Temporary developmental arrest after storage of fertilized mouse oocytes at 4 degrees C: effects on embryonic development, maternal mRNA processing and cell cycle.
The aim of this study was to examine whether fertilized mouse oocytes can survive after short-term incubation (for 6-48 h) at 4 degrees C. When fertilized oocytes of ICR and C57BL/6 (B6) strain were incubated at 4 degrees C and returned to normal culture conditions (37 degrees C), development of these 4 degrees C-treated embryos for up to 12 h (for ICR) to blastocyst stage did not differ from that of untreated oocytes. Even 4 degrees C-treated embryos for 48 h developed to blastocysts at relatively good rates (33.3% for ICR and 50.8% for B6). The in vivo development of 4 degrees C-treated embryos for 12, 24 and 36 h to fetal stage was similar to that of untreated ones. BrdU labelling assay revealed temporary cessation of DNA replication in 4 degrees C-treated fertilized oocytes. Post-fertilization events including cytoplasmic polyadenylation of maternal mRNAs, mRNA degradation of a cell cycle-related gene and elevated mRNA expression of zygotic gene activation-related genes were temporarily suppressed in 4 degrees C-treated embryos. These findings indicate that 4 degrees C-treatment of fertilized murine oocytes results in temporary cessation of molecular events. We also show that 4 degrees C-treated fertilized oocytes for 12 h can be used for preparation of transgenic mice.
Sakurai
Takayuki
T
Division of Basic Molecular Science and Molecular Medicine, School of Medicine, The Institute of Medical Sciences, Tokai University, Bohseidai, Isehara, Kanagawa 259-1193, Japan. sakurai@is.icc.u-tokai.ac.jp
Kimura
Minoru
M
Sato
Masahiro
M
D000818:Animals; D002453:Cell Cycle; D004261:DNA Replication; D047108:Embryonic Development; D005260:Female; D005298:Fertility; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D008822:Mice, Transgenic; D009865:Oocytes / Q000166:cytology / Q000254:growth & development; D026723:Polyadenylation; D012333:RNA, Messenger / Q000378:metabolism*; D012034:Refrigeration; D016160:Retinoblastoma Protein / Q000235:genetics; D013696:Temperature; D015053:Zygote / Q000166:cytology / Q000254:growth & development*
D012333:RNA, Messenger; D016160:Retinoblastoma Protein