Stability of a functional murine satellite DNA-based artificial chromosomeacross mammalian species

A 60-Mb murine chromosome consisting of murine pericentric satellite DNA an d two bands of integrated marker and reporter genes has been generated de n ovo in a rodent/human hybrid cell line (mM2C1). This prototype mammalian ar tificial chromosome platform carries a normal centromere, and the expressio n of its beta-galactosidase reporter gene has remained stable under selecti on for over 25 months. The novel chromosome was transferred by a modified m icrocell fusion method to mouse [L-M(TK-)], bovine (P46) and human (EJ30) c ell lines. In all cases, the chromosome remained structurally and functiona lly intact under selection for periods exceeding 3 months from the time of transfer into the new host. In addition, the chromosome was retained in thr ee first-generation tumours when L-M(TK-) cells containing the chromosome w ere xenografted in severe combined immunodeficiency mice. These data suppor t that a murine satellite DNA-based artificial chromosome can be used as a functional mammalian artificial chromosome and can be maintained in vivo an d in cells of heterologous species in vitro.