Salinity represents a critical environmental factor for fishes, and it can directly influence their survival. Transcriptomic analysis at the gene expression level has been extensively conducted to identify functional genes or pathways involved in salinity adaptation in numerous euryhaline fishes. However, the post-transcriptional regulation mechanism in response to salinity changes remains largely unknown. Alternative splicing (AS), the main mechanism accounting for the complexity of the transcriptome and proteome in eukaryotes, plays essential roles in determining organismal responses to environmental changes. In this study, RNA-Seq datasets were used to examine the AS profiles in spotted sea bass (Lateolabrax maculatus), a typical euryhaline fish species. The results showed that 8618 AS events were identified in spotted sea bass. Furthermore, a total of 501 and 162 differential alternative splicing (DAS) events were characterized in the gill and liver under low- and high-salinity environments, respectively. Based on GO enrichment results, DAS genes in both the gill and liver were commonly enriched in 8 GO terms, and their biological functions were implicated in many stages of gene expression regulation, including transcriptional regulation and post-transcriptional regulation. Sanger sequencing and qPCR validations provided additional evidence to ensure the accuracy and reliability of our bioinformatic results. This is the first comprehensive view of AS in response to salinity changes in fish species, providing insights into the post-regulatory molecular mechanisms of euryhaline fishes in salinity adaptation.

中文翻译：

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选择性剪接（AS）机制在斑点鲈鱼中响应不同盐度环境起着重要作用。

盐度是鱼类的关键环境因素，它可以直接影响鱼类的生存。在基因表达水平上的转录组学分析已被广泛进行，以鉴定与许多淡碱性鱼的盐度适应有关的功能性基因或途径。然而，响应盐度变化的转录后调控机制仍然未知。替代剪接（AS）是解决真核生物转录组和蛋白质组复杂性的主要机制，在确定机体对环境变化的反应中起着至关重要的作用。在这项研究中，RNA-Seq数据集用于检查斑纹鲈鱼（Lateolabrax maculatus）（一种典型的淡滨鱼）的AS谱。结果表明，在斑点鲈鱼中鉴定出8618例AS事件。此外，在低盐度和高盐度环境下，g和肝脏中分别表征了总共501和162个差异性可变剪接（DAS）事件。根据GO富集的结果，D和肝脏中的DAS基因通常在8个GO项中富集，其生物学功能涉及基因表达调控的许多阶段，包括转录调控和转录后调控。Sanger测序和qPCR验证为确保我们生物信息学结果的准确性和可靠性提供了更多证据。这是AS对鱼类盐度变化的响应的第一个综合观点，为洞察盐碱鱼类适应盐度的后调控分子机制提供了见识。