Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1C 5S7.
Comp Biochem Physiol Part D Genomics Proteomics. 2009 Jun;4(2):128-38. doi: 10.1016/j.cbd.2008.12.007. Epub 2009 Jan 10.
Expression level of genes associated with oxygen [cytochrome oxidase 1 (COX1) and myoglobin (Mb)] and glucose utilization [glucose transporters (GLUTs) and hexokinases (HKs)] along with metabolic indices were determined in Atlantic cod (Gadus morhua) subjected to an hypoxic challenge of <45% oxygen saturation for 24 days. There were two closely related HKs considered to be homologues of mammalian HKIs. HKIa and HKIb share 86% sequence identity and are both ubiquitously expressed. Mb was also expressed in many tissues with highest levels occurring in heart. Over the first 15 days of hypoxia there were transient increases in plasma lactate in hypoxic relative to normoxic fish associated with a significant decrease in liver glycogen. Over days 1-6, there were in ten of eleven cases, increased average (with a number of conditions being statistically significant) expression levels of GLUTs (1, 2, 4) and HKs (1a and b) in gill, heart, liver, and white muscle in hypoxic relative to normoxic fish. There were significant increases in COX1 and Mb expression levels in gill by day 24 but no changes in these aerobic indicators in heart or liver. Overall the data suggest a transient increase in genes associated with glucose utilization during the early part of the hypoxic challenge followed by alterations in gene expression in gill.
在经历 24 天 <45%氧气饱和度的缺氧挑战后，我们测定了大西洋鳕鱼（Gadus morhua）中与氧气（细胞色素氧化酶 1 (COX1) 和肌红蛋白 (Mb)）和葡萄糖利用（葡萄糖转运蛋白 (GLUTs) 和己糖激酶 (HKs)）相关的基因的表达水平以及代谢指标。有两种密切相关的 HK 被认为是哺乳动物 HKIs 的同源物。HKIa 和 HKIb 具有 86%的序列同一性，并且均广泛表达。Mb 也在许多组织中表达，其中心脏中的表达水平最高。在缺氧的前 15 天中，与正常氧鱼相比，缺氧鱼的血浆乳酸水平短暂升高，同时肝糖原显著减少。在第 1-6 天期间，在十一种情况下有十一种情况，与正常氧鱼相比，缺氧鱼的鳃、心脏、肝脏和白肌中的 GLUTs（1、2、4）和 HKs（1a 和 b）的平均表达水平（在某些情况下具有统计学意义）增加。到第 24 天，鳃中的 COX1 和 Mb 表达水平显著增加，但心脏或肝脏中这些需氧指标没有变化。总体而言，数据表明在缺氧挑战的早期阶段，与葡萄糖利用相关的基因表达短暂增加，随后在鳃中发生基因表达的改变。
