RNA-binding motif protein RBM22 is required for normal development of zebrafish embryos

RBM22 is a newly discovered RNA-binding motif protein, belonging to the SLT11 family; it has been reported to be involved in pre-splicesome assembly and to interact with the Ca(2+) -signaling protein ALG-2. However, previous studies have not demonstrated whether its expression is essential for early embryogenesis in vertebrates. We utilized zebrafish as a developmental model to study the role of RBM22 during embryogenesis. The aligned protein sequences of RBM22 were found to be highly conserved. In situ analysis showed that zRBM22 was expressed as early as the one-cell stage, implying maternal origin during oogenesis; embryos continued to express zRBM22 through at least the 32-h post-fertilization (hpf) stage of development. RT-PCR analysis confirmed the in situ expression pattern, indicating that RBM22 is expressed without any spatial and temporal specificity during zebrafish development. zRBM22 morpholino-induced alterations in development were observed as early as 15 hpf of embryogenesis, based on a morphological analysis. Embryogenesis was monitored through 32 hpf; knockdown resulted in a truncated axis and developmental arrest of the head and tail. We conclude that RBM22 plays an important role in zebrafish embryogenesis.