title: Inactivation of the murine pyruvate dehydrogenase (Pdha1) gene and its effect on early embryonic development.
abstract: A deficiency of pyruvate dehydrogenase complex (PDC) in humans results in lactic acidosis and neurological dysfunction that frequently results in death during infancy. Using gene targeting technology, a silent mutation was introduced into the murine X-linked Pdha1 gene that encodes the alpha subunit of the pyruvate dehydrogenase or E1 component of the complex. Two loxP sequences were introduced into intronic sequences flanking exon 8 to generate the Pdha1(flox8) allele. In vitro studies in embryonic stem cells demonstrated that deletion of exon 8 ablated PDC activity. Homozygous Pdha1(flox8) females were bred with male mice carrying a wild-type Pdha1 allele and a transgene that ubiquitously expresses the Cre recombinase to produce progeny with a deletion in exon 8, Pdha1(Deltaex8). The majority of progeny were found to be mosaic with the presence of both the flox and deleted alleles, and there were no apparent phenotypic effects associated with the null allele. The mosaic mice were interbred to increase the degree of mosaicism for the Pdha1(Deltaex8) allele in the subsequent generation, resulting in a significantly smaller litter size (54% reduction). Embryos carrying predominantly the Pdha1(Deltaex8) allele were found to be globally delayed in development by 9.5 days postcoitus, with resorption occurring over the following several days. These findings demonstrate an essential role for oxidative metabolism of glucose during the early postimplantation period of prenatal development.
authors.affiliation: Department of Biochemistry, State University of New York at Buffalo, 3435 Main Street, Buffalo, NY 14214, USA.
authors.forename: M T
authors.initials: MT
authors.lastname: Johnson
authors.forename: S
authors.initials: S
authors.lastname: Mahmood
authors.forename: S L
authors.initials: SL
authors.lastname: Hyatt
authors.forename: H S
authors.initials: HS
authors.lastname: Yang
authors.forename: P D
authors.initials: PD
authors.lastname: Soloway
authors.forename: R W
authors.initials: RW
authors.lastname: Hanson
authors.forename: M S
authors.initials: MS
authors.lastname: Patel
mesh_terms: D000483:Alleles; D000818:Animals; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D005314:Embryonic and Fetal Development / Q000235:genetics*; D005260:Female; D017353:Gene Deletion; D020868:Gene Silencing; D005838:Genotype; D019426:Integrases / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009030:Mosaicism; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D030481:Pyruvate Dehydrogenase (Lipoamide) / Q000235:genetics*; D011995:Recombination, Genetic; D013997:Time Factors; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D014764:Viral Proteins; D030481:Pyruvate Dehydrogenase (Lipoamide); C045073:Cre recombinase; D019426:Integrases