In vivo genetic manipulation of the rat trophoblast cell lineage using lentiviral vector delivery.

In this report, we have adapted a lentiviral gene delivery technique for genetic modification of the rat trophoblast cell lineage. Blastocysts were incubated with lentiviral particles and transferred into the uteri of pseudopregnant female rats, harvested at various times during gestation, and then analyzed. Two test systems were evaluated: (1) delivery of an enhanced green fluorescent protein (EGFP) gene under the control of constitutive promoters to rat blastocysts; (2) delivery of EGFP short hairpin RNA (shRNA) to rat blastocysts constitutively expressing EGFP. Lentiviral packaged gene constructs were efficiently and specifically delivered to all trophoblast cell lineages. Additionally, lentiviral mediated transfer of shRNAs was an effective strategy for modifying gene expression in trophoblast cell lineages. This technique will permit the in vivo evaluation of "gain-of-function" and "loss-of-function" manipulations in the rat trophoblast cell lineage.