Carroll D, Ajioka R S
Gene. 1980 Aug;10(3):273-81. doi: 10.1016/0378-1119(80)90056-6.
Single, 824 bp repeating units of xenopus laevis oocyte-type 5S DNA were inserted into the recombination vectors, lambda rva and lambda rvb. When the inserts had the same orientation with respect to the lambda chromosomes. Spi- imm434 recombinants were recovered by selection on a P2, lambda double lysogenic host. Because of the structure of the vectors, the crossover point in each recombinant must lie completely within the 5S DNA insert. The physical characteristics of these recombinants were determined by examination of restriction enzyme digests. By use of RecA mutant hosts and the Red- vector, lambda rvc, recombination frequencies were measured separately for the bacterial and phage systems. Some of the recombination events resulted in 5S DNA inserts of altered length due to unequal crossovers within repeated sequences in the 5S DNA spacer. The occurrence of just such events in frog 5S DNA had been predicted, based on the structure of 5S DNA and evolutionary considerations.
将非洲爪蟾卵母细胞型5S DNA的单个824 bp重复单元插入重组载体λrva和λrvb中。当插入片段相对于λ染色体具有相同方向时，通过在P2、λ双溶原宿主上进行选择来回收Spi-imm434重组体。由于载体的结构，每个重组体中的交叉点必须完全位于5S DNA插入片段内。通过检查限制性酶切消化来确定这些重组体的物理特性。利用RecA突变宿主和Red载体λrvc，分别测量细菌和噬菌体系统的重组频率。由于5S DNA间隔区重复序列内的不等交换，一些重组事件导致5S DNA插入片段长度改变。基于5S DNA的结构和进化考虑，已经预测到青蛙5S DNA中恰好会发生这样的事件。
