Genomics and Applied Biology 2024, Vol.15, No.2, 99-106 http://bioscipublisher.com/index.php/gab 103 Figure 2 Schematic representation of the target site and the surrounding genome in chromosome 1 of channel catfish (Ictalurus punctatus) genome where insertion of the transgene was made (Adopted from Simora et al., 2020) Image caption: The 20-bp guide RNA sequence containing the PAM was shown and the cut site (red arrow) which aided the targeted insertion of the donor DNA constructs: double-stranded DNA (dsDNA) driven by zebrafish ubiquitin promoter (dsDNA-UBI-Cath), dsDNA driven by carp β-actin promoter (dsDNA-BA-Cath) and plasmid DNA, pUCIDT with zebrafish ubiquitin promoter (plasmid-UBI-Cath). Grik2 is 1 376 bp upstream of the target and hace1 is 295 702 bp downstream of the target (Adopted from Simora et al., 2020) 5 Environmental and Regulatory Considerations 5.1 Ecological implications of gene editing in aquatic species The application of CRISPR-Cas9 in tilapia and other aquatic species holds significant promise for enhancing growth rates and disease resistance. However, it also raises ecological concerns. Gene editing can lead to unintended side effects, such as genetic introgression into wild populations, which may disrupt local ecosystems and biodiversity (Gutási et al., 2023; Robinson et al., 2023). The potential for edited genes to spread to wild populations through escapees from aquaculture facilities is a critical issue that needs thorough investigation and mitigation strategies. Additionally, the ecological impacts of gene-edited tilapia must be assessed on a case-by-case basis to ensure that the benefits outweigh the potential risks to the environment (Robinson et al., 2023). 5.2 Risk assessment of genetically modified tilapia in aquatic ecosystems Risk assessment frameworks are essential for evaluating the safety and potential impacts of genetically modified tilapia in aquatic ecosystems. Current frameworks need to be adapted to address the unique challenges posed by CRISPR-Cas9 technology. These frameworks should incorporate considerations such as off-target effects, the stability of genetic modifications, and the potential for gene flow to wild populations (Okoli et al., 2021). Effective risk assessment must also include long-term ecological studies to monitor the impacts of gene-edited tilapia on local ecosystems and biodiversity (Roy et al., 2022; Robinson et al., 2023). Public and regulatory acceptance of genetically modified organisms (GMOs) in aquaculture will depend on the robustness of these risk assessments and the implementation of appropriate mitigation measures (Okoli et al., 2021). 5.3 Regulatory frameworks governing CRISPR-Cas9 in aquaculture The regulatory landscape for CRISPR-Cas9 applications in aquaculture is still evolving. Current regulations often do not fully address the specific challenges and opportunities presented by gene editing technologies. For instance, the regulatory status of CRISPR-edited fish, such as the FLT-01 Nile tilapia developed by AquaBounty, varies by region and is not always classified under traditional GMO regulations (Roy et al., 2022). There is a need for updated regulatory frameworks that can accommodate the rapid advancements in gene editing technologies while
RkJQdWJsaXNoZXIy MjQ4ODYzMg==