Vitrification procedure decreases inositol 1, 4, 5‐trisphophate receptor expression, resulting in low fertility of pig oocytes. (8th April 2013)

• Record Type: Journal Article
• Authors: Hirose, Masahiko; Kamoshita, Maki; Fujiwara, Katsuyoshi; Kato, Tsubasa; Nakamura, Ayaka; Wojcikiewicz, Richard J. H.; Parys, Jan B.; Ito, Junya; Kashiwazaki, Naomi
• Is Part Of: Animal science journal. Volume 84:Number 10(2013:Oct.)
• Page Start: 693
• Page End: 701
• Publication Date: 2013-04-08
• Subjects: Animal culture -- Periodicals; Livestock -- Periodicals; 636
• DOI: 10.1111/asj.12061
• Languages: English
• ISSNs: 1344-3941

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>Although cryopreservation of mammalian oocytes is an important technology, it is well known that unfertilized oocytes, especially in pigs, are highly sensitive to low temperature and that cryopreserved oocytes show low fertility and developmental ability. The aim of the present study was to clarify why porcine <italic>in vitro</italic> matured (IVM) oocytes at the metaphase II (MII) stage showed low fertility and developmental ability after vitrification. <italic>In vitro</italic> matured cumulus oocyte complexes (COCs) were vitrified with Cryotop and then evaluated for fertility through <italic>in vitro</italic> fertilization (IVF). Although sperm‐penetrated oocytes were observed to some extent (30–40%), the rate of pronuclear formation was low (9%) and none of them progressed to the two‐cell stage. The results suggest that activation ability of cryopreserved oocytes was decreased by vitrification. We examined the localization and expression level of the type 1 inositol 1, 4, 5 trisphosphate receptor (IP<sub>3</sub>R1), the channel responsible for Ca<sup>2+</sup> release during IVF in porcine oocytes. Localization of IP<sub>3</sub>R1 close to the plasma membrane and total expression level of IP<sub>3</sub>R1 protein were both decreased by vitrification. In conclusion, our present study indicates that vitrified‐warmed porcine COCs showed a high survival rate but low fertility after IVF. This low fertility seems to be due to the decrease in IP<sub>3</sub>R1 by the vitrification procedure.</p> </abstract>