CGC Bibliography Paper 4940

An isoform of eIF4E is a component of germ granules and is required for spermatogenesis in C. elegans.

Amiri A, Keiper BD, Kawasaki I, Fan Y, Kohara Y, Rhoads RE, Strome S

Medline:

11641215

Citation:

Development 128: 3899-3912 2001

Type:

ARTICLE

Genes:

fem-2 fem-3 glp-4 ife-1 ife-2 ife-3 ife-4 ife-5 pgl-1 rde-1 rpp-1

Abstract:

Control of gene expression at the translational level is crucial for many developmental processes. The mRNA cap-binding protein, eIF4E, is a key player in regulation of translation initiation; appropriate levels of eIF4E are essential for normal cell-cycle regulation and tissue differentiation. The observation that eIF4E levels are elevated during gametogenesis in several organisms suggests that eIF4E might have a specific role in gamete formation as well. We show that one of the five isoforms of C. elegans eIF4E, IFE-1, is enriched in the germline and is a component of germ granules (P granules). The association of IFE-1 with P granules requires the P-granule protein PGL-1. In vitro PGL-1 interacts directly with IFE-1, but not with the other four isoforms of eIF4E. Analysis of animals depleted of IFE-1 by RNAi shows that IFE-1 is required for spermatogenesis, specifically for efficient progression through the meiotic divisions and for the production of functional sperm, in both hermaphrodites and males. The requirement for IFE-1 is highly sensitive to temperature. IFE-1 is not required for oogenesis, as ife-1(RNAi) hermaphrodites produce viable progeny when normal sperm are supplied. Consistent with a primary role in spermatogenesis, ife-1 m-RNA levels are highest in regions of the gonad undergoing spermatogenesis. Our results suggest that C. elegans spermatogenesis requires either this specific isoform. of eIF4E or an elevated level of