Impact of linoleic acid on bovine oocyte maturation and embryo development

Abstract

Linoleic acid (LA; 18:2 n-6) is the most abundant fatty acid in bovine follicular fluid, and it was previously reported that LA concentration significantly decreases when follicle size increases. This suggests that LA may have a role in the regulation of oocyte maturation. The present study investigated the effect of LA supplementation on bovine oocyte maturation and early embryo development in vitro. Treatment of cumulus-oocyte complexes (COCs) with LA significantly inhibited cumulus cell expansion and retarded development of the oocytes to the metaphase II (MII) stage in a dose-dependent manner. This effect was reversible, and the oocytes developed to the MII stage after extended culture in the absence of LA. Treatment of COCs with LA also resulted in a significantly lower percentage of cleaved embryos and blastocyst yield. Furthermore, COCs treated with LA had significant effects compared with controls in i) increasing prostaglandin E 2 concentration in the medium, ii) decreasing intracellular cAMP at 6 and 24 h of maturation and iii) decreasing phosphorylation of the MAPK1 and 3 at 24 h, and AKT at 6 h of maturation. In conclusion, LA supplementation to bovine oocytes during maturation altered the molecular mechanisms regulating oocyte maturation and resulted in decreased percentage of oocytes at MII stage and inhibition of the subsequent early embryo development. These data provide evidence for adverse effects of LA on oocyte development, which can be associated with dietary increased level of LA in the follicular fluid and the decline in fertility in farm animals and human.Reproduction (2010) 139 979-988

Role of PTGS2-generated PGE2 during gonadotrophin-induced bovine oocyte maturation and cumulus cell expansion

“…The primer set used was also able to detect other C members (AKR1C1 and AKR1C4), producing the same PCR product size. Since this study group has previously detected PGF 2a in spent media at 24 h of bovine oocyte maturation (Marei et al, 2010), this suggests that PGFS in COC belong to a different isoform. Other enzymes like AKR1B5 have been identified as functional PGFS in bovine endometrium (Madore et al, 2003) and may be functional in COC as well.…”

Effect of Linolenic acid during in vitro maturation of ovine oocytes: embryonic developmental potential and mRNA abundances of genes involved in apoptosis

“…In the former study, alteration of PUFAs through the dietary sources of FAs led to improvement of oocyte development potential [7]. In bovine species, supplementation of maturation medium with essential fatty acids has been shown to have positive [3] or negative [4] effects on oocyte developmental competence depending on the type of fatty acid studied.…”

“…Previous reports have shown that supplementary fatty acids have significant effects on oocyte maturation and subsequent pre-implantation development [2][3][4][5].…”

Impact of contrasting fish oil concentrations in the diet on ovine embryo development <i>in vivo</i> and of corresponding diet-specific derivative sera during <i>in vitro</i> culture

“…Bilby et al (2005Bilby et al ( , 2006 reported that dairy cows given a diet enriched with linoleic acid tended to yield aspirated oocytes with a subsequently slower rate of in vitro embryo development than those from cows given an oleic acid-enriched diet. Linoleic acid supplementation of an in vitro culture medium (Marei et al, 2010) confirmed its inhibitory effect on bovine oocytes and early embryos. In contrast, the same group had previously found that supplementation with α-linolenic acid enhanced maturation rate and increased bovine blastocyst yield (Marei et al, 2009).…”