We have used whole-mount in situ hybridization to analyze Na,K-ATPase α and β subunit gene expression in the developing zebrafish ear. Four α1-like (α1a.1, α1a.2, α1a.4, and α1a.5) and two β (β1a and β2b) subunit genes are expressed in ear beginning at mid-somitogenesis. Each gene exhibits a distinct spatial and temporal expression pattern. The α1a.1 gene was ubiquitously expressed in the otic epithelium from mid-somitogenesis to 24 hr postfertilization (hpf). Expression of this gene was gradually reduced and by 48 hpf, α1a.1 transcripts were no longer detectable in the ear. The α1a.2 and α1a.5 genes were expressed in regions that correspond to the anterior macula, lateral crista, and semicircular canal projections up to 48 hpf. At later stages, expression of these genes was limited to cells in the dorsolateral septum and semicircular canal projections. α1a.4 and β1a transcripts were ubiquitously expressed during ear development and were present in most otic tissues at 5 days postfertilization (dpf). Expression of the β2b gene, on the other hand, was restricted to subsets of cells that form sensory epithelia. These results strongly suggest different functional roles for individual Na,K-ATPase genes in zebrafish ear development. Na,K-ATPase genes are likely to represent useful markers for the analysis of zebrafish otogenesis.
All Science Journal Classification (ASJC) codes
- Developmental Biology