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936782 
Journal Article 
Dietary omega-3 and -6 polyunsaturated fatty acids affect the composition and development of sheep granulosa cells, oocytes and embryos 
Wonnacott, KE; Kwong, WY; Hughes, J; Salter, AM; Lea, RG; Garnsworthy, PC; Sinclair, KD 
2010 
1 
Reproduction
ISSN: 1470-1626
EISSN: 1741-7899 
139 
1 
57-69 
English 
19789173 
WOS:000273335100006 
The evidence that omega-3 (n-3) and -6 (n-6) polyunsaturated fatty acids (PUFAs) have differential effects on ovarian function, oocytes and embryo quality is inconsistent. We report on the effects of n-3 versus n-6 PUFA-enriched diets fed to 36 ewes over a 6-week period, prior to ovarian stimulation and follicular aspiration, on ovarian steroidogenic parameters and embryo quality. Follicle number and size were unaltered by diet, but follicular-fluid progesterone concentrations were greater in n-3 PUFA-fed ewes than in n-6 PUFA-fed ewes. The percentage of saturated FAs (mostly stearic acid) was greater in oocytes than in either granulosa cells or plasma, indicating selective uptake and/or de novo synthesis of saturated FAs at the expense of PUFAs by oocytes. High-density lipoproteins (HDLs) fractionated from sera of these ewes increased granulosa cell proliferation and steroidogenesis relative to the FA-free BSA control during culture, but there was no differential effect of n-3 and n-6 PUFAs on either oestradiol or progesterone production. HDL was ineffective in delivering FAs to embryos during culture, although n-6 PUFA HDL reduced embryo development. All blastocysts, irrespective of the treatment, contained high levels of unsaturated FAs, in particular linoleic acid. Transcripts for HDL and low-density lipoprotein (LDL) receptors (SCARB1 and LDLR) and stearoyl-CoA desaturase (SCD) are reported in sheep embryos. HDL reduced the expression of transcripts for LDLR and SCD relative to the BSA control. The data support a differential effect of n-3 and n-6 PUFAs on ovarian steroidogenesis and pre-implantation development, the latter in the absence of a net uptake of FAs. 
Animals; Cell Proliferation; Cells, Cultured; Cholesterol; Dietary Fats, Unsaturated; Embryo, Mammalian; Embryonic Development; Fatty Acids; Fatty Acids, Omega-3; Fatty Acids, Omega-6; Female; Fish Oils; Follicular Fluid; Gene Expression Regulation, Developmental; Gonadal Steroid Hormones; Granulosa Cells; Lipoproteins; Oocytes; Ovary; Ovulation Induction; Plant Oils; Random Allocation; Sheep, Domestic; Ovis aries; estradiol; high density lipoprotein; high density lipoprotein cholesterol; low density lipoprotein cholesterol; low density lipoprotein receptor; monounsaturated fatty acid; omega 3 fatty acid; omega 6 fatty acid; polyunsaturated fatty acid; progesterone; saturated fatty acid; scavenger receptor BI; stearic acid; unsaturated fatty acid; animal cell; animal experiment; article; blastocyst; cholesterol blood level; controlled study; dietary intake; embryo; embryo culture; embryo development; estrogen synthesis; ewe; fatty acid blood level; fatty acid synthesis; genetic transcription; granulosa cell; nonhuman; nucleotide sequence; oocyte development; ovary follicle fluid; ovary follicle maturation; priority journal; progesterone synthesis; steroidogenesis