淡水渔业2026，Vol.56Issue(1)：86-95,10.
不同水平多不饱和脂肪酸的鳙肌肉转录组分析
Transcriptome analysis of Hypophthalmichthys nobilis muscle at various polyunsaturated fatty acids levels
摘要
Abstract
As one of the four major Chinese carps,Hypophthalmichthys nobilis has a substantial market demand and relatively high nutritional value.Currently,traditional breeding methods are the predominant approaches for bighead carp breeding,which has a long history of progress in producing improved varieties.Besides growth rate and head size,the muscle quality is also an important trait of bighead carp.Creating novel germplasms with outstanding muscle quality is a new direction of bighead carp genetic breeding.Polyunsaturated fatty acids(PU-FAs)not only participate in the regulation of lipid metabolism in animals but also exert remarkable preventive and therapeutic effects on human diseases.The objective of this study is to conduct a transcriptomic analysis of bighead carp muscle tissues with various levels of PUFAs,aiming to identify key genes,regulatory pathways and single-nucleotide polymorphism(SNP)loci that may be involved in fatty acid synthesis and metabolism.The bighead carp samples used in this experiment were collected from Suzhou Future Aquaculture Farm.A total of 20 3-year-old individuals with an average body weight of(5.77±0.81)kg cultured under the same aquacul-ture conditions were randomly sampled.Dorsal muscle tissues were collected from these samples for fatty acid detection.Three fish with the highest PUFA levels,denoted as H1,H2 and H3,and three fish with the lowest PUFA levels,denoted as L1,L2,and L3,were selected for subsequent transcriptomic sequencing.The re-sults showed that the PUFA content of H1,H2,H3,L1,L2,and L3 was 54.633 mg/g,52.802 mg/g,52.464 mg/g,45.755 mg/g,46.902 mg/g,and 47.952 mg/g,respectively.More than 95.5%sequence fragments could be mapped to the genome.A total of 236 749 256 raw sequencing reads were obtained.After re-moving low-quality sequences and adapters,236 030 318 clean reads were obtained.The percentage of base quality values with Q20 was above 98%,and that of Q30 was above 94%,indicating that the quality of this transcriptome sequencing was good and that the sequencing data met the requirements for subsequent gene func-tional annotation and functional analysis.There were 266 279 SNP loci in the six samples.They were mainly concentrated in synonymous mutations(SNV)and nonsynonymous mutations(NSNV),with the numbers of 34 052 and 27 293,respectively.The mutations were mainly concentrated in the intronic,intergenic,exonic,and downstream regions of genes,and,among mutation types,base transitions outnumbered base transver-sions.Using|log2FC|>log2(1.5)and p-value<0.05 as criteria for significant differences,DESeq2 was used to analyse differential expression of the related genes.A total of 335 DEGs were identified between the high-PUFA and low-PUFA groups.Among them,the number of up-regulated genes in the high-PUFA group was 264,and the number of down-regulated genes was 71.The Gene Ontology(GO)enrichment analysis showed that the DEGs were predominantly enriched in three biological processes:Biological Process,Molecular Func-tion,and Cellular Component.Among these,the major enriched pathways encompassed the negative regulation of the response to stimulus,the negative regulation of signal transduction,and the negative regulation of cyste-ine-type endopeptidase activity involved in the apoptotic signalling pathway.Regarding the Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis of the DEGs,the major pathways were fatty acid biosyn-thesis,primary bile acid biosynthesis,glycerophospholipid metabolism,and glycerolipid metabolism.The key differentially expressed genes within the fatty acid biosynthesis pathway were identified as acacb and acsbg1.Nota-bly,42 SNP loci were found to be linked to the key gene acacb,exhibiting a significant association with fatty acid synthesis.Additionally,this study revealed that lpin1 and acsbg1 might be implicated in fatty acid synthesis,thus needing further investigation.To validate the accuracy of the sequencing results,ten DEGs were randomly selected from each enriched pathway for quantitative real-time polymerase chain reaction(qRT-PCR)verifica-tion.The qRT-PCR results were largely consistent with the trends observed in the transcriptomic sequencing re-sults,thereby indicating the reliability of the present transcriptomic sequencing.These findings are expected to provide support for the selective breeding of novel germplasms of H.nobilis with a high content of PUFAs in the muscle.关键词
鳙(Hypophthalmichthys nobilis)/多不饱和脂肪酸/转录组/差异表达基因Key words
Hypophthamichthys nobilis/poly-unsaturated fatty acids/transcriptome/DEGs分类
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沈晓桔,王兰梅,朱文彬,傅建军,罗明坤,邓玉婕,杨皓然,董在杰..不同水平多不饱和脂肪酸的鳙肌肉转录组分析[J].淡水渔业,2026,56(1):86-95,10.基金项目
国家大宗淡水鱼产业技术体系(CARS-45) （CARS-45）
