The 137th RIKEN BRC SEMINAR
Role of Newly Discovered Oocyte Factors in Regulating Maternal-zygotic Transition in Mammals
Date: Oct 28(Fri.) 2016. 16:00 - (JST)
Place: Moriwaki Hall (BioResource Center Main Building 1F)
The invited lecturer
Dr. Heng-Yu Fan
Life Sciences Institute
Zhejiang University, Hangzhou, China
Zhejiang University, Hangzhou, China
Summary
The mRNAs stored in oocytes undergo general decay during maternal-zygotic
transition (MZT), and their stability is tightly interconnected with meiotic cell
cycle progression. We identified B-cell translocation gene-4 (BTG4) as an MZT
licensing factor in mouse. BTG4 bridged CNOT7, a catalytic subunit of CCR4-
NOT deadenylase, to eIF4E, a key translation initiation factor, and played a permissive
role in maternal mRNA decay. Oocyte intrinsic MAPK cascade triggers
translation of Btg4 mRNA stored in fully-grown oocytes by targeting its
3'-untranslated region, thereby couples CCR4-NOT deadenylase-mediated maternal
mRNA decay with oocyte maturation and fertilization. On the other hand,
maternally accumulated YAP in oocyte is crucial for zygotic genome activation.
These observations provide insights into the mechanisms of zygotic genome
activation, and suggest potential implications of YAP activators in improving the
developmental competence of cultured embryos in human assisted reproduction
and animal biotechnology.