Heat stress impairs gap junction communication and cumulus function of bovine oocytes.

Autor:	Campen KA; Department of Animal Science, The University of Tennessee, Institute of Agriculture, AgResearch, Knoxville, TN 37996-4574, USA., Abbott CR; Department of Animal Science, The University of Tennessee, Institute of Agriculture, AgResearch, Knoxville, TN 37996-4574, USA., Rispoli LA; Department of Animal Science, The University of Tennessee, Institute of Agriculture, AgResearch, Knoxville, TN 37996-4574, USA., Payton RR; Department of Animal Science, The University of Tennessee, Institute of Agriculture, AgResearch, Knoxville, TN 37996-4574, USA., Saxton AM; Department of Animal Science, The University of Tennessee, Institute of Agriculture, AgResearch, Knoxville, TN 37996-4574, USA., Edwards JL; Department of Animal Science, The University of Tennessee, Institute of Agriculture, AgResearch, Knoxville, TN 37996-4574, USA.
Jazyk:	angličtina
Zdroj:	The Journal of reproduction and development [J Reprod Dev] 2018 Oct 12; Vol. 64 (5), pp. 385-392. Date of Electronic Publication: 2018 Jun 25.
DOI:	10.1262/jrd.2018-029
Abstrakt:	The intimate association of cumulus cells with one another and with the oocyte is important for regulating oocyte meiotic arrest and resumption. The objective of this study was to determine the effects of heat stress on cumulus cell communication and functions that may be related to accelerated oocyte meiosis during early maturation. Bovine cumulus-oocyte complexes underwent in vitro maturation for up to 6 h at thermoneutral control (38.5°C) or elevated (40.0, 41.0 or 42.0°C) temperatures. Gap junction communication between the cumulus cells and the oocyte was assessed using the fluorescent dye calcein after 4 h of in vitro maturation. Dye transfer was reduced in cumulus-oocyte complexes matured at 41.0°C or 42.0°C; transfer at 40.0°C was similar to control (P < 0.0001). Subsequent staining of oocytes with Hoechst revealed that oocytes matured at 41.0 or 42.0°C contained chromatin at more advanced stages of condensation. Maturation of cumulus-oocyte complexes at elevated temperatures reduced levels of active 5' adenosine monophosphate activated kinase (P = 0.03). Heat stress exposure had no effect on active extracellular-regulated kinase 1/2 in oocytes (P = 0.67), associated cumulus cells (P = 0.60) or intact cumulus-oocyte complexes (P = 0.44). Heat-induced increases in progesterone production by cumulus-oocyte complexes were detected during the first 6 h of maturation (P = 0.001). Heat-induced alterations in gap junction communication and other cumulus-cell functions likely cooperate to accelerate bovine oocyte meiotic progression.
Databáze:	MEDLINE
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