雏鹅新型病毒性肠炎病毒强毒在感染鸭胚体内形态发生学和宿主细胞超微病理学研究

Morphogenesis of New Gosling Type Viral Enteritis Virus and Ultrastructural Pathology of Tissues in Experimentally Infected Duck Embryo

将雏鹅新型病毒性肠炎病毒（NGVEV）强毒CH株经尿囊腔途径人工感染10日龄鸭胚，应用透射电镜和超薄切片技术研究病毒在宿主细胞内的形态发生及各组织器官的超微结构变化。结果表明：感染后不同时间剖杀及死亡鸭胚的尿囊膜、肠、心、肝、脑和肌胃组织中，均观察到60～70nm的病毒粒子。病毒粒子主要通过与细胞膜融合而进入细胞质内，然后在细胞核内进行复制和装配。最后病毒粒子通过核膜和细胞膜破裂的方式被释放。病毒侵害的主要靶细胞包括鸭胚尿囊膜上皮细胞、肠上皮细胞、肠道平滑肌细胞、成纤维细胞、肝细胞、肌胃黏膜上皮细胞和心肌细胞等，表现为细胞核内外膜间隙严重扩张，细胞质整体结构严重空化。病毒侵害的主要靶细胞器包括粗面内质网和线粒体，表现为粗面内质网扩张呈囊状；尿囊膜上皮细胞的线粒体出现固缩和异常聚集变化，而其他组织细胞的线粒体均表现为肿胀和嵴断裂、消失。本试验还发现NGVEV可诱导宿主细胞发生严重的细胞凋亡现象，表现为细胞皱缩，胞核内染色质密度增高，核固缩成一个或数个团块凝聚在核膜周边，胞质浓缩深染并形成凋亡小体。

The morphogenesis of new gosling type viral enteritis virus （NGVEV） in duck embryo and the ultrastructural changes of host cells were observed and analysed by using electron microscopic techniques. 10 days old duck embryos were infected experimentally with NGVEV. Chorioallantois,intestine, heart, liver, brain and muscular stomach were collected at different times. The investigation showed that the typical adenovirion could be found in chorioallantois, intestine, heart, liver, brain and muscular stomach at the different infection stages. The virus particles were round in shape with diameter of 60-70 nm. There are three significant morphogenetic envents of NGVEV according to our observation： entry, virion morphogenesis and release. The virion entered the cell by attaching to cytoplasmic membrane and replicated,matured in the nucleus. Finally virions released into extracellular space through broken of cytoplasmic membrane. The target cells that virus mainly attacked were the chorioallantois epithelial cells, intestinal epithelial cells, smooth muscle cells of intestine, fibrocytes, hepatocytes ,muscular stomach mucus membrane epithelial cells and cardiac muscle cells. The target organelles that virus mainly attacked were rough endoplasmic reticulum （RER） and mitochondria （Mi）. RER in the cytoplasm expanded heavily during infection. Mitochondria in the chorioallantois epithelial cells were ultracondensed and aggregated into compact clusters, but mitochondria in other cells were inflated and disaggregated after NGVEV infection. NGVEV could induce apoptosis in host cells. The morphological changes of apoptosis including the apoptotic cells shrank, chromatin condensation and margination, and the formation of apoptotic bodies.