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DNA重组技术的发展日新月异。作为一类新的DNA克隆载体,丝状单链DNA噬菌体迅速发展起来。由于其具有显著超过其它双链DNA载体的某些优点,故其在基因研究中的应用前景越来越广阔。单链DNA噬菌体的生物学成熟的单链DNA噬菌体M_(13)、fd和fl,长约1微米,呈细丝状。其DNA为单链环状,6.4kb,含8个基因.M_(13)和fd的全序列已测定,分别含6407个和6408个核苷酸,二者有97％的同源性;fl序列尚未全知,但据信,它甚至比fd更接近M_(13)。它们对大肠杆菌(E.coli)的感染是雄专一性的。感染后,在寄主细胞中成为环状双链DNA,即复制型(RF)DNA。每个细胞中有50～100个拷贝,并不断排出成熟的噬菌体颗粒到细胞外面去。这些噬菌
The development of recombinant DNA technology with each passing day. As a new type of DNA cloning vector, filamentous single-stranded DNA phage rapidly developed. Due to its significant advantages over other double-stranded DNA vectors, its application prospect in gene research is more and more broad. Single-stranded DNA phage biologically mature single-stranded DNA phage M_ (13), fd and fl, about 1 micron filamentous. The DNA was single-stranded, 6.4kb, containing 8 genes.The complete sequences of M_ (13) and fd have been determined, respectively, containing 6407 and 6408 nucleotides, both 97% homology; fl The sequence is not yet known, but it is believed that it is even closer to M_ (13) than fd. Their infection with E. coli is monosomic. After infection, it becomes a circular double-stranded DNA in host cells, ie, replication-type (RF) DNA. Each cell has 50 to 100 copies, and continue to discharge mature phage particles to the outside of the cell. These phages