Preimplantation-embryo-specific cell cycle regulation is attributed to the low expression level of retinoblastoma protein.
It is known that a characteristic of the mammalian preimplantation-embryo-specific cell cycle is the substantially shortened G1-phase, although the regulation mechanisms of the unique cell cycle remain unclear. In the present study, we first examined the presence of retinoblastoma (RB) tumor suppressor gene product throughout mouse preimplantation embryo development and found that the RB expression was down-regulated between the four-cell and morula stages. Furthermore, the overexpression of RB protein in the mouse embryos during this phase inhibited their development significantly. These results suggest that the absence of RB protein contributes to the preimplantation-embryo-specific cell cycle.
Laboratory of Applied Genetics, Department of Animal Resource Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, 113-8657 Tokyo, Japan. aa07157@mail.ecc.u-tokyo.ac.jp
Naoki
N
Iwamori
Kunihiko
K
Naito
Koji
K
Sugiura
Hideaki
H
Tojo
D000818:Animals; D001483:Base Sequence; D001755:Blastocyst / Q000166:cytology*; D002453:Cell Cycle; D017931:DNA Primers; D016193:G1 Phase; D005819:Genetic Markers; D051379:Mice; D008815:Mice, Inbred Strains; D016133:Polymerase Chain Reaction; D016160:Retinoblastoma Protein / Q000235:genetics*
D017931:DNA Primers; D005819:Genetic Markers; D016160:Retinoblastoma Protein