Since it was established in the early 1980s1 pronuclear injection of fertilised mouse zygotes is the most commonly used technique to generate genetically modified mice with a single integration site. Based on our published techniques2-3 we have successfully generated many mouse models of diseases4-6 and developed next generation inducible systems7. The injection of a transgene into fertilised mouse zygotes is a straightforward approach that allows the generation of mutant founders in as little as 6 weeks. We offer microinjection of your transgene of interest and subsequent identification of founder animals.
1) Gordon J.W., Scangos G.A., Plotkin D.J., Barbosa J.A., Ruddle F.H. (1980). Genetic transformation of mouse embryos by microinjection of purified DNA. Proceedings of the National Academy of Sciences of the United States of America Dec;77(12):7380-4.
2) Ittner L.M., Götz J. (2007). Pronuclear injection for the production of transgenic mice. Nature Protocols 2(5):1206-15.doi: 10.1038/nprot.2007.145
3) Delerue F., Ittner L.M. (2017) Generation of Genetically Modified Mice through the Microinjection of Oocytes. Journal of Visualized Experiments Jun 15;(124). doi: 10.3791/55765
4) Ittner L.M., Ke Y.D., Delerue F., Bi M., Gladbach A., van Eersel J., Wölfing H., Chieng B.C., Christie M.J., Napier I.A., Eckert A., Staufenbiel M., Hardeman E., Götz J. (2010). Dendritic function of tau mediates amyloid-beta toxicity in Alzheimer's disease mouse models. Cell Aug 6;142(3):387-97. doi: 10.1016/j.cell.2010.06.036.
5) Ittner A., Chua S.W., Bertz J., Volkerling A., van der Hoven J., Gladbach A., Przybyla M., Bi M., van Hummel A., Stevens C.H., Ippati S., Suh L.S., Macmillan A., Sutherland G., Kril J.J., Silva A.P., Mackay J.P., Poljak A., Delerue F., Ke Y.D., Ittner L.M. (2016). Site-specific phosphorylation of tau inhibits amyloid-β toxicity in Alzheimer's mice. Science Nov 18;354(6314):904-908.doi: 10.1126/science.aah6205
6) Ke Y.D., van Hummel A., Stevens C.H., Gladbach A., Ippati S., Bi M., Lee W.S., Krüger S., van der Hoven J., Volkerling A., Bongers A., Halliday G., Haass N.K., Kiernan M., Delerue F., Ittner L.M. (2015). Short-term suppression of A315T mutant human TDP-43 expression improves functional deficits in a novel inducible transgenic mouse model of FTLD-TDP and ALS. Acta Neuropathologica Nov;130(5):661-78. doi: 10.1007/s00401-015-1486-0
7) Delerue F., White M., Ittner L.M. (2014). Inducible, tightly regulated and non-leaky neuronal gene expression in mice. Transgenic Research. Apr;23(2):225-33. doi: 10.1007/s11248-013-9767-7.
During the last decade, the development of ES-Cell free methods for genomic modifications simplified and accelerated drastically the process of gene manipulation. The direct injection of nucleases into the one-cell embryos has repositioned microinjection at the forefront of genome editing, as it allows precise (targeted) manipulations of the mammalian genome. The first generation of these engineered endonucleases consisted of three types of protein-based molecular scissors: Zinc Finger Nucleases (ZFN), Transcription activator-like effector nucleases (TALEN), and Meganucleases (MN). Recently, the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) system associated to the Cas9 endonuclease (CRISPR/Cas9) superseded its predecessors. Specifically, CRISPR being a RNA-guided endonuclease (RGEN) system, it guaranteed an unprecedented ease of design and seamless synthesis8, and contributed to the recent advent of the CRISPR/ Cas9 for genome editing.
We have successfully generated numerous CRISPR edited mouse lines9-10 and currently develop new strategies to improve CRISPR efficiency and delivery to remain at the forefront of genome editing.
We offer microinjection and electroporation of CRISPR components and subsequent identification of edited animals.
8) Delerue F. & Ittner LM. (2015). Genome Editing in Mice Using CRISPR/Cas9: Achievements and Prospects. Cloning and Transgenesis 4:135. doi:10.4172/2168-9849.1000135.
9) Pleines I… Delerue F., Ittner L.M., Bryce N.S., Holliday M., Lucas C.A., Hardeman E.C., Ouwehand W.H., Gunning P.W., Turro E., Tijssen M.R., Kile B.T. (2017). Mutations in Tropomyosin 4 underlie a novel form of human macrothrombocytopenia. Journal of Clinical Investigations Mar 1;127(3):814-829. doi: 10.1172/JCI86154.
10) Tan D.C.S., Yao S., Ittner A., Bertz J., Ke Y.D., Ittner L.M., Delerue F. (2018). Generation of a New Tau Knockout (tauΔex1) Line Using CRISPR/Cas9 Genome Editing in Mice. Journal of Alzheimer’s Disease. 62(2):571-578. doi: 10.3233/JAD-171058.
GEM offers additional services to improve animal welfare, as recommended by the Australian code of practice for the care and use of animals for scientific purposes. These include:
- Rederivation of compromised mouse lines,
- Cryopreservation of sperm or oocytes for archiving of unused strains,
- In vitro fertilisation (IVF) for the reviving of cryopreserved lines,
- Aggregation chimeras services for developmental studies11.
We are also experienced with the importation of transgenic animals and can assist with the Australian Quarantine and Inspection Services (AQIS) regulations.
11) Chandrakanthan V… Delerue F., Ittner L.M., Mobbs R., Walkley C.R., Purton L.E., Ward R.L., Wong J.W., Hesson L.B., Walsh W., Pimanda J.E. (2016). PDGF-AB and 5-Azacytidine induce conversion of somatic cells into tissue-regenerative multipotent stem cells. Proceedings of the National Academy of Sciences of the United States of America.Apr 19;113(16):E2306-15. doi: 10.1073/pnas.1518244113.