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Expr14968
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Both ife-1 and ife-3 were robustly expressed in the gonad throughout development, but expression and localization patterns were distinct. Both IFE-1 and IFE-3 localized to perinuclear germ granules but were also soluble in the cytoplasm of germ cells in the distal gonad (mitotic to early pachytene region). Our previous study found IFE-1 in embryonic P granules (Amiri et al., 2001). Intriguingly, we observed separate perinuclear localization of IFE-1 and IFE-3 in a strain expressing both IFE fusions. IFE-1 granules were larger than IFE-3 granules and more numerous. Another striking difference between IFE-1 and IFE-3 was seen in the rachis (gonad core), where IFE-3 associated with lattice-like structures. IFE-1 did not form similar structures. In the distal gonad, the soluble fractions of IFE-1 and IFE-3 were overlapping, unlike their respective granules.In spermatocytes and oocytes, IFE-1 and IFE-3 localization patterns became even more divergent. Using nuclear morphology to stage spermatocytes, we observed that IFE-1 was upregulated in 1o spermatocytes, where it formed perinuclear granules, then became largely soluble in 2o spermatocytes. After spermatid budding, IFE-1 was deposited into residual bodies. Conversely, IFE-3 was soluble throughout spermatogenesis and was diminished early in 2o spermatocytes. In oocytes IFE-3 was strongly expressed and fully soluble, whereas IFE-1 formed granules. Our observations suggest that each eIF4E isoform forms distinct granules in early germ cells, but then each becomes soluble in the respective gametes where they predominate; IFE-1 in spermatocytes and IFE-3 in oocytes. |
IFE-3 localizes to perinuclear granules adjacent to IFE-1:PGL-1 granulesWe confirmed IFE-1 residence in P granules of distal germ cells by co-localization with a PGL-1::GFP CRISPR fusion. We observed a high degree of overlap for IFE-1 and PGL-1 in germ cells. IFE-1 expression was notably upregulated in 1o spermatocytes from L4 hermaphrodites where it was enriched in PGL-1 granules. Importantly, IFE-1 left PGL-1 granules and became soluble when PGL-1 disappeared from 2o spermatocytes. |
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Expr14384
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We found that in the male germline SET-17::GFP was expressed predominantly in primary spermatocytes. SET-17::GFP was first detectable at the initiation of spermatocyte differentiation in L4 and adult males. The SET-17::GFP level increased with the stage of spermatocyte progression and peaked in late-stage primary spermatocytes. |
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Expr11853
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VBH-1 antibody staining showed the same localization in oocytes and embryos as observed with the VBH-1:GFP fusion (Expr11852). VBH-1 was observed throughout both the hermaphrodite and male gonad. In the male gonad, VBH-1 was observed in primary and secondary spermatocytes but not detected in mature sperm. |
VBH-1 was expressed in P granules throughout the gonad, and also diffusely in the cytoplasm. VBH-1, however, was not detected in the P-body-like particles. |
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Expr15151
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GFP::SPE-15 accumulated mainly in the nucleus of primary spermatocytes, and was released later into the cytosol, probably due to nuclear envelope breakdown. After the onset of meiosis II, GFP::SPE-15 was recruited to the cell cortex and moved from the spermatid pole to the spermatid-residual body (RB) boundary during RB expansion. |
