MAPABILITY OF VERY CLOSE MARKERS OF BACTERIOPHAGE Λ

[摘要] Recombinant frequency was compared with nucleotide distance in crosses involving markers in either the P RM or the cy region of phage λ. For each pair of markers, we performed reciprocal four-factor crosses of the following types: (I) A + m 1 + m 2- B - × A - m 1 - m 2+ B +; and (II) A + m 1 - m 2+ B - × A - m 1 + m 2- B +. In crosses of type I, the frequency of A + m 1 + m 2+ B + recombinants among total (selected) A + B + progeny was directly proportional to nucleotide distance between m 1 and m 2 in the range from 3 to 160 nucleotides. When less than three nucleotides separated m 1 and m 2, the measured yields of m 1+ m 2+ recombinants were significantly depressed.

[学科分类] 医学（综合）