FLInt: single shot safe harbor transgene integration via Fluorescent Landmark Interference
Nawaphat Malaiwong1, Montserrat Porta-de-la-Riva, Michael Krieg
1Institut de Ciències Fotòniques (ICFO), 08860 Castelldefels, Spain.
G3 (Bethesda, Md.)
|February 22, 2023
Summary
Researchers developed a new CRISPR/Cas9 method for efficient transgene integration in Caenorhabditis elegans. This technique uses safe harbor loci and fluorescence markers for easy screening, overcoming common bioengineering bottlenecks.
Area of Science:
- Genetics
- Molecular Biology
- Bioengineering
Background:
- Stable transgene integration into the host genome is crucial for bioengineering but remains inefficient.
- Identifying transgenic organisms is challenging due to low success rates, necessitating improved screening methods.
- Safe and predictable DNA integration sites are needed to avoid interfering with host gene expression.
Purpose of the Study:
- To establish a versatile and efficient method for transgene integration in Caenorhabditis elegans.
- To utilize a library of safe harbor loci for predictable transgene insertion using CRISPR/Cas9.
- To develop a fluorescence-based screening system for identifying successful transgenesis.
Main Methods:
- Leveraged a library of approximately 300 fluorescent marker loci across all 6 Caenorhabditis elegans chromosomes as safe harbors.
- Employed CRISPR/Cas9 gene editing technology for targeted DNA cleavage and transgene integration.
- Utilized a single crRNA for efficient cleavage and integration, with loss of fluorescence indicating successful transgenesis.
Main Results:
- Demonstrated successful and stable integration of transgenes into the host genome at designated safe harbor loci.
- Showed that a single crRNA is sufficient for efficient targeted integration and screening via fluorescence loss.
- Confirmed that these loci can also serve as extrachromosomal landing sites and co-CRISPR markers without affecting animal phenotypes.
Conclusions:
- The developed CRISPR/Cas9-based method significantly improves the efficiency and predictability of transgene integration in Caenorhabditis elegans.
- Fluorescence interference serves as a facile screening mechanism, simplifying the identification of transgenic animals.
- The versatile safe harbor loci can be applied to various bioengineering strategies, including extrachromosomal applications and co-CRISPR marking, without adverse effects on organismal traits.
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