Genome-Wide Identification of Solute Carrier Family 12 and Functional Characterization of Its Role in Saline-Alkaline Stress Acclimation in the Ridgetail White Shrimp .

Solute carrier family 12 () encodes electroneutral cation-coupled chloride cotransporters responsible for transmembrane ion transport (Na, K, and Cl), which play a critical role in aquatic osmoregulation. However, the gene of () has not been systematically identified or functionally characterized. In this study, six genes were identified across the genome and classified into N(K)CC, KCC, CCC9, and CIP subfamilies. Three homologous genes (, , and ) were reported for the first time in crustaceans. The family exhibited distinct expression patterns in response to low-salinity, high-alkalinity, and saline-alkaline stress. was highly expressed in the gill, and its expression was closely correlated with saline-alkaline acclimation. Additionally, knockdown decreased survival under saline-alkaline stress. Thus, plays critical roles in osmotic regulation and saline-alkaline acclimation. This study provides crucial insights into 's saline-alkaline tolerance mechanisms, and the discovery of multiple homologs fills a gap in the crustacean gene family research.