Supplementary Materials for: Homeostatic adaptations of the amphibious fish Polypterus in terrestrial environments

This dataset contains supplementary tables and figures associated with the manuscript: "Homeostatic adaptations of the amphibious fish Polypterus in terrestrial environments." Table S1. Body size measurements (total length and body weight) and experimental use for each Polypterus senegalus individual used in this study. Table S2. Nucleotide sequences of split oligo probes used for in situ HCR (hybridization chain reaction). Table S3. Nucleotide sequences of primers used for RT-PCR analysis of tissue distribution. Table S4. GenBank accession numbers of glutamine synthetase (gs) mRNA sequences used for the phylogenetic analysis (Fig. 6B). Figure S1. Tissue distribution of scnn1a, gr, and mr mRNAs, and co-localization of scnn1a and gr in the kidney. A: RT-PCR analysis of scnn1a (ENaCα), gr (glucocorticoid receptor), mr (mineralocorticoid receptor), and gapdh (housekeeping control) mRNA expression across 13 tissues. scnn1a expression was detected exclusively in the kidney. gr was ubiquitously expressed across all tissues examined. mr expression was detected at markedly low levels. B: Representative confocal images of fluorescence in situ HCR for scnn1a (green) and gr (magenta) mRNAs in kidney cryosections. gr was broadly expressed in tubule cells and co-expressed with scnn1a-positive distal tubule cells. Scale bar: 100 μm. Figure S2. Expression levels of RAAS-related and ENaC-regulatory genes in kidneys of Polypterus in aquatic and terrestrial conditions. A: Normalized expression levels of renin–angiotensin–aldosterone system (RAAS) components: renin (ren), angiotensinogen (agt), angiotensin-converting enzyme (ace and ace2), and angiotensin II receptor type 1a (agtr1a). B: Normalized expression levels of ENaC regulatory genes: serum- and glucocorticoid-regulated kinases (sgk1, sgk2a, sgk3) and NEDD4-like E3 ubiquitin protein ligase (nedd4l). None of the genes showed statistically significant differences between aquatic and terrestrial conditions (n.s., p ≥ 0.05). N = 6.