Bovine oocytes show a higher tolerance to heat shock in the warm compared with the cold season of the year

Effects of short-term exposure of mature oocytes to sodium nitroprusside on in vitro embryo production and gene expression in bovine

“…The short-term exposure of bovine oocytes to external stress can activate endogenous mechanisms that improve oocyte competence and in vitro embryo development [2,[4][5][6][7][8]. In the present study, we investigated the effect of shortterm exposure of mature bovine oocytes to different Table 2 In vitro embryo production after short-term exposure of mature oocytes to different sodium nitroprusside (SNP) concentrations (data from 10 replicates).…”

“…In this study, SNP treatments induced no change in the relative expression of genes involved in the cell stress tolerance (HSP70 and HSP90), oxidative stress (HIF1A and PRDX5), or apoptosis (BCL2A1) of expanded blastocysts. Heat shock proteins have been implicated in embryo [34,35] and oocyte thermotolerance [7], in high hydrostatic pressure tolerance [4], and in the oxidative stress response [36]. Similarly, the expression of hypoxia-inducible factors has been described as a protective mechanism against oxidative stress conditions in somatic cells [37,38] and embryos [8,[39][40][41].…”

“…The viability and developmental competence of oocytes can be enhanced by inducing their stress tolerance through exposure to high hydrostatic pressure [2,4,5], osmotic agents [5,6], heat shock [7], and reactive oxygen species [8].…”

Maternal control of oocyte quality in cattle “a review”

“…However, several studies indicated that heat shock impairs both cytoplasmic and nuclear maturation of bovine oocytes (Andreu-Vázquez et al, 2010;Maya-Soriano et al, 2013). Elevated temperature affects microtubules and microfilaments organization (Ju et al, 2005).…”

Gene expression profile in heat-shocked Holstein and Nelore oocytes and cumulus cells

“…Heat-induced damage in bovine oocytes causes cytoplasmic changes, such as a reduction in oocyte protein synthesis (Edwards and Hansen 1996), disorganisation of microfilaments and microtubules (Roth and Hansen 2005), changes in cortical granule redistribution (Maya-Soriano et al 2013) and a reduction in mitochondrial activity (Paula-Lopes et al 2013). Heat shock also affects nuclear events, reducing oocyte meiotic maturation (Roth and Hansen 2005) and inducing DNA fragmentation (Roth and Hansen 2004).…”