Visual pigment and visual receptor cells in fetal and adult sheep.

摘要: The visual pigment, and the structure of cells, were investigated by spectrophotometry light electron microscopy in fetal adult sheep. rhodopsin system sheep closely resembles that cattle. absorbance maxima rhodopsin, lumirhodopsin, 7netarhodopsin I are at 498, 490, 480 nm, respectively. estimated molar coefficient wavelength maximum absorption is 40,000M~ ] • cm~\ Rhodopsin was detected from a age 85 days (term 145 days). Partial bleaching extracts eyes (95, 105, 115 days) did not demonstrate cone pigments, although cones present fair numbers about 105 days. time course formation between 140 growth curve. amount shortly before birth (140 0.6 times adult. number dimensions rod outer segments as well packing discs studied structurally related to content. A fairly good correlation found earliest stages (95 gestation age), when concentration very low few small, latest stage At content observed less than indicated segment volume, probably mainly due possibly molecules being tightly packed (INVEST OPHTHALMOL VIS Sci 23:409418, 1982.)