Mice are the most commonly used laboratory animals for research, and some mouse stem cells, such as induced pluripotent stem cells, embryonic stem cells, and mesenchymal stem cells (MSCs), are also widely used in basic research. It is thus important to know if these stem cells maintain their genomic stability when cultured. Murine bone marrow-derived mesenchymal stem cells (BMSCs) appear to undergo spontaneous transformation in vitro. Murine adipose tissue-derived mesenchymal stem cells (ADSCs), like BMSCs, have the potential to differentiate into multiple lineages. In this study, we used G-banding, induction of multiple-lineage differentiation, flow cytometry, and nuclear transfer (NT), and found that murine ADSCs also displayed chromosomal instability in long-term culture. Furthermore, we performed NT using murine ADSCs to study the nuclear reprogramming ability of undifferentiated adult stem cells and to find a new efficient donor for NT. Using the stem cells did not increase the percentage of NT embryos that developed to the morula/blastocyst stage, compared with cloned embryos from cumulus cells. This may be because the stem cells displayed chromosomal instability. This is the first reported study of the use of ADSCs for NT in mice. ADSCs could provide an alternative donor cell type for NT in other species, with the advantages of easy harvesting involving little or no pain or trauma.