WormMine: ExpressionPattern Expr14968

• Pattern: 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.
• Primary Identifier: Expr14968
• Subcellular Localization: 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.

4 Anatomy Terms

Definition	Name	Synonym	Primary Identifier
a female haploid germ cell.	oocyte	ovum	WBbt:0006797
organ producing either sperm or ova.	gonad		WBbt:0005175
A diploid immature germ cell which forms in the gonad when a spermatogonial stem cell buds off from the rachis to form a single cell that quickly enters metaphase I and divides to form secondary spermatocytes attached to a residual body.	primary spermatocyte		WBbt:0008591
A haploid immature germ cell which forms in the gonad by the division of a diploid primary spermatocyte. It undergoes a second meiotic division to complete meiosis, at which time the daughter cells detach from the residual body to become spermatids.	secondary spermatocyte		WBbt:0008592

1 Genes

WormBase Gene ID	Gene Name	Sequence Name	Organism
WBGene00002059	ife-1	F53A2.6	Caenorhabditis elegans

1 Life Stages

Remark	Definition	Other Name	Public Name	Primary Identifier
	All C. elegans development stages, including embryo, larva and adult stage.		all stages Ce	WBls:0000002