No abstract

Lentiviral gene constructs can be efficiently and specifically delivered to trophoblast cell lineages in rodents. In vivo genetic manipulation of trophoblast cell lines enables functional and developmental studies in the placenta. In this report we show that genetic modification can be produced in the extraembryonic tissues of rabbits by lentiviral gene constructs. When 8-16 cell stage embryos were injected with lentiviral particles, strong reporter gene expression resulted in the rabbit placenta. The expression pattern displayed some mosaicism. A strikingly high degree of mosaic GFP expression was detected in some parts of the yolk sac, which is a hypoblast-derived tissue. Whereas expression of the reporter gene construct was detected in placentas and yolk sacs, fetuses never expressed the transgene. As rabbits are an ideal model for functional studies in the placenta, our method would open new possibilities in rabbit biotechnology and placentation studies.

Focal segmental glomerulosclerosis (FSGS) is a potential cause of nephrotic syndrome both in humans and pet mammals. Glomerulopathy was reported earlier in green fluorescent protein (GFP) transgenic (TG) mice, but glomerulosclerosis has not been examined in GFP TG rabbits so far. In the present study, the potential manifestation of FSGS was investigated in both Venus TG rabbits generated by Sleeping Beauty (SB) transposition and age-matched control New Zealand White (NZW) rabbits. Venus protein fluorescence was detected by confocal microscopy and quantified by microplate reader. Urinalysis, haematology, serum biochemistry and renal histology were performed to assess the signs of FSGS. Higher levels of Venus fluorescence were determined in renal cortex samples than in the myocardium by both methods. Urinalysis revealed proteinuria in Venus heterozygote TG bucks, while Venus homozygote TG bucks developed microscopic haematuria. Supporting the urinalysis data, the histological findings of FSGS (glomerulomegaly and sclerotic glomeruli) were observed in renal cortex sections of Venus TG rabbits. Taken together, Venus TG bucks were diagnosed with FSGS; thus, this type of glomerulopathy could be a common disease in TG animals overexpressing GFP.