Chakkalakkal George Joseph, Gopakumar Sumithra Thangalazhy, Sharma S R Krupesha, Raveendranathan Dhanutha Nikathil, Jagannivasan Amritha, Nair Anusree Velappan, Ramachandran Vishnu, Achamveetil Gopalakrishnan
Marine Biotechnology, Fish Health, and Nutrition Division, ICAR-Central Marine Fisheries Research Institute, Post Box No. 1603, Ernakulam North P.O, Kochi, 682 018, India.
Cochin University of Science and Technology, Kochi, Kerala, 682022, India.
Mol Biol Rep. 2024 Dec 24;52(1):79. doi: 10.1007/s11033-024-10180-w.
Interleukin 10 (IL-10) is uniquely positioned in the immune regulation of teleosts. Modifying the IL-10 pathway changes the teleost's disease susceptibility; however, there is no data on its post-transcriptional regulation. Trachinotus blochii is a high-value mariculture species.
The full-length tbil-10 gene was generated through the Rapid Amplification of cDNA Ends-PCR. After the detailed sequence analysis, the identified features were compared with other IL-10 sequences. The gene expressions in healthy and challenged (Vibrio harveyi) fish were studied.
The sequence analysis showed an open reading frame of 564 bp and a 3' UTR (untranslated region) of 217 bp. The phylogram revealed an evolutionary distinction between marine and freshwater teleost IL-10. The shorter 3' UTR, additional conserved cysteines capable of forming stable disulphide bonds, and lesser mRNA instability moieties suggest the better structural stability of teleost IL-10 than tetrapods. Results identified 60 miRNA-mRNA duplexes that can regulate IL-10 3' UTR. Nine identified miRNAs are involved in immune response and seven are expressed in macrophages. The gills showed the highest gene expression in healthy fish. The study discovered two IL-10 mRNA transcripts that differed in 5' UTR lengths and thermodynamic ensemble's free energy. There was an increased expression of both tbil-10-mRNA transcripts from 2 to 48 h post-challenge which peaked at 24 h after the challenge, with higher expression of short mRNA transcript.
The results gave insights into the structural, functional, post-transcriptional regulatory mechanisms, and expression characteristics of the IL-10 gene in T. blochii.
白细胞介素10（IL-10）在硬骨鱼的免疫调节中具有独特地位。改变IL-10途径会改变硬骨鱼的疾病易感性；然而，目前尚无关于其转录后调控的数据。卵形鲳鲹是一种高价值的海水养殖品种。
通过cDNA末端快速扩增-PCR（Rapid Amplification of cDNA Ends-PCR）获得全长tbil-10基因。在进行详细的序列分析后，将鉴定出的特征与其他IL-10序列进行比较。研究了健康鱼和受攻击（哈维氏弧菌感染）鱼中的基因表达情况。
序列分析显示开放阅读框为564 bp，3'非翻译区（UTR）为217 bp。系统发育树显示海水和淡水硬骨鱼的IL-10在进化上存在差异。较短的3'UTR、能够形成稳定二硫键的额外保守半胱氨酸以及较少的mRNA不稳定部分表明，硬骨鱼IL-10的结构稳定性优于四足动物。结果鉴定出60个可调节IL-10 3'UTR的miRNA-mRNA双链体。鉴定出的9个miRNA参与免疫反应，7个在巨噬细胞中表达。鳃在健康鱼中显示出最高的基因表达。该研究发现了两种在5'UTR长度和热力学系综自由能上存在差异的IL-10 mRNA转录本。攻击后2至48小时，两种tbil-10-mRNA转录本的表达均增加，在攻击后24小时达到峰值，短mRNA转录本的表达更高。
这些结果为卵形鲳鲹中IL-10基因的结构、功能、转录后调控机制及表达特征提供了见解。
