Genome-wide identification of the NHE gene family in Coilia nasus and its response to salinity challenge and ammonia stress

Abstract

Background In aquatic environments, pH, salinity, and ammonia concentration are extremely important for aquatic animals. NHE is a two-way ion exchange carrier protein, which can transport Na+ into cells and exchange out H+, and also plays key roles in regulating intracellular pH, osmotic pressure, and ammonia concentration. Results In the present study, ten NHEs, the entire NHE gene family, were identified from Coilia nasus genome and systemically analyzed via phylogenetic, structural, and synteny analysis. Different expression patterns of C. nasus NHEs in multiple tissues indicated that expression profiles of NHE genes displayed tissue-specific. Expression patterns of C. nasus NHEs were related to ammonia excretion during multiple embryonic development stages. To explore the potential functions on salinity challenge and ammonia stress, expression levels of ten NHEs were detected in C. nasus gills under hypotonic stress, hypertonic stress, and ammonia stress. Expression levels of all NHEs were upregulated during hypotonic stress, while they were downregulated during hypertonic stress. NHE2 and NHE3 displayed higher expression levels in C. nasus larvae and juvenile gills under ammonia stress. Conclusions Our study revealed that NHE genes played distinct roles in embryonic development, salinity stress, and ammonia exposure. Syntenic analysis showed significant difference between stenohaline fish and euryhaline fishes. Our findings will provide insight into effects of C. nasus NHE gene family on ion transport and ammonia tolerance and be beneficial for healthy aquaculture of C. nasus.

Genome−wide expression profile analysis of the NHE and NKA gene family in Rachycentron canadum (Linnaeus, 1766) and its response to salinity adaptation

“…These genes were found to be distributed randomly on 10 and 9 superscaffolds, respectively, which is consistent with the findings reported by Zhang et al (2019). The gene sequences of NHE and NKA gene family members were compared with those of O. mykiss, L. japonicus and S. maximus to name them and analyze the conserved motifs and structural domain characteristics (Berthelot et al, 2014;Figueras et al, 2016;Gao et al, 2022). The results revealed that the motifs and domains of the NHE genes were concentrated in the Na + /H + exchanger domains, which the identification of the NKA also showed that they closely association with Cation transporter/ATPase and Hydrolase domains, and the motifs and domains of different members were arranged in different patterns.…”