Ammar Asmma Y, El Nahas Abeer F, Mahmoud Shawky, Barakat Mohamed E, Hassan Asmaa M
Biotechnology department, Animal Health Research Institute, Kafr El Sheikh, Egypt.
Animal Husbandry and Animal Wealth Department, Faculty of Veterinary Medicine, Alexandria University, Edfina, Behera, 22758, Egypt.
Fish Physiol Biochem. 2018 Apr;44(2):515-525. doi: 10.1007/s10695-017-0450-4. Epub 2017 Dec 12.
The aim of this work is to study the effect of the thermal stress of ambient temperature during winter and summer on the expression of type IV antifreeze gene (ANF IV) in different tissues of Nile tilapia (Oreochromis niloticus) as well as some immune-related genes. At first, genomic ANF IV gene was characterized from one fish; 124 amino acids were identified with 92.7% similarity with that on the gene bank. Expression of ANF IV and immune-related genes were done twice, once at the end of December (winter sample, temperature 14 °C) and the other at August (summer sample, temperature 36 °C). Assessment of ANF IV gene expression in different organs of fish was done; splenic mRNA was used for assessment of immune-related gene transcripts (CXCl2 chemokine, cc-chemokine, INF-3A, and MHC IIβ). Winter expression analysis of AFP IV in O. niloticus revealed significant upregulation of mRNA transcript levels in the intestine, gills, skin, spleen, liver, and brain with 324.03-, 170.06-, 107.63-, 97.61-, 94.35-, and 27.85-folds, respectively. Furthermore, upregulation in the gene was observed in some organs during summer: in the liver, gills, skin, intestine, and brain with lower levels compared with winter. The level of expression of immune-related genes in winter is significantly higher than summer in all assessed genes. Cc-chemokine gene expression was the most affected in both winter and summer. Variable expression profile of ANF IV in different organs and in different seasons together with its amino acid similarity of N-terminal and C-terminal with apolipoprotein (lipid binder) and form of high-density lipoprotein (HDL) suggests a different role for this protein which may be related to lipid metabolism.
这项工作的目的是研究冬季和夏季环境温度的热应激对尼罗罗非鱼（Oreochromis niloticus）不同组织中IV型抗冻基因（ANF IV）以及一些免疫相关基因表达的影响。首先，从一条鱼中鉴定出基因组ANF IV基因；鉴定出124个氨基酸，与基因库中的序列相似度为92.7%。对ANF IV和免疫相关基因的表达进行了两次检测，一次在12月底（冬季样本，温度14°C），另一次在8月（夏季样本，温度36°C）。对鱼的不同器官中ANF IV基因的表达进行了评估；脾脏mRNA用于评估免疫相关基因转录本（CXCl2趋化因子、cc趋化因子、INF-3A和MHC IIβ）。尼罗罗非鱼中AFP IV的冬季表达分析显示，肠道、鳃、皮肤、脾脏、肝脏和大脑中的mRNA转录水平显著上调，分别上调了324.03倍、170.06倍、107.63倍、97.61倍、94.35倍和27.85倍。此外，夏季在一些器官中也观察到该基因的上调：在肝脏、鳃、皮肤、肠道和大脑中，上调水平低于冬季。在所有评估的基因中，免疫相关基因在冬季的表达水平显著高于夏季。Cc趋化因子基因的表达在冬季和夏季受到的影响最大。ANF IV在不同器官和不同季节的可变表达谱，以及其N端和C端与载脂蛋白（脂质结合剂）和高密度脂蛋白（HDL）形式的氨基酸相似性，表明该蛋白可能具有与脂质代谢相关的不同作用。
