title: Subcellular Characterization of Porcine Oocytes with Different Glucose-6-phosphate Dehydrogenase Activities.
abstract: The in vitro maturation (IVM) efficiency of porcine embryos is still low because of poor oocyte quality. Although brilliant cresyl blue positive (BCB+) oocytes with low glucose-6-phosphate dehydrogenase (G6PDH) activity have shown superior quality than BCB negative (-) oocytes with high G6PDH activity, the use of a BCB staining test before IVM is still controversial. This study aimed to shed more light on the subcellular characteristics of porcine oocytes after selection using BCB staining. We assessed germinal vesicle chromatin configuration, cortical granule (CG) migration, mitochondrial distribution, the levels of acetylated lysine 9 of histone H3 (AcH3K9) and nuclear apoptosis features to investigate the correlation between G6PDH activity and these developmentally related features. A pattern of chromatin surrounding the nucleoli was seen in 53.0% of BCB+ oocytes and 77.6% of BCB+ oocytes showed peripherally distributed CGs. After IVM, 48.7% of BCB+ oocytes had a diffused mitochondrial distribution pattern. However, there were no significant differences in the levels of AcH3K9 in the nuclei of blastocysts derived from BCB+ and BCB- oocytes; at the same time, we observed a similar incidence of apoptosis in the BCB+ and control groups. Although this study indicated that G6PDH activity in porcine oocytes was correlated with several subcellular characteristics such as germinal vesicle chromatin configuration, CG migration and mitochondrial distribution, other features such as AcH3K9 level and nuclear apoptotic features were not associated with G6PDH activity and did not validate the BCB staining test. In using this test for selecting porcine oocytes, subcellular characteristics such as the AcH3K9 level and apoptotic nuclear features should also be considered. Adding histone deacetylase inhibitors or apoptosis inhibitors into the culture medium used might improve the efficiency of IVM of BCB+ oocytes.
authors.affiliation: Heilongjiang Academy of Agricultural Sciences Postdoctoral Programme, Northeast Forestry University Postdoctoral Programme, Harbin 150086, China ; Institute of Animal Husbandry Research, Heilongjiang Academy of Agricultural Sciences, Harbin 150086, China .
authors.forename: Bo
authors.initials: B
authors.lastname: Fu
authors.affiliation: College of Animal Science, Northeast Agriculture University, Harbin 150030, China .
authors.forename: Liang
authors.initials: L
authors.lastname: Ren
authors.affiliation: Institute of Animal Husbandry Research, Heilongjiang Academy of Agricultural Sciences, Harbin 150086, China . ; College of Animal Science, Northeast Agriculture University, Harbin 150030, China .
authors.forename: Di
authors.initials: D
authors.lastname: Liu
authors.affiliation: Heilongjiang Academy of Agricultural Sciences Postdoctoral Programme, Northeast Forestry University Postdoctoral Programme, Harbin 150086, China.
authors.forename: Jian-Zhang
authors.initials: JZ
authors.lastname: Ma
authors.affiliation: Heilongjiang Academy of Agricultural Sciences Postdoctoral Programme, Northeast Forestry University Postdoctoral Programme, Harbin 150086, China.
authors.forename: Tie-Zhu
authors.initials: TZ
authors.lastname: An
authors.affiliation: College of Animal Science, Northeast Agriculture University, Harbin 150030, China .
authors.forename: Xiu-Qin
authors.initials: XQ
authors.lastname: Yang
authors.affiliation: Institute of Animal Husbandry Research, Heilongjiang Academy of Agricultural Sciences, Harbin 150086, China .
authors.forename: Hong
authors.initials: H
authors.lastname: Ma
authors.affiliation: Institute of Animal Husbandry Research, Heilongjiang Academy of Agricultural Sciences, Harbin 150086, China .
authors.forename: Dong-Jie
authors.initials: DJ
authors.lastname: Zhang
authors.affiliation: Institute of Animal Husbandry Research, Heilongjiang Academy of Agricultural Sciences, Harbin 150086, China .
authors.forename: Zhen-Hua
authors.initials: ZH
authors.lastname: Guo
authors.affiliation: College of Animal Science, Northeast Agriculture University, Harbin 150030, China .
authors.forename: Yun-Yun
authors.initials: YY
authors.lastname: Guo
authors.affiliation: College of Animal Science, Northeast Agriculture University, Harbin 150030, China .
authors.forename: Meng
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Modern Education Technology and Information Center, Heilongjiang University of Chinese Medicine, Harbin 150040, China .
authors.forename: Jing
authors.initials: J
authors.lastname: Bai
keywords: Brilliant Cresyl Blue; Embryonic Development; Porcine Oocytes; Subcellular Characteristics