Calreticulin is required for development of the cumulus oocyte complex and female fertility

Abstract

Calnexin (CANX) and calreticulin (CALR) chaperones mediate nascent glycoprotein folding in the endoplasmic reticulum. Here we report that these chaperones have distinct roles in male and female fertility. Canx null mice are growth retarded but fertile. Calr null mice die during embryonic development, rendering indeterminate any effect on reproduction. Therefore, we conditionally ablated Calr in male and female germ cells using Stra8 (mcKO) and Zp3 (fcKO) promoter-driven Cre recombinase, respectively. Calr mcKO male mice were fertile, but fcKO female mice were sterile despite normal mating behavior. Strikingly, we found that Calr fcKO female mice had impaired folliculogenesis and decreased ovulatory rates due to defective proliferation of cuboidal granulosa cells. Oocyte-derived, TGF-beta family proteins play a major role in follicular development and molecular analysis revealed that the normal processing of GDF9 and BMP15 was defective in Calr fcKO oocytes. These findings highlight the importance of CALR in female reproduction and demonstrate that compromised CALR function leads to ovarian insufficiency and female infertility.

Calreticulin Regulates Neointima Formation and Collagen Deposition following Carotid Artery Ligation

“…Mice with the calr gene flanked by LoxP sites at exons 4 and 7 were generated as described [35]. PCR was performed on DNA from wild type and CRT floxed mice using primers specifically designed to detect the presence of LoxP sites.…”

“…CRT floxed mice on the B6D2F1 background were generated by Ikawa et al [35]. Ten to 14-week-old CRT floxed mice were maintained at constant humidity (60 ± 5%), temperature (24 ± 1°C), and light cycle (6:00 A.M. to 6:00 P.M.).…”

Calnexin is necessary for T cell transmigration into the central nervous system

“…Calnexin-deficient mice were generated as previously described (18). To inactivate the (27), were crossed with Lck-Cre + transgenic mice (C57BL/6), which express the Cre recombinase under the control of the T cell-specific Lck promoter (The Jackson Laboratory, B6.Cg-Tg[Lck-cre]548Jxm/J]. Presence of the flox and Cre recombinase alleles was confirmed by PCR analysis using the following set of DNA primers: 5′-GCTCTGGATGCCTTGGGATTTGATTTCC-3′; 5′-GGATTTAGTGGATATCCCCAG-TATGAGC-3′; Cre-F2, 5′-GCCAGCTAAACATGCTTCATC-3′; Cre-B2, 5′-ATTGCCCCTGTTTCAC-TATCC-3′.…”

The Mg2+ transporter CNNM4 regulates sperm Ca2+ homeostasis and is essential for reproduction

“…Specific disruption of Cnnm4 in male germ cells was achieved using the following 3-step procedure: (1) Cnnm4 +/Δ ;Stra8-Cre mice were generated by mating Cnnm4 +/Δ mice with transgenic mice expressing Cre recombinase under the control of the germ-cell-specific Stra8 promoter (Tokuhiro et al, 2015). (2) To generate the allele Cnnm4 flox , in which exons 2-5 of Cnnm4 can be deleted in the presence of Cre recombinase, Cnnm4 −/− mice were mated with transgenic mice expressing optimized Flp recombinase (Flpo) under the control of a ubiquitous CAG promoter produced as explained in the next paragraph.…”