Ye Minghui, Lin Xinghua, Zhang Yulei, Huang Yang, Li Guangli, Tian Changxu
Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China.
Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Guangdong Provincial Engineering Laboratory for Mariculture Organism Breeding, Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Zhanjiang 524088, China.
Animals (Basel). 2023 Apr 1;13(7):1232. doi: 10.3390/ani13071232.
Olfactory receptor (OR) genes are essential in the specific recognition of diverse stimuli in fish. In this study, a total of 141 OR genes were identified in silver sillago (), a marine fish sensitive to environmental stimuli, including 112 intact genes, 26 truncated genes, and three pseudogenes. A phylogenetic tree analysis elucidated that the OR genes of were classified into six groups, of which β, γ, δ, ε, and ζ groups belonged to type I, and the η group belonged to type II. The type I OR genes contained almost all conserved motifs ( = 62), while type II OR genes mainly retained conserved motifs 7(3), 1, 10, 4, and 2 ( = 39). OR genes were mainly distributed on LG1, LG9, LG11, and LG12. Of all OR genes, 36.23% (50 genes) showed significant expansion in . Ka/Ks analysis demonstrated that 227 sites were under purifying selection, while 12 sites were under positive selection, including eight genes in the OR2A12 gene subfamily. Sixty-one genes (44.20%) displayed differential expression under hypoxic stress. The identified OR genes explored the mechanism of environmental stress and ecological adaptation of , and provided valuable genomic resources for further research on the olfaction of teleosts.
嗅觉受体（OR）基因在鱼类对多种刺激的特异性识别中至关重要。在本研究中，在对环境刺激敏感的海洋鱼类银鲈中总共鉴定出141个OR基因，其中包括112个完整基因、26个截短基因和3个假基因。系统发育树分析表明，银鲈的OR基因被分为六组，其中β、γ、δ、ε和ζ组属于I型，而η组属于II型。I型OR基因包含几乎所有保守基序（n = 62），而II型OR基因主要保留保守基序7（3）、1、10、4和2（n = 39）。OR基因主要分布在LG1、LG9、LG11和LG12上。在所有OR基因中，36.23%（50个基因）在银鲈中显示出显著扩增。Ka/Ks分析表明，227个位点受到纯化选择，而12个位点受到正选择，包括OR2A12基因亚家族中的8个基因。61个基因（44.20%）在低氧胁迫下表现出差异表达。鉴定出的OR基因揭示了银鲈的环境应激和生态适应机制，并为进一步研究硬骨鱼类的嗅觉提供了有价值的基因组资源。
