How soon can recombinant proteins/vaccines be produced by transgenic rabbits?
Transgenically produced proteins are secreted in the milk of females during lactation. Milking typically begins upon delivery of the offspring. Often, enough milk may be obtained from founders to evaluate the concentration of recombinant protein secretion, to begin characterizing the protein, to start purification process development. Larger milk quantities for preclinical batches preparation can be obtained from F1 transgenic females. The total time from transgene introduction to first natural lactation of founder female rabbits is about 6 months. In parallel, founders are crossbred with wild type rabbits in order to give birth to offspring and begin full-scale milk production. Those founders that are males must produce daughters and these daughters must have offspring of their own before full-scale milk collection may begin. The time to first lactation is about 12 months for transgenic lines derived from founders.
