Genetically modified mice by means of homologous recombination are generated by injection of manipulated ES cells into recipient blastocysts. The injected blastocysts, following re-introduction into recipient foster mothers will produce chimeric mice in which the manipulated ES clones populate the germ line and transmit the desired mutation to the offspring. The technology to generate genetically modified chimeras involves 3 main sequential steps. 1- Engineering of the targeting vector to introduce the desired mutation into the mouse genome; 2- Introduction of the targeting vector into mouse embryonic stem cells (ES cells) to accomplish homologous recombination; 3- Injection with the targeted ES cells and immediate transfer of blastocysts into pseudo-pregnant recipient mothers. We provide diversified support to the CCR-NCI scientific community with counseling and technical help for all 3 different stages depending on the experience and needs of the investigator. 1-Engineering of the targeting vector. The generation of a targeting vector for homologous recombination in ES cells requires careful planning. It is of paramount importance for the overall success of a specific project that this step is well thought and planned. We provide scientific input for the designing of an optimal targeting vector. We make available to the investigators the best molecular tools to engineer the targeting vector including protocols and reagents for the use of the recombineering technology. Recombineering is a powerful tool that allows the generation of the desired DNA vectors in a relatively short period of time (Copeland NG, Jenkins NA, Court DL. Recombineering: a powerful new tool for mouse functional genomics. Nat Rev Genet. 2001, 769-79). 2- Introduction of the targeting vector into the ES cells to accomplish homologous recombination. The targeting vector is introduced into mouse ES cells by electroporation. ES clones are positively selected for the presence of specific antibiotic resistance (for example neomycin, but also puromycin or blastycidin) and negatively by the presence of the Thymidine Kinase (TK) or Diphteria Toxin (DT) genes. Selected clones are then grown in duplicate and one set is given to the investigators for analysis of specific homologous recombination. 3- Injection of the targeted ES cells into mouse blastocysts and subsequent transfer into pseudo-pregnant recipient females. ES clones identified as correctly targeted are grown and expanded for the micro-injection into blastocysts at 3.5 days of gestation. The microinjected blastocysts are implanted into pseudo-pregnant recipient females who will generate chimeras derived from the blastocyst and the targeted ES clone. Coat color is used to score and identify the chimeras that will likely transmit the desired mutation to the progeny. As indicated above we have also started working with the CRISPR/Cas9 technology, the new evolution of creating targeted mutations in mice. With the CRISPR/Cas9 technology mutations can be introduced into a single gene or multiple genes at the same time by injecting different guide RNAs into the cytoplasm. The enzyme Cas9 uses the guide RNA to zero in on target DNA, then edits the DNA to disrupt genes or insert a desired sequence. CRISPR/Cas9 technology is a way to accelerate the generation of targeted mutation mouse models and it is a more efficient and a less costly procedure than the traditional ES cell-based targeted mutagenesis.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Scientific Cores Intramural Research (ZIC)
Project #
1ZICBC011265-09
Application #
9780241
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
9
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Basic Sciences
Department
Type
DUNS #
City
State
Country
Zip Code
Chen, Keqiang; Tang, Peng; Bao, Zhiyao et al. (2018) Deficiency in Fpr2 results in reduced numbers of Lin-cKit+Sca1+ myeloid progenitor cells. J Biol Chem 293:13452-13463
Windpassinger, Christian; Piard, Juliette; Bonnard, Carine et al. (2017) CDK10 Mutations in Humans and Mice Cause Severe Growth Retardation, Spine Malformations, and Developmental Delays. Am J Hum Genet 101:391-403
Xiong, Yulan; Neifert, Stewart; Karuppagounder, Senthilkumar S et al. (2017) Overexpression of Parkinson's Disease-Associated Mutation LRRK2 G2019S in Mouse Forebrain Induces Behavioral Deficits and ?-Synuclein Pathology. eNeuro 4:
Casoni, Filippo; Croci, Laura; Bosone, Camilla et al. (2017) Zfp423/ZNF423 regulates cell cycle progression, the mode of cell division and the DNA-damage response in Purkinje neuron progenitors. Development 144:3686-3697
Seaman, Steven; Zhu, Zhongyu; Saha, Saurabh et al. (2017) Eradication of Tumors through Simultaneous Ablation of CD276/B7-H3-Positive Tumor Cells and Tumor Vasculature. Cancer Cell 31:501-515.e8
Gopinathan, Lakshmi; Szmyd, Radoslaw; Low, Diana et al. (2017) Emi2 Is Essential for Mouse Spermatogenesis. Cell Rep 20:697-708
Tsai, Yien Che; Kotiya, Archana; Kiris, Erkan et al. (2017) Deubiquitinating enzyme VCIP135 dictates the duration of botulinum neurotoxin type A intoxication. Proc Natl Acad Sci U S A 114:E5158-E5166
Kieffer-Kwon, Kyong-Rim; Nimura, Keisuke; Rao, Suhas S P et al. (2017) Myc Regulates Chromatin Decompaction and Nuclear Architecture during B Cell Activation. Mol Cell 67:566-578.e10
Tu, Zhaowei; Bayazit, Mustafa Bilal; Liu, Hongbin et al. (2017) Speedy A-Cdk2 binding mediates initial telomere-nuclear envelope attachment during meiotic prophase I independent of Cdk2 activation. Proc Natl Acad Sci U S A 114:592-597
Tobe, Ryuta; Carlson, Bradley A; Huh, Jang Hoe et al. (2016) Selenophosphate synthetase 1 is an essential protein with roles in regulation of redox homoeostasis in mammals. Biochem J 473:2141-54

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