【摘要】 反转录病毒样粒子是反转录病毒样转座子ｃｏｐｉａ的表达产物。完整的ｃｏｐｉａＤＮＡ能在无ｃｏｐｉａ的细胞系中表达，并能启动外源基因表达，因而可作为基因工程载体使用。为迅速鉴定出的细胞系中ｃｏｐｉａ和确定其表达时期，本研究用电子显微镜对黑腹果蝇黑条体突变型细胞系中的反转录病毒样粒子进行了观察。反转录病毒样粒子为圆形，直径约０．０５μｍ，主要存在于稳定期细胞系的细胞核中，偶尔也能在细胞质中观察到，而在细胞分裂的指数增生期则完全观察不到。结果表明反转录病毒样粒子高效表达时期是细胞系的稳定期，这为选择外源基因的高效表达载体和受体系统以及分离表达产物提供了实验依据。更多还原

【Abstract】 Retrovirus like particles are expression products of copia , a retrovirus like transposon in Drosphila melanogaster. Intact copia DNA can express in copia free cell lines and initiate foreign gene expression, thus it could be developed into cloning vectros. In order to identify copia factors of cell lines rapidly and determine its expression stage exactly, retrovirus like particles in cell lines of D.melanogaster black string body mutant were scanned using electron microscopy. Retrovirus like particles observed are spheres having diameters of about 0 05 μm and exist mainly in nuclei of cell lines in stationary stage. Although scattered particles exist occasionally in cytoplasma, they disappear absolutely at logarithmic phase of cell multiplying. These results demonstrated that retrovirus like particles express massively at stationary stage of cell lines, which provided experimental basis for selecting high efficiency expression vector and host systems of foreign genes and isolating expression products.更多还原