Expr14969

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.

Expr14968

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.