Biological significance of sperm-independent calcium oscillations in immature oocytes of mice

TL;DR

This study explores the role of calcium oscillations in immature mouse oocytes and their connection to ovarian function.

Contribution

The study reveals a potential regulatory role of extramitochondrial citrate synthase in calcium oscillations and ovarian development.

Findings

eCs-KO mice showed slower reduction of Ca2+ oscillations during the juvenile period.

Adult eCs-KO mice had ovaries with follicles containing two oocytes.

eCS may suppress spontaneous Ca2+ oscillations to maintain ovarian functions.

Abstract

Sperm-independent Ca
2+
oscillations are induced in immature oocytes, and presumably contribute to oocyte quality; however, its physiological role remains unclear. We studied the significance of Ca
2+
oscillations in ovarian functions using extramitochondrial citrate synthase (
eCs
)-deficient (KO) female mice. In wild-type mice, the percentage of Ca
2+
oscillation-induced oocytes gradually decreased during their juvenile period, and dropped at the beginning of their adult period, whereas its percentage reduced more slowly in juvenile
eCs
-KO mice. Moreover, ovarian follicles containing two oocytes were frequently observed in ovaries of adult
eCs
-KO female mice. We assume that eCS suppresses spontaneous Ca
2+
oscillations, probably maintaining ovarian functions.

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