title: Haploid parthenotes express differential response to in vitro exposure of ammonia compared to normally fertilized embryos.
abstract: In the present study, we assessed whether absence of paternal genome imparts any differential response in embryos to chemical stress such as ammonia. Parthenogenesis was induced in MII stage oocytes using 10 mM SrCl2in M16 medium. Parthenotes and normally fertilized embryos at 2 cell stage were exposed to different concentrations of ammonia and cultured till blastocyst. Exposure of ammonia to normally fertilized embryos resulted in significant decrease in the developmental potential (p < 0.0001) and blastocyst quality (p < 0.001). Whereas, in parthenotes, even though lower concentrations of ammonia did not have any effect, at 200 μM concentration the blastocyst rate was two times higher than control. The baseline apoptotic index was higher in parthenotes compared to normally fertilized embryos, which further increased after ammonium exposure (p < 0.001). Unlike in normally fertilized embryos ammonia exposure altered the mitochondrial distribution pattern and lead to increased expression of Oct4, Nanog and Na+/K+ion exchange channel, while the cytochrome C expression was downregulated. This indicates that haploidy and/or absence of paternal factors in the embryo results in differential tolerance to stress induced by ammonia.
authors.affiliation: Clinical Embryology, Kasturba Medical College, Manipal University, Manipal 576104, India.
authors.forename: Ramya
authors.initials: R
authors.lastname: Nair
authors.affiliation: Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal 576104, India.
authors.forename: Srinivas
authors.initials: S
authors.lastname: Mutalik
authors.affiliation: Department of Chemistry, Mangalore University, Mangalagangothri 574199, Karnataka, India.
authors.forename: Jagadeesh Prasad
authors.initials: JP
authors.lastname: Dasappa
authors.affiliation: Clinical Embryology, Kasturba Medical College, Manipal University, Manipal 576104, India. Electronic address: guru.kalthur@manipal.edu.
authors.forename: Guruprasad
authors.initials: G
authors.lastname: Kalthur
authors.affiliation: Clinical Embryology, Kasturba Medical College, Manipal University, Manipal 576104, India.
authors.forename: Satish Kumar
authors.initials: SK
authors.lastname: Adiga
mesh_terms: D000641:Ammonia / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism; D004171:Diploidy; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism*; D005260:Female; D005306:Fertilization; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D006238:Haploidy; D008297:Male; D051379:Mice; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D000071317:Nanog Homeobox Protein / Q000235:genetics / Q000378:metabolism; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010312:Parthenogenesis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics / Q000378:metabolism
chemical_list: D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; D000641:Ammonia; D000254:Sodium-Potassium-Exchanging ATPase
keywords: Ammonia; Apoptosis; Haploidy; Parthenogenesis; Stress response