Cyclin-dependent Kinase 1 (CDK1) in Pacific white shrimp (Litopenaeus vannamei): Molecular characterization and its role in response to cold stress

Cyclin-dependent kinases (CDKs) are a large family of proteins exerting different regulatory functions in eukaryotic cells, including control over the cell cycle and gene transcription. CDK1 controls the cell cycle and promotes cell proliferation by regulating the initiation and transition of the G2/M phase. Similar to mammals, CDK1 has also been characterized in arthropods; however, its functions and physiological importance in crus-taceans remain unknown. Our pervious transcriptomic data indicated that CDK1 was a candidate cold-stress response gene in the Pacific white shrimp (Litopenaeus vannamei). Therefore, in the present study, the full-length sequence of CDK1 (LvCDK1) was obtained from L. vannamei containing a conserved PSTAIRE sequence and ATP-binding region. The expression of LvCDK1 is tissue-specific, with relatively higher in the hepatopan-creas. The in situ hybridization (ISH) signals for LvCDK1 were present in the distal zone of hepatopancreas and mainly located in the cytoplasm and nucleus. The expression of LvCDK1 in hepatopancreatic was sensitive to environmental temperature. Furthermore, under cold stress, knockdown of LvCDK1 led to increased mortality in shrimp. Our study provides the first evidence of LvCDK1 responding to cold stress in shrimps. This mechanism for modifying the transcriptional roles of LvCDK1 may show new light on the molecular regulation of crustaceans in response to cold stress.