| Abstract: | The development and regeneration of the pancreas is of considerable interest because of the role of these processes in
pancreatic diseases, such as diabetes. Here, we sought to develop a large animal model in which the pancreatic cell lineage
could be tracked. The pancreatic and duodenal homeobox-1 (Pdx1) gene promoter was conjugated to Venus, a
green fluorescent protein, and introduced into 370 in vitro-matured porcine oocytes by intracytoplasmic
sperm injection-mediated gene transfer. These oocytes were transferred into four recipient gilts, all of which became
pregnant. Three gilts were sacrificed at 47–65 days of gestation, and the fourth was allowed to farrow. Seven of 16 fetuses
obtained were transgenic (Tg) and exhibited pancreas-specific green fluorescence. The fourth recipient gilt produced a litter
of six piglets, two of which were Tg. The founder Tg offspring matured normally and produced healthy first-generation (G1)
progeny. A postweaning autopsy of four 27-day-old G1 Tg piglets confirmed the pancreas-specific Venus expression.
Immunostaining of the pancreatic tissue indicated the transgene was expressed in β-cells. Pancreatic islets from Tg pigs were
transplanted under the renal capsules of NOD/SCID mice and expressed fluorescence up to one month after transplantation. Tg
G1 pigs developed normally and had blood glucose levels within the normal range. Insulin levels before and after sexual
maturity were within normal ranges, as were other blood biochemistry parameters, indicating that pancreatic function was
normal. We conclude that Pdx1-Venus Tg pigs represent a large animal model suitable for research on
pancreatic development/regeneration and diabetes. |
