TY - JOUR
T1 - Mitochondrial DNA instability and peri-implantation lethality associated with targeted disruption of nuclear respiratory factor 1 in mice
AU - Huo, L.
AU - Scarpulla, R. C.
PY - 2001
Y1 - 2001
N2 - In vitro studies have implicated nuclear respiratory factor 1 (NRF-1) in the transcriptional expression of nuclear genes required for mitochondrial respiratory function, as well as for other fundamental cellular activities. We investigated here the in vivo function of NRF-1 in mammals by disrupting the gene in mice. A portion of the NRF-1 gene that encodes the nuclear localization signal and the DNA-binding and dimerization domains was replaced through homologous recombination by a β-galactosidase-neomycin cassette. In the mutant allele, β-galactosidase expression is under the control of the NRF-1 promoter. Embryos homozygous for NRF-1 disruption die between embryonic days 3.5 and 6.5. β-Galactosidase staining was observed in growing oocytes and in 2.5- and 3.5-day-old embryos, demonstrating that the NRF-1 gene is expressed during oogenesis and during early stages of embryogenesis. Moreover, the embryonic expression of NRF-1 did not result from maternal carryover. While most isolated wild-type and NRF-1+/- blastocysts can develop further in vitro, the NRF-1-/- blastocysts lack this ability despite their normal morphology. Interestingly, a fraction of the blastocysts from heterozygous matings had reduced staining intensity with rhodamine 123 and NRF-1-/- blastocysts had markedly reduced levels of mitochondrial DNA (mtDNA). The depletion of mtDNA did not coincide with nuclear DNA fragmentation, indicating that mtDNA loss was not associated with increased apoptosis. These results are consistent with a specific requirement for NRF-1 in the maintenance of mtDNA and respiratory chain function during early embryogenesis.
AB - In vitro studies have implicated nuclear respiratory factor 1 (NRF-1) in the transcriptional expression of nuclear genes required for mitochondrial respiratory function, as well as for other fundamental cellular activities. We investigated here the in vivo function of NRF-1 in mammals by disrupting the gene in mice. A portion of the NRF-1 gene that encodes the nuclear localization signal and the DNA-binding and dimerization domains was replaced through homologous recombination by a β-galactosidase-neomycin cassette. In the mutant allele, β-galactosidase expression is under the control of the NRF-1 promoter. Embryos homozygous for NRF-1 disruption die between embryonic days 3.5 and 6.5. β-Galactosidase staining was observed in growing oocytes and in 2.5- and 3.5-day-old embryos, demonstrating that the NRF-1 gene is expressed during oogenesis and during early stages of embryogenesis. Moreover, the embryonic expression of NRF-1 did not result from maternal carryover. While most isolated wild-type and NRF-1+/- blastocysts can develop further in vitro, the NRF-1-/- blastocysts lack this ability despite their normal morphology. Interestingly, a fraction of the blastocysts from heterozygous matings had reduced staining intensity with rhodamine 123 and NRF-1-/- blastocysts had markedly reduced levels of mitochondrial DNA (mtDNA). The depletion of mtDNA did not coincide with nuclear DNA fragmentation, indicating that mtDNA loss was not associated with increased apoptosis. These results are consistent with a specific requirement for NRF-1 in the maintenance of mtDNA and respiratory chain function during early embryogenesis.
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U2 - 10.1128/MCB.21.2.644-654.2001
DO - 10.1128/MCB.21.2.644-654.2001
M3 - Article
C2 - 11134350
AN - SCOPUS:0035169827
SN - 0270-7306
VL - 21
SP - 644
EP - 654
JO - Molecular and cellular biology
JF - Molecular and cellular biology
IS - 2
ER -