Genomic organization of low copy number sequences that are associated with deca-satellite DNA in the monkey genome.

A previously described segment of African green monkey DNA (cloned in phage lambda MkA) contains deca-satellite linked to DNA sequences that are estimated to occur once per genome. Sequences homologous to the low copy number sequences in lambda MkA are also associated with species-specific satellite DNAs in the human and mouse genomes. A second clone, lambda Mk8, contains a monkey DNA region that is colinear and homologous to a portion of the low copy number sequences in lambda MkA, but no satellite sequences. The two cloned segments are markedly different starting at a point proximal to the satellite DNA region in lambda MkA. DNA-blotting experiments indicate that lambda Mk8 but not lambda MkA represents the typical genomic organization and that the low copy number segments occur only once per haploid genome. The data suggest that rearrangements such as deletions or inversions occurring in monkey cells account in part for the structure of lambda MkA. Additional rearrangements may have occurred during cloning in E. coli. This unique chromosomal region may be particularly susceptible to recombination.