Juanita L Edwards

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The authors sought to determine whether developmental differences in the magnitude of embryonic mortality caused by heat stress in vivo are caused by changes in resistance of embryos to elevated temperature. In this regard, responses of oocytes, two-cell embryos, four-to eight-cell embryos, and compacted morulae to heat shock were compared. An additional(More)
Continuous cultures of bovine trophectoderm (CT-1 and CT-5) and bovine endoderm (CE-1 and CE-2) were initiated and maintained on STO feeder cells. CT-1 and CT-5 were derived from the culture of intact, 10- to 11-day in vitro-produced blastocysts. CE-1 and CE-2 were derived from the culture of immunodissected inner cell masses of 7- to 8-day in(More)
Delineation of maternal versus direct effects of heat stress in reducing development at the germinal vesicle (GV) stage is challenging, because oocytes spontaneously resume meiosis after removal from antral follicles. The use of S-roscovitine (inhibitor of p34(cdc2)/cyclin B kinase) to hold bovine oocytes at the GV stage without compromising early embryo(More)
Normal mitochondrial activity is a critical component of neuronal metabolism and function. Disruption of mitochondrial activity by altered mitochondrial fission and fusion is the root cause of both neurodegenerative disorders and Charcot–Marie–Tooth type 2A inherited neuropathy. This study addressed the role of mitochondrial fission in the pathogenesis of(More)
Exposure of heifers to heat stress during oocyte maturation leads to embryos with reduced development. The objectives of the present study were threefold: 1) to evaluate effects of heat shock on oocyte function as assessed by cleavage and development, and associated effects on membrane integrity and protein synthesis, 2) to determine whether responses of(More)
The objectives of this study were to evaluate: 1) effects of a physiologically relevant elevated temperature on in vitro development of maturing oocytes, 2) effects of retinol on in vitro development of maturing oocytes, and 3) effects of retinol to improve development of oocytes compromised by an elevated temperature. Bovine oocytes were matured for 24 h(More)
The objective of this study was to evaluate nuclear (progression to metaphase II) and cytoplasmic (translocation of cortical granules to the oolemma) maturation in control (38.5 degrees C) and heat-stressed (41.0 degrees C) oocytes. Hoechst staining indicated that a similar proportion of control and heat-stressed oocytes progressed to meta-phase II. More(More)
Retinoids are recognized as important regulators of vertebrate development, cell differentiation, and tissue function. Previous studies, performed both in vivo and in vitro, indicate that retinoids influence several reproductive events, including follicular development, oocyte maturation and early embryonic development. The present study evaluated in vitro(More)
Consequences of heat stress exposure during the first 12 h of meiotic maturation differed depending on how and when bovine oocytes were activated. If heat-stressed oocytes underwent IVF at ~24 h, blastocyst development was less than for respective controls and similar to that obtained for nonheat-stressed oocytes undergoing IVF at 30 h (i.e. slightly aged).(More)
This study examined whether development of bovine in vitro produced (IVP) blastocysts in the sheep uterus resulted in morphologically and karyotypically normal elongation stage bovine blastocysts. Seven day IVP bovine blastocysts, resulting from either in vitro maturation and fertilization, nuclear transfer (NT), or parthenogenic activation, were surgically(More)