Alkalinity is regarded as one of the primary stressors for aquatic animals in saline-alkaline water. Alternative splicing (AS) can significantly increase the diversity of transcripts and play key roles in stress response; however, the studies on AS under alkalinity stress of crustaceans are still limited. In the present study, we devoted ourselves to the study of AS under acute alkalinity stress at control (50 mg/L) and treatment groups (350 mg/L) by RNA-seq in pacific white shrimp (Litopenaeus vannamei). We identified a total of 10,556 AS events from 4865 genes and 619 differential AS (DAS) events from 519 DAS genes in pacific white shrimp. Functional annotation showed that the DAS genes primarily involved in spliceosome. Five splicing factors (SFs), U2AF1, PUF60, CHERP, SR140 and SRSF2 were significantly up-regulated and promoted AS. Furthermore, alkalinity activated the Leukocyte transendothelial migration, mTOR signaling pathway and AMPK signaling pathway, which regulated MAPK1, EIF3B and IGFP-RP1 associated with these pathways. We also studied three SFs (HSFP1, SRSF2 and NHE-RF1), which underwent AS to form different transcript isoforms. The above results demonstrated that AS was a regulatory mechanism in pacific white shrimp in response to acute alkalinity stress. SFs played vital roles in AS of pacific white shrimp, such as HSFP1, SRSF2 and NHE-RF1. DAS genes were significantly modified in immunity of pacific white shrimp to cope with alkalinity stress. This is the first study on the response of AS to acute alkalinity stress, which provided scientific basis for AS mechanism of crustaceans response to alkalinity stress.

碱度被认为是盐碱水中水生动物的主要应激源之一。选择性剪接（AS）可以显着增加转录本的多样性，在应激反应中发挥关键作用；然而，关于甲壳动物碱胁迫下AS的研究仍然有限。在本研究中，我们致力于通过RNA-seq研究凡纳滨对虾（Litopenaeus vannamei）在急性碱度胁迫下对照组（50 mg/L）和处理组（350 mg/L）的AS。我们在太平洋白虾中从 4865 个基因中总共鉴定出了 10,556 个 AS 事件，从 519 个 DAS 基因中鉴定出了 619 个差异 AS (DAS) 事件。功能注释表明DAS基因主要参与剪接体。五个剪接因子（SF）：U2AF1、PUF60、CHERP、SR140和SRSF2显着上调并促进AS。此外，碱度激活白细胞跨内皮迁移、mTOR信号通路和AMPK信号通路，调节与这些通路相关的MAPK1、EIF3B和IGFP-RP1 。我们还研究了三种 SF（HSFP1、SRSF2 和 NHE-RF1），它们经历 AS 形成不同的转录亚型。上述结果表明AS是太平洋白虾响应急性碱度胁迫的一种调节机制。SF在太平洋白虾AS中发挥着重要作用，如HSFP1、SRSF2和NHE-RF1。DAS基因在太平洋白虾应对碱度胁迫的免疫力中发生显着改变。这是首次研究AS对急性碱胁迫的响应，为甲壳动物响应碱胁迫的AS机制提供了科学依据。