[Preliminary study on apoptosis of DEF cells induced by new type gosling viral enteritis virus (NGVEV) infection].

The characteristics changes of apoptosis of Duck Embryo Fibroblasts (DEF) cells induced by New type gosling viral enteritis virus, NGVEV) were observed by means of HE staining, electron microscopy and Annexin V-FITC/PI fluorescent staining. During 24-48 h post infection (pi), the difference of morphological change between infected DEF cells and the mock infected cells was invisible. At 72 h pi, the nuclear chromatin was getting condensed through HE staining; apoptotic morphological change such as abnormal shape of the nucleus, condensation of the cytoplasm and chromatin were observed under electron microscope; and the early apoptotic cells (Annexin V-FITC positive and PI negative) were detected under fluorescence microscope. At 96-120 h pi, by means of HE staining and electron microscopy, the advanced morphological change of apoptosis such as formation of different kinds of apoptotic bodies, and shrink of the DEF cells and nucleus were detected; under fluorescence microscope the different stages of the apoptotic DEF can be easily distinguished: early apoptotic cells (Annexin V-FITC postive and pi negative), advanced or late apoptotic cells (both Annexin V-FITC and PI positive), necrosis cells or dead cells (Annexin V-FITC negative and PI positive). This investigation shows that NGVEV might induce apoptosis and form characteristic apoptotic morphological changes in the DEF cells. NGVEV inducement of apoptosis may be an important mechanism of efficient dissemination of virus progeny.