Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.3.3.1 (citrate synthase)
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Adult animal cloning has progressed to allow the production of offspring cloned from adult cells, however many cloned calves die prenatally or shortly after birth. This study examined the expression of three important metabolic enzymes, lactate dehydrogenase (LDH), citrate synthase, and phosphofructokinase (PFK), to determine if their detection in nuclear transfer (NT) embryos mimics that determined for in vitro produced embryos. A day 40 nuclear transfer produced fetus derived from an adult cell line was collected and fetal fibroblast cultures were established and maintained. Reconstructed NT embryos were then produced from this cell line, and RT-PCR was used to evaluate mRNA reprogramming. All three mRNAs encoding these enzymes were detected in the regenerated fetal fibroblast cell line. Detection patterns were first determined for IVF produced embryos (1-cell, 2-cell, 6-8 cell, morula, and blastocyst stages) to compare with their detection in NT embryos. PFK has three subunits: PFK-L, PFK-M, and PFK-P. PFK-L and PFK-P were not detected in bovine oocytes. PFK subunits were not detected in 6-8 cell embryos but were detected in blastocysts. Results from NT embryo RT-PCR demonstrated that PFK was not detected in 8-cell NT embryos but was detected in NT blastocysts indicating that proper nuclear reprogramming had occurred. Citrate synthase was detected in oocytes and throughout development to the blastocyst stage in both bovine IVF and NT embryos. LDH-A and LDH-B were detected in bovine oocytes and in all stages of IVF and NT embryos examined up to the blastocyst stage. A third subunit, LDH-C was not detected at the blastocyst stage in IVF or NT embryos but was detected in all earlier stages and in mature oocytes. In addition, LDH-C mRNA was detected in gonad isolated from the NT and an in vivo produced control fetus. These results indicate that the three metabolic enzymes maintain normal expression patterns and therefore must be properly reprogrammed following nuclear transfer.
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PMID:Genetic reprogramming of lactate dehydrogenase, citrate synthase, and phosphofructokinase mRNA in bovine nuclear transfer embryos produced using bovine fibroblast cell nuclei. 1091 95

The scorpaenid fishes Sebastolobus alascanus and Scorpaena guttata have similar life styles but differ in their depth distributions: S. guttata lives in shallow water (< 180 m); adult S. alascanus occur predominantly on the upper continental slope (400-1200 m) where the oxygen minimum zone (OMZ) prevails and ambient temperature is much colder. Respiratory properties and the activities of heart-tissue enzymes of these species were compared to determine the effect of different thermal and ambient O2 regimens on metabolism. Measured over the appropriate habitat temperature ranges, the oxygen consumption (VO2) of S. alascanus is two to four times less than that of S. guttata. Correction for differences in habitat temperature accounted for over 50% of this reduction. The depth-related decrease in VO2 for these two benthic fishes is less than that observed for pelagic fishes. The VO2 of S. guttata decreases at O2 concentrations below 1 ml/l, whereas the VO2 of S. alascanus is regulated down to 0.3 ml/l. The ventilation frequency (Vf) of both species increases in progressive hypoxia; but at < 0.5 ml/l, the Vf of S. guttata declines, while that of S. alascanus does not. When measured at the same temperature, pH and CO2, the blood-O2 affinity of S. guttata is significantly lower than that of S. alascanus. The anaerobic/aerobic enzyme activity ratio of pyruvate kinase to citrate synthase, which correlates with the ability of heart tissue to tolerate hypoxia, is significantly higher for S. alascanus than S. guttata. Lactate dehydrogenase (LDH) activity in freshly collected S. alascanus is also significantly above that of specimens acclimated to normoxic water in the laboratory. Only the skeletal muscle isozyme of LDH (LDH-A) is present in the heart of S. alascanus, whereas S. guttata has both LDH-A and heart (LDH-B) isozymes. Data for metabolic rate, critical O2 tension, blood oxygen affinity, and heart metabolic enzyme profiles all show essential adaptations of S. alascanus for life in the OMZ.
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PMID:Respiratory, Blood, and Heart Enzymatic Adaptations of Sebastolobus alascanus (Scorpaenidae; Teleostei) to the Oxygen Minimum Zone: A Comparative Study. 2930 May 2