- The ferlin protein family regulates membrane trafficking events for a wide range of cellular and physiological processes in eukaryotic organisms. Structurally, ferlins are distinguished by containing five to seven C2 domains with a single-pass transmembrane domain at the C-terminus. In mammals, there are 6 ferlin genes, including Fer1L6, which confer calcium sensitivity to a diverse range of vesicle fusion and fission events. To determine the role of Fer1L6 in vertebrates, Fer1L6 mRNA levels were analyzed in zebrafish. Analysis revealed the presence of transcripts in all organs of developing larvae, with expression in adults restricted to gill and gonads. Further, a Fer1L6 mutant zebrafish line displayed distorted striated muscle and abnormal development of the heart. To characterize the function of the C2 domains of Fer1L6, expression vectors containing sequences for the domains of the protein were constructed. This data will further our understanding of how Fer1L6 contributes to vertebrate muscle development and will eventually lead to predictions of relevance in human health.