title: Functional analysis of nocturnin, a circadian deadenylase, at maternal-to-zygotic transition in mice.
abstract: Degradation of maternally stored mRNAs after fertilization is an essential process for mammalian embryogenesis. Maternal mRNA degradation depending on deadenylases in mammalian early embryos has been mostly speculated, rather than directly demonstrated. Previously, we found that gene expression of nocturnin, which functions as a circadian clock-controlled deadenylase in mammalian cells, was clearly changed during the maternal-to-zygotic transition (MZT). Here, we investigated the possible role of nocturnin during mouse MZT. First, we examined the expression profile and localization of nocturnin in mouse oocytes and early embryos. The abundance of Nocturnin mRNA level was significantly decreased from the MII to 4-cell stages and slightly increased from the 8-cell to blastocyst stages, whereas the Nocturnin protein level was almost stable in all examined cells including GV and MII oocytes and early embryos. Nocturnin was localized in both the cytoplasm and the nucleus of all examined cells. We then examined the effect of loss or gain of Nocturnin function on early embryonic development. Knockdown of Nocturnin by injection of Nocturnin antisense expression vector into 1-cell embryos resulted in the delay of early embryonic development to the early blastocyst stage. Moreover, Nocturnin-overexpressed embryos by injection of Nocturnin expression vector impaired their development from the 1-cell to 2-cell or 4-cell stages. These results suggest that precise expression of nocturnin is critical to proper development of early mouse embryos. Functional analysis of nocturnin may contribute to the understanding of the possible role of the deadenylase at mouse MZT.
authors: Laboratory of Molecular Developmental Biology, Graduate School of Biology-Oriented Science and Technology, Kinki University, Wakayama 649-6493, Japan.
authors: Satoshi
authors: S
authors: Nishikawa
authors: Yuki
authors: Y
authors: Hatanaka
authors: Mikiko
authors: M
authors: Tokoro
authors: Seung-Wook
authors: SW
authors: Shin
authors: Natsumi
authors: N
authors: Shimizu
authors: Takuji
authors: T
authors: Nishihara
authors: Rie
authors: R
authors: Kato
authors: Atsushi
authors: A
authors: Takemoto
authors: Tomoko
authors: T
authors: Amano
authors: Masayuki
authors: M
authors: Anzai
authors: Satoshi
authors: S
authors: Kishigami
authors: Yoshihiko
authors: Y
authors: Hosoi
authors: Kazuya
authors: K
authors: Matsumoto
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism; D002940:Circadian Rhythm; D003593:Cytoplasm / Q000378:metabolism; D046149:Embryo Culture Techniques; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D051379:Mice; D008813:Mice, Inbred ICR; D009687:Nuclear Proteins / Q000502:physiology*; D009865:Oocytes / Q000166:cytology; D011247:Pregnancy; D011270:Pregnancy, Animal; D013997:Time Factors; D014157:Transcription Factors / Q000502:physiology*; D015053:Zygote / Q000502:physiology*
chemical_list: D009687:Nuclear Proteins; D014157:Transcription Factors; C102804:nocturnin