Impact of heat stress on germinal vesicle breakdown and lipolytic changes during in vitro maturation of bovine oocytes.

摘要: Two studies were conducted with the overarching goal of determining extent to which lipolytic changes relate germinal vesicle breakdown (GVBD) in bovine oocytes matured under thermoneutral or hyperthermic conditions. To this end, cumulus-oocyte complexes underwent vitro maturation for 0, 2, 4, 6 24 h at 38.5 (first study) and 41.0 C (second study; heat stress applied up through first 12 only, then shifted C). Independent temperature, triglyceride phospholipid content decreased markedly by 2 (hIVM; P < 0.0005). Content was lowest hIVM no detectable impact when exposure occurred during hIVM. Germinal earlier experiencing effects observed as soon 4 (P 0.0001). associated (R2 = 0.2123 0.0030 content; R2 0.2243 0.0026 content). ATP higher 0.0082). In summary, GVBD occurs sooner heat-stressed oocytes. Although marked decreases noted early preceded GVBD, such these are not likely serving an initial driver because similarly