of cell differentiatio
n for ganglion cells, double cones and rods in the zebrafish retina be
tween 36 and 72 hours postfertilization (hpf), by using immunohistoche
mical markers in retinal wholemounts. Staining for all three cell type
s commenced within the ventral retina on the nasal side of the optic n
erve and choroid fissure, at 38 hpf for ganglion cells and 50 hpf for
double cones and rods. Within 3 to 4 hours, the staining of ganglion c
ells and double cones spread in a continuous wave-like fashion into th
e nasal region of the ventral retina. After this time, the staining pa
tterns for ganglion cells and double cones progressed dorsally into th
e central and temporal retina. Finally, stained somata of ganglion cel
ls were observed within the temporal-ventral region by similar to 48 h
pf, more than 8 hours later than the first ganglion cells within the n
asal retina. The topographical spread of double cone staining was slig
htly less orderly. After staining had extended into the nasal retina b
etween 50 and 54 hpf, a small group of stained double cones often appe
ared at the temporal edge of the choroid fissure by 56 hpf, simultaneo
usly with initial staining observed dorsal and temporal to the optic n
erve. The topographical spread of rod staining in the ventral retina w
as more symmetrical. After rod staining appeared near the nasal edge o
f the choroid fissure at 50 hpf, rods accumulated within a localized p
atch nasal to the fissure. Approximately 5 hours after initial rod sta
ining, scattered rod staining appeared on the temporal side of the cho
roid fissure (similar to 55-57 hpf). Rods increased rapidly within the
ventral retina, and a dense symmetrical patch extended out from the c
horoid fissure into the nasal and temporal regions of the ventral reti
na by 70 hpf. A scattered pattern of rod staining also occurred within
the dorsal retina at this time. (C) 1996 Wiley-Liss, Inc.