The character of abnormalities found in eye development of quail embruos exposed under space flight conditions
Abstract
The avian embryonic eye is used as a model system for studies on the environmental effects on central nervous system development. Here we present results of qualitative investigation of the eye development in quail embryos incubated in micro-"g" environment. In this study we used eyes of Japanese quail (Coturnix coturnix Japonica) embryos "flown" onboard biosatellite Kosmos-1129 and on Mir station within the framework of Mir-NASA Program. Eyes obtained from embryos ranging in age from 3-12 days (E3-E12) were prepared histologically and compared with those of the synchronous and laboratory gound controls. Ther most careful consideration was given to finding and analysis of eye developmental abnormalities. Then they were compared with those already described by experimental teratology for birds and mammals. At the stage of the "eye cup" (E3) we found the case of invalid formation of the inner retina. The latter was represented by disorganized neuroblasts occupying whole posterior chamber of the eye. On the 7th day of quail eye development, at the period of cellular growth activation some cases of small eyes with many folds of overgrowing neural and pigmented retinal layers were detected. In retinal folds of these eyes the normal layering was disturbed as well as the formation of aqueous body and pecten oculi. At this time point the changes were also found in the anterior part of the eye. The peculiarities came out of the bigger width of the cornea and separation of its layers, but were found in synchronous control as well. Few embryos of E10 had also eyes with the abnormities described for E7 but this time they were more vivid because of the completion of eye tissue differentiation. At the stage E12 we found the case evaluated as microphthalmia attending by overgrowth of anterior pigmented tissues - iris and ciliary body attached with the cornea. Most, but not all, of abnormalities we found in eye morphogeneses belonged to the birds "flown" aboard Kosmos- 1129 and were likely induced by specific conditions of that flight. All sorts of disturbances we observed in eye development were similar with dom inated types found in birds and mammals on ground and could be induced by factors we intend to discuss in our report.
- Publication:
-
34th COSPAR Scientific Assembly
- Pub Date:
- 2002
- Bibcode:
- 2002cosp...34E1376G