Gahr Scott A, Vallejo Roger L, Weber Gregory M, Shepherd Brian S, Silverstein Jeffrey T, Rexroad Caird E
National Center for Cool and Cold Water Aquaculture, Agriculture Research Service, United States Department of Agriculture, Kearneysville, West Virginia 25430, USA.
Physiol Genomics. 2008 Feb 19;32(3):380-92. doi: 10.1152/physiolgenomics.00142.2007. Epub 2007 Dec 11.
Although studies have established that exogenous growth hormone (GH) treatment stimulates growth in fish, its effects on target tissue gene expression are not well characterized. We assessed the effects of Posilac (Monsanto, St. Louis, MO), a recombinant bovine GH, on tissue transcript levels in rainbow trout selected from two high-growth rate and two low-growth rate families. Transcript abundance was measured in liver and muscle with the Genome Research in Atlantic Salmon Project (GRASP) 16K cDNA microarray. A selection of the genes identified as altered by the microarray and transcripts for insulin-like growth factors, growth hormone receptors (GHRs), and myostatins were measured by real-time PCR in the liver, muscle, brain, kidney, intestine, stomach, gill, and heart. In general, transcripts identified as differentially regulated in the muscle on the microarray showed similar directional changes of expression in the other nonhepatic tissues. A total of 114 and 66 transcripts were identified by microarray as differentially expressed with GH treatment across growth rate for muscle and liver, respectively. The largest proportion of these transcripts represented novel transcripts, followed by immune and metabolism-related genes. We have identified a number of genes related to lipid metabolism, supporting a modulation in lipid metabolism following GH treatment. Most notable among the growth-axis genes measured by real-time PCR were increases in GHR1 and -2 transcripts in liver and muscle. Our results indicate that short-term GH treatment activates the immune system, shifts the metabolic sectors, and modulates growth-regulating genes.
尽管研究已证实外源性生长激素（GH）处理可刺激鱼类生长，但其对靶组织基因表达的影响尚未得到充分表征。我们评估了重组牛生长激素Posilac（孟山都公司，密苏里州圣路易斯）对从两个高生长率和两个低生长率家系中选出的虹鳟鱼组织转录水平的影响。使用大西洋鲑鱼基因组研究计划（GRASP）16K cDNA微阵列测量肝脏和肌肉中的转录本丰度。通过实时PCR测量肝脏、肌肉、脑、肾、肠、胃、鳃和心脏中被微阵列鉴定为发生改变的部分基因以及胰岛素样生长因子、生长激素受体（GHRs）和肌肉生长抑制素的转录本。总体而言，在微阵列上被鉴定为在肌肉中差异调节的转录本在其他非肝脏组织中显示出相似的表达方向变化。通过微阵列鉴定出，分别有114个和66个转录本在GH处理下跨生长率在肌肉和肝脏中差异表达。这些转录本中最大比例代表新转录本，其次是免疫和代谢相关基因。我们鉴定出了一些与脂质代谢相关的基因，支持GH处理后脂质代谢的调节。通过实时PCR测量的生长轴基因中，最显著的是肝脏和肌肉中GHR1和 -2转录本的增加。我们的结果表明，短期GH处理可激活免疫系统、改变代谢部门并调节生长调节基因。
