Differential expression of synapsin genes during early zebrafish development

Synapsins are a family of synaptic vesicle (SV)-associated phosphoproteins that have been identified in several vertebrates and invertebrates. We report here the cloning and expression of synapsin family genes in the zebrafish Danio rerio. We identified the complete coding sequence of synapsin 3, which is not present in the currently available genome, and characterized and annotated the synapsin gene family in the zebrafish D. rerio. By means of whole-mount in situ hybridization, we showed the spatiotemporal expression of synapsin genes at three different time points during early embryonic development: 20-24 h postfertilization (hpf), 30-33 hpf, and 3 days postfertilization (dpf). As very few data are available describing the expression of synapsin family genes during CNS development in vertebrate models, our results may help to achieve a better understanding of the complex functions of these molecules. Finally, new interesting evidence from our temporal gene expression studies suggests that synapsins have also maternal functions.