Donovan M J, Hart N H
J Exp Zool. 1986 Mar;237(3):391-405. doi: 10.1002/jez.1402370312.
Activation of the teleost (Brachydanio) fish egg includes the exocytosis of cortical granules, the construction of a mosaic surface consisting of the unfertilized egg plasma membrane and the limiting membranes of the cortical granules, and the appearance of coated and smooth vesicles in the cytoplasm (Donovan and Hart, '82). Unfertilized and activated eggs were incubated in selected extracellular tracers to (1) determine experimentally if cortical granule exocytosis was coupled with the endocytosis of membrane during the cortical reaction, and (2) establish the intracellular pathway(s) by which internalized vesicles were processed. Unfertilized eggs incubated in dechlorinated tap water or Fish Ringer's solution containing either horseradish peroxidase (HRP; 10 mg/ml), native ferritin (12.5 mg/ml), or cationized ferritin (12.5 mg/ml) were activated as judged by cortical granule breakdown and elevation of the chorion. Cells treated with HRP and native ferritin exhibited a delay in cortical granule exocytosis when compared with water-activated eggs lacking the tracer. Each tracer was internalized through the formation of a coated vesicle from a coated pit. Since coated pits appeared to be topographically restricted to the perigranular membrane domain of the mosaic egg surface, their labeling, particularly with cationized ferritin, strongly suggested that the retrieved membrane was of cortical granule origin. Cationized ferritin and concanavalin A (Con A) coupled with either hemocyanin or ferritin labeled the surface of the unactivated egg and both domains of the mosaic egg surface. Transformation of the deep evacuated cortical granule crypt into later profiles of exocytosis was accompanied by increased Con A binding. Within activated egg cortices, HRP reaction product, native ferritin, and cationized ferritin were routinely localized in smooth vesicles, multivesicular bodies, and autophagic vacuoles. Occasionally, each tracer was found in small coated vesicles adjacent to the Golgi and within Golgi cisternae. The intracellular distribution of HRP, native ferritin, and cationized ferritin suggests that internalized membrane is primarily processed by organelles of the lysosomal compartment. A second and less significant pathway is the Golgi complex.
硬骨鱼（斑马鱼）卵的激活包括皮质颗粒的胞吐作用、由未受精卵质膜和皮质颗粒的界膜组成的镶嵌表面的构建，以及细胞质中被膜小泡和平滑小泡的出现（多诺万和哈特，1982年）。将未受精卵和激活卵置于选定的细胞外示踪剂中孵育，以（1）通过实验确定皮质颗粒胞吐作用在皮质反应过程中是否与膜的内吞作用相关联，以及（2）确定内化小泡的细胞内处理途径。将未受精卵置于脱氯自来水中或含有辣根过氧化物酶（HRP；10毫克/毫升）、天然铁蛋白（12.5毫克/毫升）或阳离子化铁蛋白（12.5毫克/毫升）的鱼类林格氏液中孵育，通过皮质颗粒破裂和绒毛膜升高判断其被激活。与不含示踪剂的水激活卵相比，用HRP和天然铁蛋白处理的细胞皮质颗粒胞吐作用出现延迟。每种示踪剂都是通过从有被小窝形成有被小泡而被内化的。由于有被小窝在地形上似乎局限于镶嵌卵表面的颗粒周围膜区域，它们的标记，特别是阳离子化铁蛋白的标记，强烈表明回收的膜起源于皮质颗粒。阳离子化铁蛋白和伴刀豆球蛋白A（Con A）与血蓝蛋白或铁蛋白偶联，标记未激活卵的表面和镶嵌卵表面的两个区域。深度排空的皮质颗粒隐窝向胞吐后期形态的转变伴随着Con A结合增加。在激活的卵皮质内，HRP反应产物、天然铁蛋白和阳离子化铁蛋白通常定位在平滑小泡、多泡体和自噬泡中。偶尔，每种示踪剂会出现在与高尔基体相邻的小有被小泡中和高尔基池内。HRP、天然铁蛋白和阳离子化铁蛋白的细胞内分布表明，内化膜主要由溶酶体区室的细胞器处理。第二条不太重要的途径是高尔基体复合体。
