ON THE REPLICATION OF INCOMPLETE CHROMOSOMES OF PHAGE T4

Some small particles of phage T4 contain incomplete chromosomes measuring two thirds of the length of normal T4 chromosomes. They cannot produce progeny phage after single infection because their incomplete chromosomes lack random segments of the genetic map. We have investigated the replication of DNA following single infection with small particles. Our results indicate that approximately two thirds of the incomplete chromosomes can initiate DNA replication and apparently extend the process from a genetically fixed origin to one end of the molecule. However, few if any of the incomplete chromosomes can initiate a second round of replication. The incomplete chromosomes which do not replicate also do not attach to bacterial membranes.     

ANTIBODIES TO RIBONUCLEIC ACID IN SYSTEMIC LUPUS ERYTHEMATOSUS

Sera of 16 of 89 patients with systemic lupus erythematosus contained precipitating antibodies to RNA. These antibodies were found infrequently in patients with rheumatoid arthritis and Sj?gren's syndrome, and not at all in patients with juvenile rheumatoid arthritis, myeloma, nor in normal individuals. These studies present evidence for the presence of antibodies to double-stranded RNA (both synthetic and viral). The fact that mammalian RNA's are probably single-stranded nucleotides suggests that these anti-RNA antibodies are directed primarily to a foreign, double-stranded RNA antigen.     

抗华支睾吸虫噬菌体抗体库的构建

目的　构建抗华支睾吸虫噬菌体抗体库 ,以期筛选出抗循环抗原的抗体组合。方法　应用噬菌体表面呈现技术 ,从感染华支睾吸虫病人淋巴细胞中提取总 RNA,逆转录成 c DNA后 ,用相应引物 PCR扩增出重链 Fd和轻链基因 ,经 Xho 和 Spel、Sac 和 Xba 双酶切 ,先后克隆入噬粒载体 p Comb3,再电转化大肠杆菌 XL1- blue菌株 ,辅助噬菌体 VCSM13超感染。结果　从感染华支睾吸虫病人淋巴细胞中扩增出约 70 0 bp重链 γ1 、γ3Fd段和轻链 κ、λ基因 ,分别和 p Com b3连接后成功导入 XL 1- blue,得到滴度为 7.5× 10 1 0 cfu/ ml,库容量为 5 .6× 10 6 噬菌体抗体库。结论　抗华支睾吸虫 Fab段噬菌体抗体库的构建 ,为进一步筛选抗华支睾吸虫循环抗原单克隆抗体奠定了基础。