| Year | Citation (short) | Publication type | Main meg-2-related findings (localization/function/phenotype/interactions) | Key quantitative data/statistics | URL/DOI | Notes on evidence strength (meg-2 specific vs meg-1/2 combined) |
|---|---|---|---|---|---|---|
| 2008 | Leacock & Reinke, *Genetics* | Primary research | Verified target identity in *C. elegans*: MEG-2 corresponds to the embryo-specific maternal-effect germ cell defective protein encoded by **meg-2/K02B9.2**. GFP::MEG-2 localizes to embryonic P granules in the P lineage (P2/P3/P4) and Z2/Z3; MEG-2 is functionally redundant with MEG-1, and increased MEG-2 dosage can partially compensate for loss of MEG-1. P-granule association is transient and embryo-restricted. | MEG-1/MEG-2 localization starts at ~4–8-cell stage and fades by ~100-cell stage when Z2/Z3 are born; **nos-2** staining in late P4/Z2/Z3 was seen in **~52% vs ~55%** of meg-1 vs wild type embryos (MEG-1-focused control context); meg-1 sterility is high (>90% at restrictive temperature) and GFP::MEG-2 partially rescues meg-1 sterility at 25°C (pqac-00000006, pqac-00000011) | https://doi.org/10.1534/genetics.107.080218 | Strongest direct source for MEG-2 identity/localization; some phenotype data are meg-1-centered, with MEG-2 mainly inferred through redundancy and rescue (pqac-00000006, pqac-00000011) |
| 2010 | Updike & Strome, *J. Andrology* | Review | Reviews P-granule assembly/function in *C. elegans* and places MEG proteins within the embryonic germ plasm/P-granule pathway. Useful for pathway context and expert interpretation that P granules regulate post-transcriptional gene control in the germ line. | No meg-2-specific quantitative statistics in retrieved context. | https://doi.org/10.2164/jandrol.109.008292 | Contextual review; not meg-2-specific and not primary evidence in the retrieved excerpts. |
| 2011 | Kapelle & Reinke, *genesis* | Primary research | MEG-1 and MEG-2 are closely related, transient P-granule proteins acting during early embryogenesis but affecting later germ-cell proliferation/survival. Loss of **meg-2** enhances sterile phenotypes, supporting redundancy with **meg-1**. Study highlights genetic interactions in the MEG-1/2 module with nanos-family genes, especially functional opposition/synergy involving **nos-2** and **nos-3**. | Expression window emphasized for MEG proteins: **4-cell to 28-cell stages**; no direct meg-2-only penetrance values in retrieved excerpt. Reported directionality: **nos-3 loss suppresses** meg-1 sterility, **nos-2 loss enhances** meg-1 sterility and abolishes proliferation beyond Z2/Z3 (pqac-00000007, pqac-00000010) | https://doi.org/10.1002/dvg.20726 | Moderate evidence for MEG-2 because it is discussed mainly as a redundant paralog of MEG-1; strongest for genetic interaction logic, weaker for meg-2-specific mechanistic detail (pqac-00000007, pqac-00000010) |
| 2014 | Wang et al., *eLife* | Primary research | Positions MEG proteins as intrinsically disordered, serine-rich regulators of embryonic RNA-granule dynamics. Although direct biochemical targeting was shown for MEG-1/3, the paper infers that **MEG-2**, like MEG-1, likely contributes to granule disassembly because of its acidic character. Crucially, fertility defects in MEG mutants can be uncoupled from visible P-granule assembly defects, implying a broader germ-plasm activity. | Predicted unphosphorylated pI: **MEG-1 6.63; MEG-2 6.04; MEG-3 9.74; MEG-4 9.33**. Sterility examples: **meg-1 ~4% sterile; meg-3 meg-4 ~30% sterile; meg-1 meg-3 meg-4 100% sterile**. **meg-1 meg-2** embryos still assemble embryonic P granules yet share fully penetrant Meg sterility with **meg-1 meg-3 meg-4** (pqac-00000004, pqac-00000008) | https://doi.org/10.7554/eLife.04591 | Strong for MEG network logic and phase-separation model; indirect for MEG-2 molecular mechanism because phosphorylation was demonstrated for MEG-1/3, not directly for MEG-2 in retrieved text (pqac-00000004, pqac-00000008) |
| 2019 | Marnik & Updike, *Traffic* | Review | Reviews membraneless organelles/P granules in *C. elegans* and the role of intrinsically disordered proteins in phase separation. Useful for expert framing of MEG proteins as scaffold-like regulators of condensate behavior. | No meg-2-specific quantitative statistics in retrieved context. | https://doi.org/10.1111/tra.12644 | Broad condensate review; useful conceptual context only, not direct meg-2 evidence. |
| 2020 | Lee et al., *eLife* | Primary research | Demonstrates that P granules recruit mRNAs via condensation with intrinsically disordered **MEG-3**, establishing a mechanistic framework for how MEG-family proteins can organize RNA-rich condensates. Not meg-2-specific, but highly relevant for interpreting MEG-2 as an IDP-associated germ-plasm factor in mRNA handling. | ~**500 mRNAs** bound/recruited in vivo by MEG-3-based mechanism; localization to P granules enriches maternal RNAs in the germ lineage (from abstract/snippet context). | https://doi.org/10.7554/eLife.52896 | Indirect evidence only for meg-2; included as mechanistic context on MEG-family/P-granule biology rather than as a meg-2 study. |
| 2021 | Oyewale thesis snippet | Thesis / supporting mention | Low-weight supporting mention that **meg-1 and meg-2 are expressed in the embryonic P lineage and degraded concomitant with PGC birth**, consistent with their transient embryonic role. | No primary quantitative meg-2 data extracted in retrieved snippet. | https://doi.org/10.25673/82467 | Very low evidence weight; secondary/thesis mention only, included solely as supportive context. |
| 2022 | Cassani & Seydoux, *Development* | Primary research | Major update: MEG-1/2 are redefined as components of **germline P-bodies**, distinct from canonical P granules. In P4, MEG-1/2 maintain P-body factors (**CGH-1/DDX6**, **EDC-3**), promote deadenylation/turnover of maternal mRNAs, support translational activation of germline determinants (**nos-2, Y51F10.2, xnd-1**), and are required for correct germline founder-cell fate. MEG-1/2 genetically/functionally interact with **POS-1**, **MEG-3/4**, and factors such as **GLD-2/GLD-3**. | In **meg-1 meg-2** embryos: RNA-seq found **550 upregulated** and **230 downregulated** mRNAs; **223/550 (40%)** upregulated genes overlap deadenylated POS-1 targets (**Fisher’s exact test P=0.0002**). **hlh-1** ectopic expression in **21/23** embryos vs **0/21** WT; robust **xnd-1** activation fails in **16/24** embryos; extra P-granule-positive cells in **50%** of bean-to-comma embryos and **100%** of non-fed L1s; **100% sterile**. Quantification sample sizes included: CGH-1 WT **n=10** vs meg-1/2 **n=12**; EDC-3 WT **n=12** vs meg-1/2 **n=9**; POS-1 WT **n=19** vs meg-1/2 **n=8**; poly-A/SL1 WT **n=26** vs meg-1/2 **n=13** (pqac-00000000, pqac-00000001, pqac-00000002, pqac-00000003, pqac-00000005, pqac-00000009, pqac-00000012) | https://doi.org/10.1242/dev.200920 | Strongest modern functional source, but almost all key results are for **MEG-1/2 combined loss** rather than MEG-2 alone. Still highly relevant because MEG-2 is part of the obligate functional pair in embryo germline P-bodies (pqac-00000000, pqac-00000001, pqac-00000002, pqac-00000003, pqac-00000005, pqac-00000009, pqac-00000012) |
| 2022 | Phillips & Updike, *Genetics* | Review | Authoritative review summarizing germ granules and sub-granules in *C. elegans* germline gene regulation. Supports the current view that distinct condensates partition functions such as mRNA regulation, small-RNA pathways, and inheritance. Useful for expert interpretation of MEG-1/2 findings within broader germ-granule biology. | No meg-2-specific quantitative statistics in retrieved context. | https://doi.org/10.1093/genetics/iyab195 | High-value expert review for synthesis, but not direct evidence for meg-2 alone. |


*Table: This table summarizes the main primary and review sources relevant to C. elegans meg-2 (UniProt Q21127/K02B9.2), emphasizing where evidence is directly about MEG-2 versus inferred from combined MEG-1/2 biology. It is useful for distinguishing strong gene-specific findings from broader germ-granule context.*