Onset of paternal gene activation in early mouse embryos fertilized with transgenic mouse sperm.
We investigated the onset of paternal gene expression in the early mouse embryo. We obtained transgenic mouse embryos by fertilizing BD (C57BL/6N x DBA) F1 hybrid female oocytes in vitro, with sperm from homozygous transgenic males carrying integrated chicken beta-actin promoter-driven firefly luciferase cDNA. We then examined the RNA and protein synthesis of the luciferase gene in embryos from the 1- to 2-cell stage. RNA transcripts of the luciferase gene were first detected in the 1-cell stage embryos as early as 13 hr postinsemination, just prior to elongation. By photon-count imaging, functional luciferase was identified at the 2-cell stage 23 hr postinsemination. These findings indicate that the paternal endogenous gene is already transcribed in the late 1-cell embryos, although paternally derived protein is not synthesized until the 2-cell stage. Therefore, these results suggest that the embryonic gene is activated as early as the late 1-cell stage.
Matsumoto
K
K
NT Science Co., Ltd., Tokyo, Japan.
Anzai
M
M
Nakagata
N
N
Takahashi
A
A
Takahashi
Y
Y
Miyata
K
K
D000199:Actins / Q000096:biosynthesis; D000818:Animals; D001483:Base Sequence; D001755:Blastocyst / Q000378:metabolism*; D002645:Chickens; D001517:Coleoptera / Q000201:enzymology; D017931:DNA Primers; D005260:Female; D005307:Fertilization in Vitro; D005786:Gene Expression Regulation; D008156:Luciferases / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009865:Oocytes / Q000502:physiology; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D015183:Restriction Mapping; D013094:Spermatozoa / Q000502:physiology*; D015533:Transcriptional Activation
D000199:Actins; D017931:DNA Primers; D011993:Recombinant Fusion Proteins; D008156:Luciferases