The G protein coupled receptor 3 is involved in cAMP and cGMP signaling and maintenance of meiotic arrest in porcine oocytes.
The arrest of meiotic prophase in mammalian oocytes within fully grown follicles is dependent on cyclic adenosine monophosphate (cAMP) regulation. A large part of cAMP is produced by the Gs-linked G-protein-coupled receptor (GPR) pathway. In the present study, we examined whether GPR3 is involved in the maintenance of meiotic arrest in porcine oocytes. Expression and distribution of GPR3 were examined by western blot and immunofluorescence microscopy, respectively. The results showed that GPR3 was expressed at various stages during porcine oocyte maturation. At the germinal vesicle (GV) stage, GPR3 displayed a maximal expression level, and its expression remained stable from pro-metaphase I (MI) to metaphase II (MII). Immunofluorescence staining showed that GPR3 was mainly distributed at the nuclear envelope during the GV stage and localized to the plasma membrane at pro-MI, MI and MII stages. RNA interference (RNAi) was used to knock down the GPR3 expression within oocytes. Injection of small interfering double-stranded RNA (siRNA) targeting GPR3 stimulated meiotic resumption of oocytes. On the other hand, overexpression of GPR3 inhibited meiotic maturation of porcine oocytes, which was caused by increase of cGMP and cAMP levels and inhibition of cyclin B accumulation. Furthermore, incubation of porcine oocytes with the GPR3 ligand sphingosylphosphorylcholine (SPC) inhibited oocyte maturation. We propose that GPR3 is required for maintenance of meiotic arrest in porcine oocytes through pathways involved in the regulation of cAMP and cGMP.
College of Life Science, Northeast Agricultural University of China, Harbin, China.
Cai-Rong
CR
Yang
Yanchang
Y
Wei
Shu-Tao
ST
Qi
Lei
L
Chen
Qing-Hua
QH
Zhang
Jun-Yu
JY
Ma
Yi-Bo
YB
Luo
Ya-Peng
YP
Wang
Yi
Y
Hou
Heide
H
Schatten
Zhong-Hua
ZH
Liu
Qing-Yuan
QY
Sun
D000818:Animals; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism*; D019926:Cyclin B / Q000378:metabolism; D005260:Female; D008540:Meiosis; D049469:Meiotic Prophase I; D008677:Metaphase; D008856:Microscopy, Fluorescence; D009685:Nuclear Envelope / Q000378:metabolism; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010767:Phosphorylcholine / Q000031:analogs & derivatives / Q000494:pharmacology; D034622:RNA Interference; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013110:Sphingosine / Q000031:analogs & derivatives / Q000494:pharmacology; D013552:Swine; D013997:Time Factors
D019926:Cyclin B; D043562:Receptors, G-Protein-Coupled; C005356:sphingosine phosphorylcholine; D010767:Phosphorylcholine; D000242:Cyclic AMP; D006152:Cyclic GMP; D013110:Sphingosine