Stoll R, Hobom G, Müller H
Institut für Virologie, Justus-Liebig-Universität Giessen, Germany.
J Gen Virol. 1994 Sep;75 ( Pt 9):2261-9. doi: 10.1099/0022-1317-75-9-2261.
The three avian polyomaviruses budgerigar fledgling disease virus types 1 to 3 (BFDV-1 to -3) contain genomes of identical size, 4981 bp. With differences of up to only 15 bp between the three genomes, these viruses show distinct tropism for cultured cells of various avian species: infection of chicken embryo (CE) cells with BFDV-1 and -2 results in virus propagation, whereas BFDV-3 is not replicated; all three viruses replicate, with different efficiencies, in infected Muscovy duck cells. Transfection of CE cells with BFDV-3 DNA results in a single productive cycle. As shown by construction of hybrid virus genomes and site-directed mutagenesis, a single amino acid difference (glycine instead of valine or alanine) within the common region of the minor structural proteins VP2/VP3 is responsible for this type of abortive infection of CE cells. Further experiments indicate a defect in one of the early steps during infection, at or prior to uncoating.
三种禽多瘤病毒，即虎皮鹦鹉幼雏病病毒1型至3型（BFDV - 1至 - 3），其基因组大小相同，为4981 bp。这三种病毒的基因组之间差异最大仅为15 bp，但它们对不同禽类物种的培养细胞表现出明显的嗜性：用BFDV - 1和 - 2感染鸡胚（CE）细胞会导致病毒增殖，而BFDV - 3则不复制；这三种病毒在感染的番鸭细胞中均能以不同效率复制。用BFDV - 3 DNA转染CE细胞会导致单个生产周期。通过构建杂交病毒基因组和定点诱变表明，在次要结构蛋白VP2/VP3的共同区域内的单个氨基酸差异（甘氨酸而非缬氨酸或丙氨酸）是导致CE细胞这种流产感染类型的原因。进一步的实验表明，在感染过程中的早期步骤之一，即脱壳时或脱壳前存在缺陷。
