Sequence and biological activity of chicken snoN cDNA clones

cDNA clones of the ski-related gene, sno, were isolated from a chicken cDNA library and sequenced. In contrast to the human system, from which two forms of sno cDNAs have been isolated, we obtained only one type of chicken sno cDNA, that encoding snoN. The coding region for chicken snoN was inserted into the retroviral vectors RCAS(A) and RCASBP(A) and introduced into chicken embryo fibroblasts (CEFs) or quail embryo cells (QECs). Like the various forms of ski, snoN appears to be localized in the nucleus, and high levels of snoN expression cause transformation of CEFs and muscle differentiation of QECs. In contrast to ski however, low-level expression of snoN cannot induce transformation, and is only weakly myogenic.