title: Melatonin promotes the in vitro development of pronuclear embryos and increases the efficiency of blastocyst implantation in murine.
abstract: When a defect occurs in the in vitro development of a pronuclear embryo, the interruption of the subsequent implantation limits the success of assisted conception. This common problem remains to be solved. In this study, we observed that melatonin at its physiological concentration (10(-7)  m) significantly promoted the in vitro development of murine pronuclear embryos. This was indicated by the increased blastocyst rate, hatching blastocyst rate, and blastocyst cell number with melatonin treatment. In addition, when these blastocysts were implanted into female recipient mice, the pregnancy rates (95.0% versus control 67.8%), litter sizes (4.1 pups/litter versus control 2.7 pups/litter), and postnatal survival rates of offspring (96.84% versus control 81.24%) were significantly improved compared with their non-melatonin-treated counterparts. Mechanistic studies revealed that melatonin treatment upregulates gene expression of the antioxidant enzyme, superoxide dismutase (SOD), and the anti-apoptotic factor bcl-2 while downregulating the expression of pro-apoptotic genes p53 and caspase-3. Due to these changes, melatonin treatment reduces ROS production and cellular apoptosis during in vitro embryo development and improves the quality of blastocysts. The implantation of blastocysts with higher quality leads to more healthy offspring and increased pup survival.
authors.affiliation: State Key Laboratory of Animal Nutrition, Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: XiuZhi
authors.initials: X
authors.lastname: Tian
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.forename: DunXian
authors.initials: D
authors.lastname: Tan
authors.forename: Russel J
authors.initials: RJ
authors.lastname: Reiter
authors.forename: GuoShi
authors.initials: G
authors.lastname: Liu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism*; D053148:Caspase 3 / Q000096:biosynthesis; D010064:Embryo Implantation / Q000187:drug effects* / Q000502:physiology; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects* / Q000502:physiology; D008550:Melatonin / Q000494:pharmacology*; D051379:Mice; D011247:Pregnancy; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000096:biosynthesis; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis; D015854:Up-Regulation / Q000187:drug effects* / Q000502:physiology
chemical_list: D000975:Antioxidants; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; C052617:Bcl2 protein, mouse; D013482:Superoxide Dismutase; C505409:Casp3 protein, mouse; D053148:Caspase 3; D008550:Melatonin
keywords: anti-apoptotic; antioxidant; blastocyst transfer; melatonin; murine; pronuclear embryos