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Lanza DG, Gaspero A, Lorenzo I, Liao L, Zheng P, Wang Y, Deng Y, Cheng C, Zhang C, Seavitt JR, DeMayo FJ, Xu J, Dickinson ME, Beaudet AL, Heaney JD. Comparative analysis of single-stranded DNA donors to generate conditional null mouse alleles. BMC Biol 2018; 16:69. [PMID: 29925370 PMCID: PMC6011517 DOI: 10.1186/s12915-018-0529-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 05/09/2018] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND The International Mouse Phenotyping Consortium is generating null allele mice for every protein-coding gene in the genome and characterizing these mice to identify gene-phenotype associations. While CRISPR/Cas9-mediated null allele production in mice is highly efficient, generation of conditional alleles has proven to be more difficult. To test the feasibility of using CRISPR/Cas9 gene editing to generate conditional knockout mice for this large-scale resource, we employed Cas9-initiated homology-driven repair (HDR) with short and long single stranded oligodeoxynucleotides (ssODNs and lssDNAs). RESULTS Using pairs of single guide RNAs and short ssODNs to introduce loxP sites around a critical exon or exons, we obtained putative conditional allele founder mice, harboring both loxP sites, for 23 out of 30 targeted genes. LoxP sites integrated in cis in at least one mouse for 18 of 23 genes. However, loxP sites were mutagenized in 4 of the 18 in cis lines. HDR efficiency correlated with Cas9 cutting efficiency but was minimally influenced by ssODN homology arm symmetry. By contrast, using pairs of guides and single lssDNAs to introduce loxP-flanked exons, conditional allele founders were generated for all four genes targeted, although one founder was found to harbor undesired mutations within the lssDNA sequence interval. Importantly, when employing either ssODNs or lssDNAs, random integration events were detected. CONCLUSIONS Our studies demonstrate that Cas9-mediated HDR with pairs of ssODNs can generate conditional null alleles at many loci, but reveal inefficiencies when applied at scale. In contrast, lssDNAs are amenable to high-throughput production of conditional alleles when they can be employed. Regardless of the single-stranded donor utilized, it is essential to screen for sequence errors at sites of HDR and random insertion of donor sequences into the genome.
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Affiliation(s)
- Denise G Lanza
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, 77030, USA
- Mouse ES Cell Core, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Angelina Gaspero
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, 77030, USA
| | - Isabel Lorenzo
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, 77030, USA
- Mouse ES Cell Core, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Lan Liao
- Department of Molecular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
- Genetically Engineered Mouse Core, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Ping Zheng
- Mouse ES Cell Core, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Ying Wang
- Mouse ES Cell Core, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Yu Deng
- Lester and Sue Smith Breast Center, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Chonghui Cheng
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, 77030, USA
- Department of Molecular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
- Lester and Sue Smith Breast Center, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Chuansheng Zhang
- Department of Neuroscience, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - John R Seavitt
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, 77030, USA
| | - Francesco J DeMayo
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, Durham, NC, 27709, USA
| | - Jianming Xu
- Department of Molecular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
- Genetically Engineered Mouse Core, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Mary E Dickinson
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Arthur L Beaudet
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, 77030, USA
| | - Jason D Heaney
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, MS BCM225, Houston, TX, 77030, USA.
- Mouse ES Cell Core, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA.
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Turchetto J, Sequeira AF, Ramond L, Peysson F, Brás JLA, Saez NJ, Duhoo Y, Blémont M, Guerreiro CIPD, Quinton L, De Pauw E, Gilles N, Darbon H, Fontes CMGA, Vincentelli R. High-throughput expression of animal venom toxins in Escherichia coli to generate a large library of oxidized disulphide-reticulated peptides for drug discovery. Microb Cell Fact 2017; 16:6. [PMID: 28095880 PMCID: PMC5242012 DOI: 10.1186/s12934-016-0617-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 12/16/2016] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Animal venoms are complex molecular cocktails containing a wide range of biologically active disulphide-reticulated peptides that target, with high selectivity and efficacy, a variety of membrane receptors. Disulphide-reticulated peptides have evolved to display improved specificity, low immunogenicity and to show much higher resistance to degradation than linear peptides. These properties make venom peptides attractive candidates for drug development. However, recombinant expression of reticulated peptides containing disulphide bonds is challenging, especially when associated with the production of large libraries of bioactive molecules for drug screening. To date, as an alternative to artificial synthetic chemical libraries, no comprehensive recombinant libraries of natural venom peptides are accessible for high-throughput screening to identify novel therapeutics. RESULTS In the accompanying paper an efficient system for the expression and purification of oxidized disulphide-reticulated venom peptides in Escherichia coli is described. Here we report the development of a high-throughput automated platform, that could be adapted to the production of other families, to generate the largest ever library of recombinant venom peptides. The peptides were produced in the periplasm of E. coli using redox-active DsbC as a fusion tag, thus allowing the efficient formation of correctly folded disulphide bridges. TEV protease was used to remove fusion tags and recover the animal venom peptides in the native state. Globally, within nine months, out of a total of 4992 synthetic genes encoding a representative diversity of venom peptides, a library containing 2736 recombinant disulphide-reticulated peptides was generated. The data revealed that the animal venom peptides produced in the bacterial host were natively folded and, thus, are putatively biologically active. CONCLUSIONS Overall this study reveals that high-throughput expression of animal venom peptides in E. coli can generate large libraries of recombinant disulphide-reticulated peptides of remarkable interest for drug discovery programs.
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Affiliation(s)
- Jeremy Turchetto
- Unité Mixte de Recherche (UMR) 7257, Centre National de la Recherche Scientifique (CNRS) Aix-Marseille Université, Architecture et Fonction des Macromolécules Biologiques (AFMB), Marseille, France
| | - Ana Filipa Sequeira
- CIISA-Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal
- NZYtech Genes & Enzymes, Campus do Lumiar, Estrada do paço do Lumiar, 1649-038 Lisbon, Portugal
| | - Laurie Ramond
- Unité Mixte de Recherche (UMR) 7257, Centre National de la Recherche Scientifique (CNRS) Aix-Marseille Université, Architecture et Fonction des Macromolécules Biologiques (AFMB), Marseille, France
| | - Fanny Peysson
- Unité Mixte de Recherche (UMR) 7257, Centre National de la Recherche Scientifique (CNRS) Aix-Marseille Université, Architecture et Fonction des Macromolécules Biologiques (AFMB), Marseille, France
| | - Joana L. A. Brás
- NZYtech Genes & Enzymes, Campus do Lumiar, Estrada do paço do Lumiar, 1649-038 Lisbon, Portugal
| | - Natalie J. Saez
- Unité Mixte de Recherche (UMR) 7257, Centre National de la Recherche Scientifique (CNRS) Aix-Marseille Université, Architecture et Fonction des Macromolécules Biologiques (AFMB), Marseille, France
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, 4072 Australia
| | - Yoan Duhoo
- Unité Mixte de Recherche (UMR) 7257, Centre National de la Recherche Scientifique (CNRS) Aix-Marseille Université, Architecture et Fonction des Macromolécules Biologiques (AFMB), Marseille, France
| | - Marilyne Blémont
- Unité Mixte de Recherche (UMR) 7257, Centre National de la Recherche Scientifique (CNRS) Aix-Marseille Université, Architecture et Fonction des Macromolécules Biologiques (AFMB), Marseille, France
| | | | - Loic Quinton
- Mass Spectrometry Laboratory, B6c University of Liège, MolSys-Quartier Agora, Allée du six Aout 11, 4000 Liège, Belgium
| | - Edwin De Pauw
- Mass Spectrometry Laboratory, B6c University of Liège, MolSys-Quartier Agora, Allée du six Aout 11, 4000 Liège, Belgium
| | - Nicolas Gilles
- CEA/DRF/iBiTecS, Service d’Ingénierie Moléculaire des Protéines, 91191 Gif-sur-Yvette, France
| | - Hervé Darbon
- Unité Mixte de Recherche (UMR) 7257, Centre National de la Recherche Scientifique (CNRS) Aix-Marseille Université, Architecture et Fonction des Macromolécules Biologiques (AFMB), Marseille, France
| | - Carlos M. G. A. Fontes
- CIISA-Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal
- NZYtech Genes & Enzymes, Campus do Lumiar, Estrada do paço do Lumiar, 1649-038 Lisbon, Portugal
| | - Renaud Vincentelli
- Unité Mixte de Recherche (UMR) 7257, Centre National de la Recherche Scientifique (CNRS) Aix-Marseille Université, Architecture et Fonction des Macromolécules Biologiques (AFMB), Marseille, France
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