Pathway Human Homo sapiens

M-decay: degradation of maternal mRNAs by maternally stored factors

R-HSA-9820841 in Reactome release 97: under Maternal to zygotic transition (MZT), with 33 genes placed in it by the mapping files and 0 child pathways in the hierarchy.

The same number in the other species

Reactome writes the mouse and rat events it infers from a human pathway under the human number with the species token. A door opens only where that species' own list in this release holds the id; neither of the other two lists holds it. Whether the event was inferred from this one is what the record says.

The record
The genes
Parents and children

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This page reads the pathway's record from its source while you read the rest; with scripts off the card stays at its loading line. Reload with scripts on to see it, or open the source's own page from the link in the card.

01The record

Reactome's own record of this pathway

What this tells you

The pathway list, the hierarchy and the genes on this page are read from the files Reactome publishes for Reactome release 97, built into this site on 2026-09-09: the pathway list, the hierarchy relationship file and the two gene mapping files. The record card is the one live read, Reactome's own record of this pathway.

Reactome's download page describes the mapping files: Mapping files link the source database identifier to the lowest level pathway diagram or subset of the pathway, all levels of the pathway hierarchy or database identifier to all reactions. [R13] The gene list here is the all-levels mapping of NCBI Gene ids, filled from the all-levels mapping of Ensembl ids where the NCBI file has no row for a gene; each row names which file it came from by the shape of its source id. Each row carries the evidence codes the file writes for it, as written and unranked, and both where the file writes both; no page of Reactome's documentation the survey read defines the codes, so this page does not expand them. A gene id the identity files do not name is kept as the source's own id with no door rather than turned into a symbol.

On citing what a search finds, Reactome says: It should be remembered that while we strive to contain the most current and accurate data, Reactome should not be used in citations where other primary sources of information are available. [R12] The record card prints the literature Reactome attaches to a curated pathway for that reason. The data are public domain: All data in the Reactome database and files derived from that data are licensed under the Creative Commons Public Domain Dedication (CC0). User may copy, modify, and distribute these data, even for commercial purposes, without asking for permission. Attribution is encouraged but not required. [R10] The pathway illustrations are licensed apart, under CC BY 4.0, and none is shown here.

A gene on this list is one Reactome places in this pathway in this release, and that is all the row says: it does not say the gene is expressed in a tissue or associated with a disease, which are the other two explorers' questions, read from other sources. Reactome's papers of record are [R01] [R02].

[R01] Ragueneau E, Gong C, Sinquin P, Sevilla C, Beavers D, Grentner A, et al. (2026). The Reactome Knowledgebase 2026. Nucleic Acids Research 54:D673-D681. PMID 41251150, doi 10.1093/nar/gkaf1223.
[R02] Milacic M, Beavers D, Conley P, Gong C, Gillespie M, Griss J, et al. (2024). The Reactome Pathway Knowledgebase 2024. Nucleic Acids Research 52:D672-D678. PMID 37941124, doi 10.1093/nar/gkad1025.
[R10] Reactome, reactome.org. License Agreement. https://reactome.org/license, read 2026-09-09.
[R12] Reactome, reactome.org. Citing us. https://reactome.org/cite, read 2026-09-09.
[R13] Reactome, reactome.org. Download. https://reactome.org/download-data, read 2026-09-09.

Stable id: R-HSA-9820841.1
Class: Pathway
Species: Homo sapiens (human)
Inferred: no: a curated human pathway
Disease pathway: no
Released: 2023-09-13
Events inside: 7, counted from the record

Maternal transcripts are transcribed from the maternal genome and accumulate in the oocyte during oogenesis. A subset of these maternal transcripts is degraded during later development of the unfertilized oocyte and after fertilization of the oocyte. Maternal decay of maternal transcripts (M-decay, reviewed in Jian and Fan 2022) refers to the degradation of maternal transcripts by maternally provided factors such as ZFP36L2 (inferred from the mouse homolog in Chousal et al. 2018, Sha et al. 2018), BTG4 (inferred from the mouse homolog in Liu et al. 2016, Yu et al. 2016, Pasternak et al. 2016, Zhao et al. 2020), and AGO2 (inferred from the mouse homolog in Zhang et al. 2020). ZFP36L2 acting before fertilization and BTG4 acting after fertilization recruit the CCR4-NOT deadenylation complex to the mRNA to initiate degradation. AGO2 is primed with endogenous small interfering RNAs (endosiRNAs) produced from double-stranded RNAs that originate from specific loci. The resulting AGO2:endosiRNA complexes bind and hydrolyze complementary maternal mRNAs. Similar patterns of mRNA decay are observed in human and mouse zygotes (Sha et al. 2020).

Literature Reactome attaches

Dynamics and clinical relevance of maternal mRNA clearance during the oocyte-to-embryo transition in humansNat Commun, 2020, vol. 11, p. 4917PubMed 33004802
CNOT6L couples the selective degradation of maternal transcripts to meiotic cell cycle progression in mouse oocyteEMBO J, 2018, vol. 37PubMed 30478191
Chromatin Modification and Global Transcriptional Silencing in the Oocyte Mediated by the mRNA Decay Activator ZFP36L2Dev Cell, 2018, vol. 44, p. 392-402.e7PubMed 29408237
BTG4 is a meiotic cell cycle-coupled maternal-zygotic-transition licensing factor in oocytesNat Struct Mol Biol, 2016, vol. 23, p. 387-94PubMed 27065194
The BTG4 and CAF1 complex prevents the spontaneous activation of eggs by deadenylating maternal mRNAsOpen Biol, 2016, vol. 6PubMed 27605379
BTG4 is a key regulator for maternal mRNA clearance during mouse early embryogenesisJ Mol Cell Biol, 2016, vol. 8, p. 366-8PubMed 27190313
Five questions toward mRNA degradation in oocytes and preimplantation embryos: when, who, to whom, how, and why?†Biol Reprod, 2022, vol. 107, p. 62-75PubMed 35098307
Argonaute 2 is a key regulator of maternal mRNA degradation in mouse early embryosCell Death Discov, 2020, vol. 6, p. 133PubMed 33298889
PABPN1L mediates cytoplasmic mRNA decay as a placeholder during the maternal-to-zygotic transitionEMBO Rep, 2020, vol. 21, p. e49956PubMed 32558204

Reactome ContentService, this pathway's record · Reactome v97 · read 2026-10-01 ET · Reactome pathway browser"M-decay: degradation of maternal mRNAs by maternally stored factors". Reactome, release 97, https://reactome.org/PathwayBrowser/#/R-HSA-9820841 with StableID: R-HSA-9820841.1 (accessed 2026-10-01 ET). Reactome version 97 (CC0).

Reading this pathway's record from Reactome (the pathway record).Still reading. A first read of a pathway can take a while; this page waits up to 35 seconds for it, and its scripts then bring in the panel, or a line saying what did not arrive.

02The genes

Genes Reactome places in this human pathway

The mapping files place 33 genes in this human pathway; showing 1 to 33, in pages of 100, sorted by symbol for reading. The order carries no ranking.

Genes Reactome places in this human pathway, page 1 of 1
Gene	Authority id	Mapping file id	Evidence codes
GeneAGO2	AuthorityHGNC:3263	Mapping file id27161 NCBI file	EvidenceIEA
GeneBTG4	AuthorityHGNC:13862	Mapping file id54766 NCBI file	EvidenceIEA
GeneCNOT1	AuthorityHGNC:7877	Mapping file id23019 NCBI file	EvidenceIEA
GeneCNOT10	AuthorityHGNC:23817	Mapping file id25904 NCBI file	EvidenceIEA
GeneCNOT11	AuthorityHGNC:25217	Mapping file id55571 NCBI file	EvidenceIEA
GeneCNOT12	AuthorityHGNC:19081	Mapping file id85456 NCBI file	EvidenceIEA
GeneCNOT2	AuthorityHGNC:7878	Mapping file id4848 NCBI file	EvidenceIEA
GeneCNOT3	AuthorityHGNC:7879	Mapping file id4849 NCBI file	EvidenceIEA
GeneCNOT4	AuthorityHGNC:7880	Mapping file id4850 NCBI file	EvidenceIEA
GeneCNOT6	AuthorityHGNC:14099	Mapping file id57472 NCBI file	EvidenceIEA
GeneCNOT6L	AuthorityHGNC:18042	Mapping file id246175 NCBI file	EvidenceIEA
GeneCNOT7	AuthorityHGNC:14101	Mapping file id29883 NCBI file	EvidenceIEA
GeneCNOT8	AuthorityHGNC:9207	Mapping file id9337 NCBI file	EvidenceIEA
GeneCNOT9	AuthorityHGNC:10445	Mapping file id9125 NCBI file	EvidenceIEA
GeneDICER1	AuthorityHGNC:17098	Mapping file id23405 NCBI file	EvidenceIEA
GeneEIF4A1	AuthorityHGNC:3282	Mapping file id1973 NCBI file	EvidenceIEA
GeneEIF4A2	AuthorityHGNC:3284	Mapping file id1974 NCBI file	EvidenceIEA
GeneEIF4A3	AuthorityHGNC:18683	Mapping file id9775 NCBI file	EvidenceIEA
GeneEIF4B	AuthorityHGNC:3285	Mapping file id1975 NCBI file	EvidenceIEA
GeneEIF4E	AuthorityHGNC:3287	Mapping file id1977 NCBI file	EvidenceIEA
GeneEIF4G1	AuthorityHGNC:3296	Mapping file id1981 NCBI file	EvidenceIEA
GeneELOC	AuthorityHGNC:11617	Mapping file idENSG00000154582 Ensembl file	EvidenceIEA
GeneFGF8	AuthorityHGNC:3686	Mapping file idENSG00000107831 Ensembl file	EvidenceIEA
GeneNOBOX	AuthorityHGNC:22448	Mapping file idENSG00000106410 Ensembl file	EvidenceIEA
GenePABPC1	AuthorityHGNC:8554	Mapping file id26986 NCBI file	EvidenceIEA
GenePABPN1L	AuthorityHGNC:37237	Mapping file id390748 NCBI file	EvidenceIEA
GenePADI6	AuthorityHGNC:20449	Mapping file idENSG00000276747 Ensembl file	EvidenceIEA
GenePAIP1	AuthorityHGNC:16945	Mapping file id10605 NCBI file	EvidenceIEA
GenePAIP2	AuthorityHGNC:17970	Mapping file idENSG00000120727 Ensembl file	EvidenceIEA
GenePOLR2D	AuthorityHGNC:9191	Mapping file idENSG00000144231 Ensembl file	EvidenceIEA
GeneRPS2	AuthorityHGNC:10404	Mapping file idENSG00000140988 Ensembl file	EvidenceIEA
GeneZFP36L2	AuthorityHGNC:1108	Mapping file id678 NCBI file	EvidenceIEA
GeneZP2	AuthorityHGNC:13188	Mapping file idENSG00000103310 Ensembl file	EvidenceIEA

Evidence codes on this page: IEA, as the mapping file writes them; a row carrying two was written twice by the file, once under each. The mapping file id says which file placed the gene: an NCBI Gene id from NCBI2Reactome_All_Levels.txt, an Ensembl gene id from Ensembl2Reactome_All_Levels.txt. The two files can disagree about a code, so a row's codes are the one file's view. Measured by this site's build over this release on 2026-09-09: of the 138,908 human pathway-gene pairs both files place, 207 (0.149 per cent, over 47 genes) carry TAS in the Ensembl file where the NCBI rows carry IEA alone.

Reactome mapping files, the human rows for this pathway · Reactome release 97 · read 2026-09-09 · Reactome downloads"NCBI2Reactome_All_Levels.txt" and "Ensembl2Reactome_All_Levels.txt", Reactome, release 97, https://reactome.org/download-data/ (date of access 2026-09-09). Data CC0; attribution encouraged.

03The hierarchy

Parents and children in this release's hierarchy

Parents

Maternal to zygotic transition (MZT)R-HSA-9816359128 genes

Children

None: no pathway of this release's list names this one as a parent.

Reactome's hierarchy is a graph rather than a tree: a pathway can sit under more than one parent, and the gene counts are each pathway's own placements at every level under it, so a parent's count is not the sum of its children's.

Reactome, the human pathway list and hierarchy relationship file · Reactome release 97 · read 2026-09-09 · Reactome downloads"ReactomePathways.txt" and "ReactomePathwaysRelation.txt", Reactome, release 97, https://reactome.org/download-data/ (date of access 2026-09-09). Data CC0; attribution encouraged.