1. Linoleic acid stimulates neutral lipid accumulation in lipid droplets of maturing bovine oocytes
- Author
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Maria de Las Mercedes Carro, Gerardo Martin Oresti, Glenda Laura Rios, Jorgelina Buschiazzo, and Ricardo Alberio
- Subjects
Cytoplasm ,OOCYTES ,Linoleic acid ,LINOLEIC ACID ,Biology ,Fatty Acids, Nonesterified ,Linoleic Acid ,Ciencias Biológicas ,chemistry.chemical_compound ,Food Animals ,Lipid droplet ,medicine ,Animals ,Carbon Radioisotopes ,Small Animals ,Cells, Cultured ,Triglycerides ,chemistry.chemical_classification ,Cell Nucleus ,Germinal vesicle ,Dose-Response Relationship, Drug ,Equine ,Fatty acid ,Lipid metabolism ,Bioquímica y Biología Molecular ,Oocyte ,Lipid Metabolism ,Lipids ,In vitro maturation ,Culture Media ,medicine.anatomical_structure ,chemistry ,Biochemistry ,Isotope Labeling ,Oocytes ,LIPID DROPLETS ,lipids (amino acids, peptides, and proteins) ,Animal Science and Zoology ,Cattle ,Female ,IN VITRO MATURATION ,CIENCIAS NATURALES Y EXACTAS ,Polyunsaturated fatty acid - Abstract
Linoleic acid (LA) is a polyunsaturated fatty acid present in high concentrations in bovine follicular fluid; when added to maturation culture media, it affects oocyte competence (depending on the type and concentration of LA used). To date, little is known about the effective level of incorporation of LA and there is apparently no information regarding its esterification into various lipid fractions of the oocyte and its effect on neutral lipid storage. Therefore, the objective was to assess the uptake and subcellular lipid distribution of LA by analyzing incorporation of radiolabeled LA into oocyte polar and neutral lipid classes. The effects of various concentrations of LA on the nuclear status and cytoplasmic lipid content of bovine oocytes matured in vitro was also analyzed, with particular emphasis on intermediate concentrations of LA. Neutral lipids stored in lipid droplets were quantified with a fluorescence approach. Linoleic acid at 9 and 43 μM did not affect the nuclear status of oocytes matured in vitro, and 100 μM LA inhibited germinal vesicle breakdown, resulting in a higher percentage of oocytes arrested at the germinal state (43.5 vs. 3.0 in controls; P < 0.05). Bovine oocytes actively incorporated LA from the maturation medium (83.4 pmol LA per 100 oocytes at 22 hours of incubation; P < 0.05) and metabolized it mainly into major lipid classes, e.g., triacylglycerols and phospholipids (61.1% and 29.3%, respectively). Supplementation of the maturation medium with LA increased triacylglycerol accumulation in cytoplasmic lipid droplets at all concentrations assayed (P < 0.05). In conclusion, LA added to a defined maturation medium at concentrations that did not alter the nuclear status of bovine oocytes matured in vitro (9 and 43 μM) improved their quality by increasing the content of neutral lipids stored in lipid droplets. By directing the free fatty acid (LA) to triacylglycerol synthesis pathways and increasing the degree of unsaturation of membrane phospholipids, the oocyte was protected from lipotoxic effects (with an expectation of improved cryotolerance). Fil: Carro, Maria de Las Mercedes. Instituto Nacional de Tecnologia Agropecuaria. Centro Reg.buenos Aires. Estacion Exptal.agrop.balcarce. Laboratorio de Biotecnologia de la Reproduccion; Argentina Fil: Buschiazzo, Jorgelina. Instituto Nacional de Tecnologia Agropecuaria. Centro Reg.buenos Aires. Estacion Exptal.agrop.balcarce. Laboratorio de Biotecnologia de la Reproduccion; Argentina. Consejo Nacional de Investigaciones Cientificas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto de Investigaciones Bioquímicas Bahia Blanca (i); Argentina Fil: Rios, Glenda Laura. Instituto Nacional de Tecnologia Agropecuaria. Centro Reg.buenos Aires. Estacion Exptal.agrop.balcarce. Laboratorio de Biotecnologia de la Reproduccion; Argentina Fil: Oresti, Gerardo Martin. Consejo Nacional de Investigaciones Cientificas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto de Investigaciones Bioquímicas Bahia Blanca (i); Argentina Fil: Alberio, R. H.. Instituto Nacional de Tecnologia Agropecuaria. Centro Reg.buenos Aires. Estacion Exptal.agrop.balcarce. Laboratorio de Biotecnologia de la Reproduccion; Argentina
- Published
- 2013