Abstract: Disclosed are nucleic acid sequences comprising a modified HIV Gag sequence, wherein the modified HIV Gag sequence comprises, from 5? to 3?, a matrix domain (MA), capsid (CA) domain, SP1 region, nucleocapsid (NC) domain, SP2 region, and p6 domain, wherein the modified HIV Gag sequence further comprises an exogenous sequence of interest between the NC domain and the SP2 region. Disclosed are methods of producing a recombinant lentivirus comprising transfecting a cell with a plasmid comprising the nucleic acid sequence of one or more of the disclosed nucleic acid sequences in combination with an envelope plasmid. Disclosed are methods of monitoring lentivirus assembly, budding, and/or maturation comprising transfecting a cell with a plasmid comprising any one of the disclosed nucleic acid sequences in combination with an envelope plasmid, wherein the exogenous sequence of interest encodes a detection agent.