Gene transfer and expression in progeny after intravenous DNA injection into pregnant mice

Abstract

Several methods that enable foreign genes to be transferred directly into germ cells and adult animals have been developed, which have stimulated great interest in manipulating genes in vivo. However, there have been no methods available for introducing genes into fetuses. We report here that a single intravenous injection of expression plasmid: lipopolyamine complexes into pregnant mice resulted in successful gene transfer into the embryos. The transgenes thus introduced were expressed in the fetuses and newborn progeny. This simple and new method of gene transfer into embryos will facilitate rapid analysis of transgene effects in the fetuses and will be useful for studying gene-deficient animal models to gain transgene functions at desired stages of embryogenesis.

Nonviral gene transfer into fetal mouse livers (a comparison between the cationic polymer PEI and naked DNA)

“…[4][5][6][7] However, since viral vectors often exhibit side-effects, 8,9 safety concerns have led to the investigation of nonviral vectors as alternative approaches. 10,11 In the present study, the cationic polymer polyethylenimine (PEI) was used for intrauterine gene transfer. PEI's ability to condense and deliver DNA to cells has been extensively characterized in vivo, [12][13][14][15] but the applicability of this substance for prenatal gene transfer has not been addressed to date.…”

Temporally regulated expression patterns following in utero adenovirus-mediated gene transfer

“…[9][10][11] Although not delivered directly to the embryo, administration of vectors intravascularly to the pregnant mother has been reported to result in embryonic gene transfer: Kass-Eisler et al 12 reported injecting pregnant female rats with a recombinant adenovirus at 12 days gestation and found low levels of transgene expression 1 day after birth. Tsukamoto et al 13 injected expression plasmids complexed to lipopolyamine into the tail veins of pregnant mice and found the gene present in pups up to 1 month after birth. Other methods of fetal gene transfer have included: ex vivo retrovirus-transduced fetal hematopoietic cells which were re-infused in the donor fetus with intermittent detection of transgene activity post-natally; 14 intraperitoneal, retrovirus injection into fetal and adult rats; 15 intraplacental injection at a single developmental time-point; 16 and introduction of normal fetal liver cells or retrovirus-transduced cultured placental cells into the fetal placenta.…”

Possible mechanism of gene transfer into early to mid-gestational mouse fetuses by tail vein injection

“…Alternatively, the introduction of plasmid DNA into the circulation of pregnant mice has been proposed by Tsukamoto et al 14 as a different route for fetal gene delivery. Tsukamoto et al 14 demonstrated that with this simple technique, a wide variety of internal tissues of mid-gestational fetuses (treated at E 8.5) was transfected by exogenous plasmid DNA.…”

“…Tsukamoto et al 14 demonstrated that with this simple technique, a wide variety of internal tissues of mid-gestational fetuses (treated at E 8.5) was transfected by exogenous plasmid DNA. Furthermore, using this technique all of the treated embryos at embryonic day (E) 8.5 were transfected.…”

“…Furthermore, using this technique all of the treated embryos at embryonic day (E) 8.5 were transfected. 14 There are some major shortcomings concerning this method including loss of vector DNA to maternal tissues and undesirable gene delivery to the mother. However, there also are merits such as the ability to transfect multiple embryos and a variety of embryonic tissues in one treatment and requirement of neither skills in handling of viral DNA, nor surgical dissection.…”