Genes differentially expressed between ecotypes (comp 3 and 4)
In contrast 3 we only discuss differences between the two controls (Figure 2). Genes that were upregulated in SwC compared to FwC included the Sarcoplasmic/endoplasmic reticulum calcium ATPase 1 (ATP2a1 ), an enzyme that catalyzes the hydrolysis of ATP with the translocation of calcium from the cytosol to the sarcoplasmic reticulum lumen; several stress-related cytochrome P450 (CYP1a (also overlapping with contrast 1 and 2), CYP1c1, CYP1c2, CYP2y3, CYP7a1 ), seven genes in the solute carrier family (including SLC16a1b ), one myosin (myh11a ), where the class XI myosins are associated with various organelles/vesicles (Tian et al. 2021). Genes upregulated in FwC compared to SwC included Aquaporin 3a (AQ P3a), several ATP’s (ATP6V0C, ATP6V0C, ATP6v1d, AP6v1e1b ; Figure 7 ), arrestin domain containing 2 (arrdc2 ), 11 solute carriers, and prolactin Receptor type a (PRLRa ) had a higher expression in freshwater, and a slight regulation within saltwater, as SwFw had lower expression than SwC (Figure 6c) .
Of the 502 apparently transcripts that had similar expression within ecotype despite salinity change, 173 had a higher expression in the saltwater ecotype, and included one gene linked to ATP-transport, ATPase phospholipid transporting (ATP8a2 ), two linked to calcium transport; calcium channel, voltage-dependent (cacnb1 ,Figure 6d ) and anoctamin 1, calcium activated chloride channel (ano1 , Figure 6b ), NADPH oxidase 1 (nox1 ), one solute carriers (SLC6a1like ), interleukin 11 receptor (IL11ra ) and genes linked to tyrosine kinase proteins, which in turn has been found to function as activators of several ion-pumps; protein kinase 7 (PTK7 ), protein tyrosine phosphatase- non-receptor (PTPN14 ) and receptor type (PTPrfa ), and erb-b2 receptor tyrosine kinase 3b (erbb3b ). A total of 329 transcripts had a higher expression in the freshwater ecotype, and included several ATP’s (ATP6V0e1, ATP6V1A, ATP6V1c1a, ATP6V1f ,Figure 7 ), where one is involved in T-cell regulation (tcirg1a ); four annexin genes, which are linked to salinity stress in plants (ANXAa1, ANXA3b, ANXA5b (Figure 6d ) andANXA11b ), two linked to calcium: calcium homeostasis modulator family (calhm5.2 ) and mitochondrial calcium uptake (micu2 ) and one stress-related UDP-glucose (ugp2b ). The freshwater ecotype also had a higher expression of claudins (cldn1, cldn7b, cldnf) and occludins (oclnb ), proteins that are involved with tight junctions and reduction of ion efflux from the cells.