Fig. 1: Experimental groups and change of plasma angiotensin II level.

a Experimental workflow studying the camel SON (created using BioRender.com incorporating original material by the first author). After acclimatisation, hypothalamic samples were collected from 19 camels divided into 3 groups; control (water ad libitum, n = 5), WD (water deprivation for 20 days, n = 8) and rehydrated (water deprivation for 20 days followed by water ad libitum for three days, n = 6). A tissue block containing the SON was collected from the camel brain and further dissected to facilitate slicing. Coronal hypothalamic sections were prepared for RNAscope or collection of the SON samples (n = 5 for each condition) for RNAseq and/or qRT-PCR. For RNAseq, the population of RNA molecules were converted to cDNA for the next generation sequencing workflow. RNAseq data were analysed using software packages or online databases for quality control (QC), differential expression analysis, functional classification, and gene ontology analysis. The camel SON differentially expressed genes (DEGs) were compared to rat SON DEGs. Plasma ANG II levels during WD and following recovery by rehydration were measured. b Plasma ANG II over 20 days of WD compared to control. Data were analysed using two-way repeated measures ANOVA with Šídák’s multiple comparisons test. *padj ≤ 0.05, **padj ≤ 0.01, ****padj ≤ 0.0001 in relation to control. c Plasma ANG II over 72 h of rehydration (purple dots) for the rehydration camels (n = 6) in comparison to their control state (Day0, blue dot) and after 20 days of WD (Day20, red dot). Data were analysed using one-way mixed-effects model (restricted maximum likelihood) for repeated measures with Tukey’s multiple comparisons test. *padj ≤ 0.05, ***padj ≤ 0.001, ****padj ≤ 0.0001 in relation to control (Day0). ##padj ≤ 0.01 in relation to 20 days WD (Day20). +++padj ≤ 0.001, ++++padj ≤ 0.0001 in relation to 1 h rehydration.