期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1978
卷号：75
期号：9
页码：4268-4270
DOI：10.1073/pnas.75.9.4268
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The mutated base in the am3 lysis-defective mutant of the bacteriophage phiX174 has been corrected by a combined in vitro enzymatic DNA synthesis and in vivo replication of the heteroduplex product. Chemically synthesized oligodeoxyribonucleotides carrying the wild-type sequence have been used to prime DNA synthesis with am3 phiX174 DNA serving as a template. The resultant semisynthetic heteroduplex composed of an am3(+) strand and a wild-type (-) strand, with one mismatched base pair at position 587 on the phiX174 DNA sequence, was used to infect spheroplasts. The progeny phage were analyzed by a parallel plaque assay on wild-type host, Escherichia coli C, to screen for wild-type phenotype, and on E. coli HF4714, an amber suppressor strain, to determine the total progeny phage. When a 23-base-long synthetic primer was used, about one-third of total progeny were found to be wild type. Shorter primers yielded lower percentages of wild type; they also had poorer priming activity.
