In our previous study, we demonstrated that pigs expressing neonatally lethal phenotype induced by genetic modification could be rescued by induction of chimerism by using blastocyst complementation. Here, we show that the obtained chimeric pigs can faithfully transmit the genotype, which is the cause of the lethal traits, to progenies.
Cloned embryos (male) of pigs showing the phenotype of pancreatogenesis deficiency by expression of the Pdx1-Hes1 gene were complemented with cloned embryos derived from three types of female pigs (humanized Kusabira-Orange transgenic, Pdx1-Venus transgenic, and coat colored WT) to produce six chimeric boars.
Except for one, all chimeric boars grew normally and reached sexual maturity. A total of 120 fetuses and piglets were produced by mating the five chimeric boars with 12 WT females. Analysis of 82 fetuses (day 47109) and 38 piglets showed that 61 (50.8%) were Pdx1-Hes1 transgenic, which inherited the phenotype of pancreatogenesis deficiency. The average birth weight of the transgenic piglets was significantly lighter than that of the non-transgenic piglets (906.5±40.8 g vs 1247.1±41.7 g; P<0.01). All transgenic piglets showed a high glucose level of 400 mg/dl or more, and died by several days. Our results demonstrated that the chimeric boars produced by blastocysts complementation of Pdx1-Hes1 transgenic-cloned embryos sired fetuses/piglets with the apancreatic phenotype in a Mendelian fashion. Thus, fetuses/piglets expressing lethal traits such as organogenesis deficiency are potential and powerful tools for research on regenerative medicine. This study was supported by JST, ERATO, Nakauchi Stem Cell and Organ Regeneration Project, and Meiji University International Institute for Bio-Resource Research (MUIIBR).
02 - 04 Sep 2014
World Congress of Reproductive Biology