Seasonal changes in bovine fertility: relation to developmental competence of oocytes, membrane properties and fatty acid composition of follicles

Zeron, Yoel; Ocheretny, A; Kedar, Orit; Borochov, Amihud; Sklan, D.; Arav, Amir

doi:10.1530/rep.0.1210447

Cited by 242 publications

(134 citation statements)

References 24 publications

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“…The present study also revealed that IVM and IVF of buffalo oocytes during HP decreased (P \ 0.05) cleavage rate and embryo development. Moreover, studies in bovine (Rivera and Hansen 2001;Zeron et al 2001;Jousan and Hansen 2007) have shown similar results. The present findings, therefore, provide clear evidence of a carry-over effect of summer stressed oocytes, or maternal hyperthermia, up to blastocyst stage with a decrease in number at each stage of development.…”

Section: Discussionsupporting

confidence: 56%

Developmental competence and expression profile of genes in buffalo (Bubalus bubalis) oocytes and embryos collected under different environmental stress

et al. 2016

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The study examined the effects of different environmental stress on developmental competence and the relative abundance (RA) of various gene transcripts in oocytes and embryos of buffalo. Oocytes collected during cold period (CP) and hot period (HP) were matured, fertilized and cultured in vitro to blastocyst hatching stage. The mRNA expression patterns of genes implicated in developmental competence (OCT-4, IGF-2R and GDF-9), heat shock (HSP-70.1), oxidative stress (MnSOD), metabolism (GLUT-1), pro-apoptosis (BAX) and anti-apoptosis (BCL-2) were evaluated in immature and matured oocytes as well as in pre-implantation stage embryos. Oocytes reaching MII stage, cleavage rates, blastocyst yield and hatching rates increased (P \ 0.05) during the CP. In MII oocytes and 2-cell embryos, the RA of OCT-4, IGF-2R, GDF-9, MnSOD and GLUT-1 decreased (P \ 0.05) during the HP. In 4-cell embryos, the RA of OCT-4, IGF-2R and BCL-2 decreased (P \ 0.05) in the HP, whereas GDF-9 increased (P \ 0.05). In 8-to 16-cell embryos, the RA of OCT-4 and BCL-2 decreased (P \ 0. 05) in the HP, whereas HSP-70.1 and BAX expression increased (P \ 0.05). In morula and blastocyst, the RA of OCT-4, IGF-2R and MnSOD decreased (P \ 0.05) during the HP, whereas HSP-70.1 was increased (P \ 0.05). In conclusion, deleterious seasonal effects induced at the GVstage carry-over to subsequent embryonic developmental stages and compromise oocyte developmental competence and quality of developed blastocysts.

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Section: Discussionsupporting

confidence: 56%

Developmental competence and expression profile of genes in buffalo (Bubalus bubalis) oocytes and embryos collected under different environmental stress

et al. 2016

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“…Interestingly, there are also seasonal changes in the fatty acid composition of bovine ovarian follicles. Namely, the levels of all fatty acids analysed were increased in follicular fluid in winter compared with summer (Zeron et al 2001). Furthermore, granulosa cells and oocytes isolated in summer had a higher percentage of saturated membrane phospholipids, particularly palmitic acid, while in winter they had a greater percentage of unsaturated phospholipids, particularly 16:1, 18:1, 18:2 (Zeron et al 2001).…”

Section: Diet and Body Compositionmentioning

confidence: 89%

“…Namely, the levels of all fatty acids analysed were increased in follicular fluid in winter compared with summer (Zeron et al 2001). Furthermore, granulosa cells and oocytes isolated in summer had a higher percentage of saturated membrane phospholipids, particularly palmitic acid, while in winter they had a greater percentage of unsaturated phospholipids, particularly 16:1, 18:1, 18:2 (Zeron et al 2001). These differences significantly alter the biophysical behaviour of the oocytes, but it is unclear how this may be related to seasonal differences in diet and the observed better developmental competence of oocytes isolated in winter.…”

Section: Diet and Body Compositionmentioning

confidence: 89%

Lipids and oocyte developmental competence: the role of fatty acids and β-oxidation

2014

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Metabolism and ATP levels within the oocyte and adjacent cumulus cells are associated with quality of oocyte and optimal development of a healthy embryo. Lipid metabolism provides a potent source of energy and its importance during oocyte maturation is being increasingly recognised. The triglyceride and fatty acid composition of ovarian follicular fluid has been characterised for many species and is influenced by nutritional status (i.e. dietary fat, fasting, obesity and season) as well as lactation in cows. Lipid in oocytes is a primarily triglyceride of specific fatty acids which differ by species, stored in distinct droplet organelles that re-localise during oocyte maturation. The presence of lipids, particularly saturated vs unsaturated fatty acids, in in vitro maturation systems affects oocyte lipid content as well as developmental competence. Triglycerides are metabolised by lipases that have been localised to cumulus cells as well as oocytes. Fatty acids generated by lipolysis are further metabolised by b-oxidation in mitochondria for the production of ATP. b-oxidation is induced in cumulus-oocyte complexes (COCs) by the LH surge, and pharmacological inhibition of b-oxidation impairs oocyte maturation and embryo development. Promoting b-oxidation with L-carnitine improves embryo development in many species. Thus, fatty acid metabolism in the mammalian COC is regulated by maternal physiological and in vitro environmental conditions; and is important for oocyte developmental competence.

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“…Embryos collected during the rainy season had a lower number of apoptotic cells, both following IVC and after freezing (Marquez et al 2005). In cattle, a clear seasonality was found between summer and winter oocytes in a wide variety of measures, including conception rate, number of 2-8 mm follicles per ovary, percentage of ovaries with fewer than ten follicles, number of oocytes recovered per ovary, and cleavage rate following chemical activation all the way through to the blastocyst stage (Zeron et al 2001). The authors suggested that these differences were related to differences found in membrane phospholipids' composition being richer in saturated fatty acids in the summer and in mono-and polyunsaturated fatty acids in the winter.…”

Section: Seasonmentioning

confidence: 98%

Current progress in oocyte and embryo cryopreservation by slow freezing and vitrification

2011

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Preservation of female genetics is currently done primarily by means of oocyte and embryo cryopreservation. The field has seen much progress during its four-decade history, progress driven predominantly by research in humans, cows, and mice. Two basic cryopreservation techniques rule the field -controlled-rate freezing, the first to be developed, and vitrification, which, in recent years, has gained a foothold. While much progress has been achieved in human medicine, the cattle industry, and in laboratory animals, this is far from being the case for most other mammals and even less so for other vertebrates. The major strides and obstacles in human and other vertebrate oocyte and embryo cryopreservation will be reviewed here.

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Seasonal changes in bovine fertility: relation to developmental competence of oocytes, membrane properties and fatty acid composition of follicles

Abstract: Reproduction (

Cited by 242 publications

References 24 publications

Developmental competence and expression profile of genes in buffalo (Bubalus bubalis) oocytes and embryos collected under different environmental stress

Developmental competence and expression profile of genes in buffalo (Bubalus bubalis) oocytes and embryos collected under different environmental stress

Lipids and oocyte developmental competence: the role of fatty acids and β-oxidation

Current progress in oocyte and embryo cryopreservation by slow freezing and vitrification

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