Characteristics of Shisa family genes in Zebrafish

Abstract

The Shisa family is a type of single-transmembrane adaptor proteins containing an N-terminal cysteine-rich domain and a proline-rich C-terminal region. Nine Shisa subfamily genes have been proposed in most vertebrates; however, some of them might be species-specific. The number of Shisa genes present in zebrafish remains unclear. The purpose of this study was to investigate the evolutionary relationships among Shisa family genes in zebrafish (TU strain) using phylogenetic and syntenic analyses. The function of shisa-2 was preliminarily examined via CRISPR/Cas13d-mediated knockdown. Following identification in zebrafish,10 Shisa family genes, namely shisa-1, 2, 3, 4, 5, 6, 7, 8, 9a, and 9b, were classified into three main clades and six subclades. Their encoding proteins contained a cysteine-rich N-terminal domain and a proline-rich C-terminal region containing different motifs. A specific syntenic block containing atp8a2 and shisa-2 was observed to be conserved across all species. Furthermore, all these genes were found to be expressed during embryogenesis. shisa-2 was expressed in the presomitic mesoderm, somites, and so on. shisa-2 was identified as a regulator of the expression of the somite formation marker mesp-ab. Overall, our study provides new insights into the evolution of Shisa family genes and the control of shisa-2 over the convergent extension cells of somatic precursors in zebrafish.