Flexible selection of diversified Na + /K + -ATPase α-subunit isoforms for osmoregulation in teleosts

摘要: Multiple Na+/K+-ATPase (NKA) α-subunit isoforms express differentially in response to salinity transfer teleosts but we observed that the isoform nomenclature is inconsistent with phylogenetic relationship of NKA α-genes. We cloned catalytic eels and medaka, analyzed time course their expressions osmoregulatory tissues after from freshwater (FW) seawater (SW), performed analyses deduce an evolutionary scenario illustrates how various duplication events have led current genomic arrangement α-genes teleosts. Five six α-subunits were medaka respectively. In eels, commonly-reported α1a α1b absent while α1c was diversified instead (α1c-1, α1c-2, α1c-3, α2, α3 eels). Phylogenetic estimation indicated salmon, tilapia, generated by independent thus they are paralogous isoforms. Re-examination expression changes known challenge revealed selected as predominant SW-types varied among teleost lineages. Diversification α1 occurred types gene duplication, or alternative transcription tandem genes form chimeric transcripts, there no trend for more copies euryhaline species. Our data suggest switching between FW (α1a predominates) SW (α1b occurs salmonids not universal Instead, α1c-1 major upregulated gill, intestine, kidney SW. Localization both mRNA protein showed consistent upregulation gill intestine renal distal collecting tubules, where low transcript levels accompanied high levels, suggesting a tissue-specific translational regulation determines fine-tunes expression. anterior most other less responsive changes. By integrating results, propose acclimation ancestrally selected, rather flexibly determined lineage-specific fashion