The Role of Ca2 + in Maturation and Reprogramming of Bovine Oocytes: A System Study of Low-Calcium Model

Abstract

[Ca2+]i is essential for mammalian oocyte maturation and early embryonic development, as those processes are Ca2+ dependent. In the present study, we investigated the effect of [Ca2+]i on in vitro maturation and reprogramming of oocytes in a lower calcium model of oocyte at metaphase II (MII) stage, which was established by adding cell-permeant Ca2+ chelator BAPTA-AM to the maturation medium. Results showed that the extrusion of the first polar body (PB1) was delayed, and oocyte cytoplasmic maturation, including mitochondrial and endoplasmic reticulum distribution, was impaired in lower calcium model. The low-calcium-model oocytes presented a poor developmental phenotype of somatic cell nuclear transfer (SCNT) embryos at the beginning of activation of zygotic genome. At the same time, oxidative stress and apoptosis were observed in the low-calcium-model oocytes; subsequently, an RNA-seq analysis of the lower-calcium-model oocytes screened 24 genes responsible for the poor oocyte reprogramming, and six genes (ID1, SOX2, DPPA3, ASF1A, MSL3, and KDM6B) were identified by quantitative PCR. Analyzing the expression of these genes is helpful to elucidate the mechanisms of [Ca2+]i regulating oocyte reprogramming. The most significant difference gene in this enriched item was ID1. Our results showed that the low calcium might give rise to oxidative stress and apoptosis, resulting in impaired maturation of bovine oocytes and possibly affecting subsequent reprogramming ability through the reduction of ID1.

Preimplantation Developmental Competence of Bovine and Porcine Oocytes Activated by Zinc Chelation

“…Thus, in this species, calcium rise during oocyte activation seems important for blastocyst development and early cell differentiation during the preimplantation period. This agrees with a recent study that also suggests a crucial role of calcium in the reprogramming of bovine oocytes [ 35 ]. On the contrary, porcine embryos developmental rates were higher and no differences in quality and pluripotent markers were observed.…”

Chicken pituitary transcriptomic responses to acute heat stress

“…The apoptosis inhibitors, HERPUD, DNAJB5, and JMJD6, have already been described. Additional apoptosis inhibitors include: BAG3 [ 39 ], HSP90AA1 [ 40 ], HSPA5 [ 41 ], ID1 [ 42 ] PPP1R10 [ 43 ] and SENP1 [ 44 ], while ZBTB16 [ 38 ] activates apoptosis. Autophagy is a lysosomal based degradation pathway with specific targets that are recycled for cellular maintenance.…”

Effects of DON on Mitochondrial Function, Endoplasmic Reticulum Stress, and Endoplasmic Reticulum Mitochondria Contact Sites in the Jejunum of Piglets

“…ERMCSs are known to function as the multifunctional subcellular structures for the signaling hubs between mitochondria and ER. , Regarding the mitochondria-related results, we observed that DON increased mitochondrial calcium content and caused mitochondrial dysfunction. Given that the ER serves as the primary intracellular calcium storage organelle, we hypothesized that the excessive increase of ERMCSs may lead to a homeostasis imbalance between ER and mitochondria, resulting in a large influx of calcium ions from ER to mitochondria . This, in turn, may lead to mitochondrial calcium ion overload and dysfunction.…”

“…Given that the ER serves as the primary intracellular calcium storage organelle, we hypothesized that the excessive increase of ERMCSs may lead to a homeostasis imbalance between ER and mitochondria, resulting in a large influx of calcium ions from ER to mitochondria. 48 This, in turn, may lead to mitochondrial calcium ion overload and dysfunction. Meanwhile, the increased interaction strength of IP3R and VDAC1, known as the calcium channel between mitochondria and ER, further supported our point of view.…”