UBC is a polyubiquitin precursor responsible for the regulation of cell signaling pathways upon conjugation with various proteins. The cTVA transgene in this strain carries the human ubiquitin C (UBC) promoter/enhancer elements driving expression of a loxP-flanked destabilized green fluorescent protein (GFP) and polyadenylation sequence, followed by an avian specific retroviral receptor (TVA) gene derived from quail. Hemizygous mice are viable and fertile. Although GFP expression in UBC-expressing cells was anticipated, none is detected. This may be associated with the use of destabilized GFP and/or low expression levels. Cre-mediated excision of the floxed-GFP-STOP cassette results in TVA overexpression in UBC-expressing cells. Upon expression of TVA, these cells are capable of binding viruses with the envelope protein of avian sarcoma/leukosis virus subtype A (ASLV-A). These cTVA mice may be useful for infection by retroviruses, rabies virus, and other viruses with ASLV-A glycoproteins. The Jackson Laboratory 2024, used with permission.