CONSTRUCTION OF YAC-BASED MAMMALIAN ARTIFICIAL CHROMOSOMES

To construct a mammalian artificial chromosome (MAC), telomere repeats and selectable markers were introduced into a 100 kb yeast artificial chromosome (YAC) containing human centromeric DNA. This YAC, which ha s a regular repeat structure of alpha-satellite DNA and centromere pro tein B (CENP-B) boxes, efficiently formed MACs that segregated accurat ely and bound CENP-B, CENP-C, and CENP-E. The MACs appear to be about 1-5 Mb in size and contain YAC multimers. Structural analyses suggest that the MACs have not acquired host sequences and were formed by a de novo mechanism. The accurate segregation of the MACs suggests they ha ve potential as vectors for introducing genes into mammals.