Navigation Links
Scientists revolutionize the creation of genetically altered mice to model human disease

CAMBRIDGE, Mass. (May 2, 2013) Whitehead Institute Founding Member Rudolf Jaenisch, who helped transform the study of genetics by creating the first transgenic mouse in 1974, is again revolutionizing how genetically altered animal models are created and perhaps even redefining what species may serve as models.

"This new method is a game changer," says Jaenisch, who is also a professor of biology at MIT. "We can now make a mouse with five mutations in just three to four weeks, whereas the conventional way would take three to four years. And it's rather straightforward, probably even easier than the conventional way."

Scientists create models in mice by altering specific genes that have been associated with a given disease. The models allow for the study of the development and course of the disease and the effects of various interventions, including genetic and chemical. For the past 20 years, the creation of such models has remained relatively unchanged: scientists insert a piece of DNA into a mouse embryonic stem (ES) cell, inject the modified cell into a very early-stage embryo, called a blastocyst, then implant this developing ball of cells into a foster female mouse. The whole process can take years and tens of thousands of dollars to establish a mouse strain with, for example, a single copy of a gene "knocked out". Such knockouts can only be created in very few species, including mice and rats, whose ES cells can be grown and modified reliably.

The new approach used by scientists in Jaenisch's lab bypasses ES cells to quickly and efficiently produce mice with mutations in both copies of multiple genes. In next week's issue of the journal Cell, Haoyi Wang, Hui Yang, and Chikdu Shivalila describe their technique, which is based on a system that certain bacteria use to fend off viral attacks.

This is the first time that the system, known as CRISPR (for "clustered regularly interspaced short palindromic repeat")/Cas (for "CRISPR-associated"), has been used to alter multiple genes in a single multicellular organism. Shivalila says the process is so accessible that he expects other labs to adopt it quickly.

"For any institution or university with a core facility, we think this will be the way they will start making mice carrying specific mutations because it's a lot faster and so efficient," says Shivalila, one of Jaenisch's graduate students. "We were surprised that we could get two genes 'knocked out' at four loci very, very efficiently, about 80% efficiency. If we used TALENs, a more recent and complicated development in genetic engineering, we got 30% efficiency for just one gene."

Because the CRISPR/Cas technique can generate mutant mice even without using ES cells, a limitation of the conventional method for making models, genetic research may no longer be confined to a limited list of model organismsthose for which ES cells exist.

"This breaks down the definition of model organism," says Wang, a postdoctoral researcher in Jaenisch's lab. "So now, even with limited resources, any animal with established embryo manipulation procedures could be the subject of genome engineering. With many of the animals' genomes that have been sequenced, we could use this technology to establish efficient genetic manipulations in more species, to study the unique biology of each, and to learn more about evolution."

Thus, Wang, Yang, and Shivalila have used CRISPR/Cas to create mouse models only, but the team is excited broaden its application to other animals.

"We also need to see if the CRISPR/Cas system has any unexpected, undesired off-target effects, changes to the genome that we don't want," says Yang, a postdoctoral researcher in the Jaenisch lab. "So we need study this further to establish the fidelity of the system. But I think this will be the way to go."


Contact: Nicole Rura
Whitehead Institute for Biomedical Research

Related medicine news :

1. Scientists Pinpoint Most Major Genes Behind Deadly Blood Cancer
2. Temple scientists weaken HIV infection in immune cells using synthetic agents
3. HIV Cure Looks Promising, Danish Scientists Contend
4. Guelph scientists develop first vaccine to help control autism symptoms
5. Scientists Spot Cancer Metabolism Changes
6. Work By Female Scientists Gets Judged More Harshly: Study
7. Scientists May Have Spotted Brains Numbers Center
8. Scientists scan the human heart to create digital anatomical library
9. Scientists Create Breast Cancer Survival Predictor
10. Molecule treats leukemia by preventing cancer cell repair, Jackson Laboratory scientists report
11. Scientists map elusive 3-D structure of telomerase enzyme, key actor in cancer, aging
Post Your Comments:
(Date:11/26/2015)... Viejo, CA (PRWEB) , ... November 26, 2015 ... ... users a new set of retro-fused, self-animating trailer titles with ProTrailer: Vintage. This ... style options. These classically-influenced trailer titles work with any font, giving users limitless ...
(Date:11/25/2015)... IN (PRWEB) , ... November 25, 2015 , ... ... water accessible for all, Water For Empowerment ™ attracts volunteers together who ... clean water by empowering women as key stakeholders in the process. The non-profit ...
(Date:11/25/2015)... ... November 25, 2015 , ... TyloHelo Inc , North ... , Sauna accessories help improve the bather experience in the sauna, and the ... for the purist looking for simplicity in design to accessories that encourage a ...
(Date:11/25/2015)... Friendswood, TX (PRWEB) , ... November 25, 2015 , ... ... through the companies’ “ Two Organizations, One Beat ” campaign. The partnership between the ... its services to aid in MAP International’s cause. , MAP International was founded in ...
(Date:11/25/2015)... ... November 25, 2015 , ... On November 25, 2015, officials of Narconon ... announced the release of a new cutting edge recovery program that has been 50 ... with drug- and alcohol-addicted individuals with the purpose to free addicts from the symptoms ...
Breaking Medicine News(10 mins):
(Date:11/25/2015)... , Nov. 25, 2015  Linden Care, LLC, a ... treatment outcomes for patients suffering from chronic pain, said ... a Temporary Restraining Order (TRO) enjoining Express Scripts from ... companies. --> --> ... of its legal options. --> ...
(Date:11/25/2015)... AVIV, Israel , November 25, 2015 ... (NASDAQ: KTOV ) (TASE: KTOV), a biopharmaceutical company ... simultaneous treatment of various clinical conditions, today announced the ... 3,158,900 American Depository Shares ( ADSs ), each representing ... purchase up to 3,158,900 ADSs. The ADSs and warrants ...
(Date:11/25/2015)... , Nov. 25, 2015 Endo International plc (NASDAQ: ... De Silva , President and CEO, will discuss corporate updates ... in New York on Wednesday, December ... . Click on Investor Relations, and then the link to ... the presentation,s start time to visit the site and download ...
Breaking Medicine Technology: