P-body loss is concomitant with formation of a messenger RNA storage domain in mouse oocytes.
In mammalian somatic cells, several pathways that converge on deadenylation, decapping, and 5'-3' degradation are found in cytoplasmic foci known as P-bodies. Because controlled mRNA stability is essential for oocyte-to-zygote transition, we examined the dynamics of P-body components in mouse oocytes. We report that oocyte growth is accompanied by loss of P-bodies and a subcortical accumulation of several RNA-binding proteins, including DDX6, CPEB, YBX2 (MSY2), and the exon junction complex. These proteins form transient RNA-containing aggregates in fully grown oocytes with a surrounded nucleolus chromatin configuration. These aggregates disperse during oocyte maturation, consistent with recruitment of maternal mRNAs that occurs during this time. In contrast, levels of DCP1A are low during oocyte growth, and DCP1A does not colocalize with DDX6 in the subcortical aggregates. The amount of DCP1A markedly increases during meiosis, which correlates with the first wave of destabilization of maternal mRNAs. We propose that the cortex of growing oocytes serves as an mRNA storage compartment, which contains a novel type of RNA granule related to P-bodies.
Flemr
Matyas
M
Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
Ma
Jun
J
Schultz
Richard M
RM
Svoboda
Petr
P
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D003594:Cytoplasmic Granules / Q000378:metabolism*; D004722:Endoribonucleases; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D042541:Intracellular Space; D051379:Mice; D008810:Mice, Inbred C57BL; D046912:Multiprotein Complexes / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism*; D010053:Ovary / Q000254:growth & development / Q000378:metabolism; D011487:Protein Conformation; D012315:RNA Caps / Q000378:metabolism; D023121:RNA, Messenger, Stored / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000502:physiology; D012261:Ribonucleoproteins / Q000378:metabolism*; D013329:Structure-Activity Relationship; D015534:Trans-Activators / Q000378:metabolism*
D046912:Multiprotein Complexes; D012315:RNA Caps; D023121:RNA, Messenger, Stored; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D015534:Trans-Activators; D004722:Endoribonucleases; C466280:smad4-interacting protein SMIF, mouse