title: Recombinant Human Bone Morphogenetic Protein 6 Enhances Oocyte Reprogramming Potential and Subsequent Development of the Cloned Yak Embryos.
abstract: This study investigated the effects of bone morphogenetic protein 6 (BMP6) supplementation in the medium during in vitro maturation (IVM) on the developmental potential of oocytes and in the subsequent development of cloned yak embryos. Cumulus-oocyte complexes (COCs) were aspirated from the antral follicles of yak ovaries and cultured with different concentrations of recombinant human BMP6 in oocyte maturation medium. Following maturation, the metaphase II (MII) oocytes were used for somatic cell nuclear transfer (SCNT), and these were cultured in vitro. The development of blastocysts and cell numbers were detected on day 8. The apoptosis and histone modifications of yak cloned blastocysts were evaluated by detecting the expression of relevant genes and proteins (Bax, Bcl-2, H3K9ac, H3K18ac, and H3K9me3) using relative quantitative RT-PCR or immunofluorescence. The presence of 100 ng/mL BMP6 significantly enhanced the oocyte maturation ratios (66.12 ± 2.04% vs. 73.11 ± 1.38%), cleavage rates (69.40 ± 1.03% vs. 78.16 ± 0.93%), and blastocyst formation rates (20.63 ± 1.32% vs. 28.16 ± 1.67%) of cloned yak embryos. The total blastocysts (85.24 ± 3.12 vs. 103.36 ± 5.28), inner cell mass (ICM) cell numbers (19.59 ± 2.17 vs. 32.20 ± 2.61), and ratio of ICM to trophectoderm (TE) (22.93 ± 1.43% vs. 31.21 ± 1.62%) were also enhanced (p < 0.05). The ratio of the Bax to the Bcl-2 gene was lowest in the SCNT + BMP6 groups (p < 0.05). The H3K9ac and H3K18ac levels were increased in SCNT + BMP6 groups (p < 0.05), whereas the H3K9me3 level was decreased; the differences in blastocysts were not significant (p > 0.05). These study results demonstrate that addition of oocyte maturation medium with recombinant BMP6 enhances yak oocyte developmental potential and the subsequent developmental competence of SCNT embryos, and provides evidence that BMP6 is an important determinant of mammalian oocyte developmental reprogramming.
authors.affiliation: 1 Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University , Lanzhou, China .
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Pan
authors.affiliation: 1 Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University , Lanzhou, China .
authors.forename: Honghong
authors.initials: H
authors.lastname: He
authors.affiliation: 1 Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University , Lanzhou, China .
authors.forename: Yan
authors.initials: Y
authors.lastname: Cui
authors.affiliation: 2 University of South Bohemia in České Budějovice , Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Research Institute of Fish Culture and Hydrobiology, Vodňany, Czech Republic .
authors.forename: Abdul Rasheed
authors.initials: AR
authors.lastname: Baloch
authors.affiliation: 1 Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University , Lanzhou, China .
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
authors.affiliation: 1 Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University , Lanzhou, China .
authors.forename: Jiangfeng
authors.initials: J
authors.lastname: Fan
authors.affiliation: 1 Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University , Lanzhou, China .
authors.forename: Junfeng
authors.initials: J
authors.lastname: He
authors.affiliation: 1 Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University , Lanzhou, China .
authors.forename: Sijiu
authors.initials: S
authors.lastname: Yu
mesh_terms: D000818:Animals; D017209:Apoptosis; D001755:Blastocyst / Q000166:cytology; D055418:Bone Morphogenetic Protein 6 / Q000494:pharmacology*; D002417:Cattle; D065150:Cellular Reprogramming; D019976:Cloning, Organism / Q000379:methods*; D004622:Embryo, Mammalian / Q000166:cytology; D005260:Female; D005307:Fertilization in Vitro; D020869:Gene Expression Profiling; D006801:Humans; D008856:Microscopy, Fluorescence; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000166:cytology*; D010053:Ovary / Q000473:pathology; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: C525816:BMP6 protein, human; D055418:Bone Morphogenetic Protein 6; D011994:Recombinant Proteins