GENOMIC ANALYSIS OF THE <italic>ACSL</italic> GENE FAMILY IN THE <italic>GYMNOCYPRIS PRZEWALSKII</italic> AND ITS RESPONSE TO SALINE-ALKALI STRESS

This study delves into the significance of the long-chain acyl-CoA synthetase (<italic>ACSL</italic>) gene family in <italic>Gymnocypris przewalskii</italic> under saline-alkaline stress, conducting bioinformatics analysis on the genome date and exploring saline-alkaline responses through gene expression detection. The results showed that nine <italic>ACSL</italic> gene family members encoding proteins ranging from 640 to 834 amino acids. Despite notable differences in gene structure, motif and domain analysis showcased a high level of conservation among these members. Chromosome mapping revealed the dispersion of <italic>ACSL</italic> gene family members across nine chromosomes (Chr8, 13, 15, 40, 41, 48, 64, 82, and 87), all encoding hydrophilic properties. Except for <italic>ACSL2</italic> and <italic>ACSL3a</italic>, the rest are stable proteins. The product of <italic>ACSL4b</italic> is an acidic protein, while all others are basic. Subcellular localization prediction results indicated that <italic>ACSL2</italic> is localized to the cytoplasm, <italic>ACSL3a</italic>, <italic>ACSL3b</italic>, <italic>ACSL4a</italic>, and <italic>ACSL4b</italic> to the peroxisome, and the rest to the cell membrane. qRT-PCR analysis revealed tissue-specific expression patterns of <italic>ACSL</italic> genes in <italic>Gymnocypris przewalskii</italic>, with <italic>ACSL3b, ACSL4b</italic>, and <italic>ACSL5</italic> being highly expressed in the kidney, while <italic>ACSL3a</italic>, <italic>ACSL4a</italic>, and <italic>ACSL5</italic> exhibited elevated expression in the intestine. Under saline-alkali stress, high level expression of <italic>ACSL2, ACSL3a</italic>, and <italic>ACSL6</italic> was detected in the gill, and transcription of <italic>ACSL1a, ACSL2, ACSL3a</italic>, and <italic>ACSL5</italic> were markedly up-regulated in the kidney. In the intestine, expressions of <italic>ACSL3b</italic> and <italic>ACSL6</italic> were prominently up-regulated. These findings highlight the <italic>ACSL</italic> gene family in <italic>Gymnocypris przewalskii</italic> contributes to multiple physiological functions under saline-alkaline stress, including energy supply through lipid metabolism, maintenance of osmotic balance, and immune regulation.