Use of vivo-morpholinos for gene knockdown in the postnatal shark retina

Work in the catshark Scyliorhinus canicula has shown that the evolutionary origin of postnatal neurogenesis in vertebrates is earlier than previously thought. Thus, the catshark can serve as a model of interest to understand postnatal neurogenic processes and their evolution in vertebrates. One of the best characterized neurogenic niches of the catshark CNS is found in the peripheral region of the retina. Unfortunately, the lack of genetic tools in sharks limits the possibilities to deepen in the study of genes involved in the neurogenic process. Here, we report a method for gene knockdown in the juvenile catshark retina based on the use of Vivo-Morpholinos. To establish the method, we designed Vivo-Morpholinos against the proliferation marker PCNA. We first evaluated the possible toxicity of 3 different intraocular administration regimes. After this optimization step, we show that a single intraocular injection of the PCNA Vivo-Morpholino decreases the expression of PCNA in the peripheral retina, which leads to reduced mitotic activity in this region. This method will help in deciphering the role of other genes potentially involved in postnatal neurogenesis in this animal model.

Automated summary

Work in the catshark Scyliorhinus canicula reveals that postnatal neurogenesis in vertebrates originated earlier than previously assumed. This makes the catshark an interesting model for studying postnatal neurogenic processes and their evolution in vertebrates. However, the lack of genetic tools in sharks inhibits in-depth research on the genes involved in neurogenesis. In this study, the researchers developed a method using Vivo-Morpholinos to knock down genes in the catshark retina, specifically targeting the proliferation marker PCNA. The method was found to effectively reduce mitotic activity in the peripheral retina, providing a valuable tool for studying the role of other genes in postnatal neurogenesis in this animal model.