硫酸糖胺聚糖(Sulfated Glycosaminoglycans)在花背蟾蜍眼早期形态发生中的合成

SYNTHESIS OF SULFATED GLYCOSAMINOGLYCANS DURING EARLY MORPHOGENESIS OF THE EYE IN BUFO RADDEI

本文用放射自显影追踪注射入胚胎的^(35)S-硫酸盐的方法,研究了花背蟾蜍早期形态发生时眼的各部分组织和细胞外基质中的硫酸糖胺聚糖(Sulfated Glycosaminoglycans简称:硫酸GAG)的合成,并分析了其在眼形态发生中的作用。结果表明:1.在眼早期形态发生时,合成的硫酸GAG主要是硫酸软骨素。2.眼各部分组织中在即将分化时硫酸GAG合成率增高,分化开始后逐渐下降到原基形成时的水平。3.在晶状体被诱导时,在视杯和晶状体相互贴近的组织及两者间的细胞外基质中硫酸GAG的合成率明显增加,提示这是晶状体诱导的重要因素。4.角膜上皮形成时即向角膜上皮下层和细胞外基质分泌硫酸GAG;角膜上皮透明时,合成更多的硫酸角质素。

Synthesis of sulfated glycosaminoglycans (GAGs) in various parts and extracellular matrix (ECM) of the eye during early morphogenesis of Bufo raddei was studies with autoradiography following injection into embryos with 35S-sulfate, and the effect of sulfated GAGs in morphogenesis of the eye was analysed.The results show that: (1) Sulfated GAGs that has been synthesized during morphogenesis of the eye mainly are chondroitin sulfate; (2) Immediately before the onset of differentiation of the eye tissues, the rates of sulfated GAGs synthesis are increased, and once after the beginning of differentiation, the rates of sulfated GAGs synthesis are gradually lowered (or decreased) to the level as the same of primordium formation; (3) The rates of sulfated GAGs synthesis are evidently increased during the period of lens induction over the tissues adjacent to the optic cup and the lens and the ECM between them. It is indicated that this is an important factor for lens induction; (4) The corneal epihelium, once formed, has secreted sulfate GAGs to postepithelial layer and ECM, and when the corneal epithelium became transparency it syn-hesises more keratan sulfate.