Differential expression patterns and developmental roles of duplicated scinderin-like genes in zebrafish.

Scinderin, the closest homologue of the actin-severing protein, gelsolin, has two similar paralogs (Scinla and Scinlb) in zebrafish. Scinla is abundant in the adult cornea; Scinlb comprises considerably less corneal protein. Here, we show that scinla is expressed in the nose, lens, brain, cornea and annular ligament of the iridocorneal angle; by contrast, scinlb is expressed in the hatching gland, floor plate, notochord, otic vesicle, brain, pharynx, cartilage, swim bladder and cornea. Activity of scinla and scinlb promoter fragments driving the EGFP reporter gene in transgenic zebrafish resembled scinla or scinlb expression. Previously, we showed that reduction of scinla by injection of antisense morpholino oligonucleotides ventralized embryos; here, specific reduction of scinlb expression led to subtle brain abnormalities associated with increased cell death, decreased shhb expression in the floor plate, and slightly reduced eye distance. Thus, scinla and scinlb have different expression patterns and developmental roles during zebrafish development.