Heterozygous Eif4nif1 Stop Gain Mice Replicate the Primary Ovarian Insufficiency Phenotype in Women

Endocrinology. 2025 Jan 18:bqaf014. doi: 10.1210/endocr/bqaf014. Online ahead of print.

Abstract

We created the c.1286C>G stop-gain mutation found in a family with primary ovarian insufficiency (POI) at age 30 years. The Eif4enif1 C57/Bl6 transgenic mouse model contained a floxed exon 10-19 cassette with a conditional knock-in cassette containing the c.1286C>G stop-gain mutation in exon 10. The hybrid offspring of CMV-Cre mice with Eif4enif1WT/flx mice were designated Eif4enif1WT/Δfor simplicity. A subset of female heterozygotes (Eif4enif1WT/Δ) had no litters. In those with litters, the final litter was earlier (5.4±2.6 vs. 10.5±0.7 months; p=0.02). Heterozygous breeding pair (Eif4enif1WT/Δ x Eif4enif1WT/Δ) litter size was 60% of WT litter size (3.9±2.0 vs. 6.5±3.0 pups/litter; p<0.001). The genotypes were 35% Eif4enif1WT/flxand 65% Eif4enif1WT/Δ, with no homozygotes. Homozygote embryos did not develop beyond the 4-8 cell stage. The number of follicles in ovaries from Eif4enif1WT/Δ mice was lower starting at the primordial (499±290 vs. 1445±381) and primary follicle stage (1069±346 vs. 1450±193) on day 10 (p<0.05). The preantral follicle number was lower starting on day 21 (213±86 vs. 522±227; p<0.01). Examination of ribosome protected mRNAs (RPR) demonstrated altered mRNA expression. The Eif4enif1 stop-gain mice replicate the POI phenotype in women based on an earlier end to reproduction due to oocyte loss. The unique mouse model provides a platform to study regulation of protein translation across oocyte and embryo development in mammals.