THE EFFECTS OF MESENCHYMAL CELLS ON PIGMENT EPITHELIUM OF FROG EMBRYO EYE BEFORE AND AFTER ITS DIFFERENTIATION / 解剖学报

ABSTRACT

The mesenchymal cells were carefully scraped off from the optic vesicles or eye cups at 15 to 24 stages in Rana limnocharis by a hair loop (those specimens from 21 to 24 stages were treated with trypsin in order to separate the mesenchymal cells easier) and then the optic vesicles or eye cups were transplanted into the coelom of tadpoles for 1 to 2 weeks. The transplantation of the eye cups Without scraping mesenchymal cells off at 21 to 24 stages were used as control. The results are as follows 1.The pigment epithelium of eye, which was transplanted at 15 to 20 stages, (the pigment epithelium have not differentiated at those stages) can not fully develop or only a tiny piece of pigment epithelium layer occurs. 2.The pigment epithelium of eye, which was transplanted at 21 to 24 stages, (the pigment epithelium have differentiated at those stages) can develop, but separates itself from the normal position and hangs outside the eye or curls inside the cavity of eye in a vesicular form. 3.In the intact mesenchymal cells, the pigment epithelium of eye, which was transplanted at 21 to 24 stages, can develop well and remain in normal position. These results suggest that the mesenchymal cells might have an important effect on the development and morphology of eye pigment epithelium before and after its differentiation. Before differentiation of pigment epithelium, the existence of mesenchymal cells is a necessary condition for its normal differentiation; after its differentiation, the mesenchymal cells might play a mechanical role to keep the pigment epithelium layer in normal position.