RNA FISH to Study Zygotic Genome Activation in Early Mouse Embryos

SummaryMinor and major zygotic genome activation (ZGA) are crucial for preimplantation development. During this process, histone variants and methylation influence chromatin accessibility and consequently regulated the expression of zygotic genes. However, the detailed exchanges of these modifications during ZGA remain to be determined. In the present study, the epigenetic modifications of histone 3 on lysine 9 (H3K9), 27 (H3K27) and 36 (H3K36), as well as four histone variants were determined during minor and major ZGA and in post-ZGA stages of mouse embryos. Firstly, microH2A1, H3K27me3 and H3K36me3 were asymmetrically stained in the female pronucleus during minor ZGA but lost staining in major ZGA. Secondly, H3K9me2 and H3K9me3 were strongly stained in the female pronucleus, but weakly stained in the male pronucleus and disappeared after ZGA. Thirdly, H2A.Z and H3.3 were symmetrically stained in male and female pronuclei during minor ZGA. Moreover, H3K27me2 was not statistically changed during mouse early development, while H3K36me2 was only detected in 2- and 4-cell embryos. In conclusion, our data revealed dynamics of histone methylation and variants during mice ZGA and provided details of their exchange in mice embryogenesis. Moreover, we further inferred that macroH2A1, H2A.Z, H3K9me2/3 and H3K27me2/3 may play crucial roles during mouse ZGA.

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Regulated expression of TAF1 in 1-cell mouse embryos

Zygote ◽

10.1017/s0967199406003704 ◽

2006 ◽

Vol 14 (3) ◽

pp. 209-215 ◽

Cited By ~ 7

Author(s):

Kai Wang ◽

Feng Sun ◽

Hui Z. Sheng

Keyword(s):

Immunofluorescence Assay ◽

Mouse Embryos ◽

Zygotic Genome Activation ◽

Transcriptional Silence ◽

Transcription Machinery ◽

High Level ◽

Genome Activation ◽

Combined Deficiency ◽

General Transcription Machinery ◽

Zygotic Genome

SummaryTATA binding protein (TBP) associated factor 1 (TAF1) is a member of the general transcription machinery. Interference in the function of TAF1 causes a broad transcriptional defect in early development. To explore possible roles of TAF1 in embryonic transcriptional silence and zygotic genome activation, we examined the expression of TAF1 in 1-cell mouse embryos. Using an immunofluorescence assay, TAF1 was not detected in embryos in the first few hours after fertilization. TAF1 appeared in pronuclei 6 h post-fertilization and reached a relatively high level before zygotic genome activation. These data show that besides TBP, another critical member of the general transcription machinery such as TAF1 is also absent or at an extremely low level at the outset of development. Combined deficiency in critical members of the general transcription machinery may account for embryonic transcriptional silence.

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Detection of RNA Polymerase II in Mouse Embryos During Zygotic Genome Activation Using Immunocytochemistry

Methods in Molecular Biology - Zygotic Genome Activation ◽

10.1007/978-1-4939-6988-3_10 ◽

2017 ◽

pp. 147-159 ◽

Cited By ~ 1

Author(s):

Irina O. Bogolyubova ◽

Dmitry S. Bogolyubov

Keyword(s):

Rna Polymerase ◽

Rna Polymerase Ii ◽

Mouse Embryos ◽

Zygotic Genome Activation ◽

Genome Activation ◽

Zygotic Genome

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Characterization of zygotic genome activation-dependent maternal mRNA clearance in mouse

Nucleic Acids Research ◽

10.1093/nar/gkz1111 ◽

2019 ◽

Vol 48 (2) ◽

pp. 879-894 ◽

Cited By ~ 5

Author(s):

Qian-Qian Sha ◽

Ye-Zhang Zhu ◽

Sen Li ◽

Yu Jiang ◽

Lu Chen ◽

...

Keyword(s):

De Novo ◽

Mouse Embryos ◽

Developmental Competence ◽

Preimplantation Embryos ◽

Zygotic Genome Activation ◽

Cell Stage ◽

Maternal Mrna ◽

Maternal Transcripts ◽

Genome Activation ◽

Zygotic Genome

Abstract An important event of the maternal-to-zygotic transition (MZT) in animal embryos is the elimination of a subset of the maternal transcripts that accumulated during oogenesis. In both invertebrates and vertebrates, a maternally encoded mRNA decay pathway (M-decay) acts before zygotic genome activation (ZGA) while a second pathway, which requires zygotic transcription, subsequently clears additional mRNAs (Z-decay). To date the mechanisms that activate the Z-decay pathway in mammalian early embryos have not been investigated. Here, we identify murine maternal transcripts that are degraded after ZGA and show that inhibition of de novo transcription stabilizes these mRNAs in mouse embryos. We show that YAP1-TEAD4 transcription factor-mediated transcription is essential for Z-decay in mouse embryos and that TEAD4-triggered zygotic expression of terminal uridylyltransferases TUT4 and TUT7 and mRNA 3′-oligouridylation direct Z-decay. Components of the M-decay pathway, including BTG4 and the CCR4-NOT deadenylase, continue to function in Z-decay but require reinforcement from the zygotic factors for timely removal of maternal mRNAs. A long 3′-UTR and active translation confer resistance of Z-decay transcripts to M-decay during oocyte meiotic maturation. The Z-decay pathway is required for mouse embryo development beyond the four-cell stage and contributes to the developmental competence of preimplantation embryos.

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