March 2012

Jan Christian, Ph.D.
Professor of Neurobiology & Anatomy and Internal Medicine
University of Utah
Salt Lake City, Utah

I used the services of the OHSU Transgenic Core several times during 2009- 2011. Under the direction of Lev Fedorov, the core  successfully generated new embryonic stem cell lines carrying modified genes of interest for my lab. They also generated genetically modified mice by targeted injection of ES cells into mouse blastocysts. Lev also met with me and members of my lab on many occasions and helped us to troubleshoot problems that we had with stem cells and mice that were generated in another facility prior to 2009. In the past eight years, I have worked with three different transgenic facilities to generate targeted embryonic stem cells and genetically modified mice. The current team of the OHSU Transgenic Core has offered the highest level of technical expertise and service.

February 2012

Peter G. Gillespie, Ph.D.
Professor of Otolaryngology
Oregon Hearing Research Center & Vollum Institute
Oregon Health & Science University
Portland, Oregon 

The OHSU Transgenic Core performed embryo cryopreservation of several lines, as well as reconstitution of mouse line from cryopreserved embryos during 2010-2012. The service quality was excellent.

February 2012

Michael Forte, Ph.D.
Senior Scientist and Professor
Vollum Institute
Oregon Health and Science University
Portland, Oregon

From 2009-2012, I have had the OHSU Transgenic Core help us with two projects. First, they assisted us in the creation transgenic lines in which an endogenous gene was replaced by a gene containing loxP sites to allow conditional elimination. We have just started to cross these mice to Cre containing line. Recently, we have shown that the gene is effectively eliminated, and protein absent, in the livers of albumin-Cre mice. Second, the Transgenic Mouse Core has helped us use ES cells containing a specific gene-trap line to generate mice in which the expression of this gene is effectively eliminated. Ultimately, both sets of mice will be shared with an Italian group and the loxp mice, with a group in Canada. The OHSU Transgenic Mouse Core has always provided outstanding and provided timely service.

December 2011

Marcus Grompe, M.D.
Professor at Oregon Health & Science University
Director at Papé Family Pediatric Research Institute
Director of the Oregon Stem Cell Center at OHSU
Portland, Oregon

The OHSU transgenic core has provided a variety of important services for my lab, including very recently:  Strain re-derivation by embryo transfer; Creation of BAC transgenic mice. The transgenic project was a very difficult one and the core performed expertly. We wished to introduce a BAC transgene on the background of a mouse that already had 4 mutations. An additional challenge was that embryos are lethal and to survive mothers must be kept under special diet. Standard transgenic technology would have been to first generate the BAC transgenics and then introduce the transgene onto the quadruple mutant background by backcrossing. Due to the large number of mutations this would have taken at least 18 months. Fortunately, through the skill of Dr. Fedorov, the transgene was microinjected into quadruple mutant embryos. Two founder lines were generated and have been bred successfully. Thus, we were able to generate the desired strain of mice in a single step, saving us 18 months! Importantly, this new strain of transgenic mice is now subject of a patent application and represents valuable intellectual property for OHSU... We have several ESC knockout projects that we plan to conduct in 2012.

December 2011

Ronen Schweitzer, Ph.D.
Associate Professor
Shriners Hospital - Research
Department of Cell and Developmental Biology
Oregon Health & Science University
Portland, Oregon

Our lab uses mice very extensively. This year we have so far generated four transgenic mice using the transgenic core at OHSU, and since we were very happy with the results we have already initiated two additional transgenic projects. Production of mice is both an expensive and lengthy process. Efficient and timely production is thus crucial for our research and for our competitiveness in publications and grant applications. Working with the transgenic core at OHSU gives us a few significant advantages in that respect. Most significantly, the flexibility of an in house service and the ability to receive the mice without quarantine reduces the effective time for the project by close to 6 months. That was critical for the enhancer bashing project that we performed earlier this year with the core's help, and would be difficult to justify with the extra time it would take in an external facility.

December 2011

Anthony Paul Barnes, Ph.D.
Papé Family Pediatric Research Institute
Oregon Health & Science University
Portland, Oregon

My recent experience as a transgenic core user was very good. I found Dr. Fedorov to be very available and willing to discuss the details of my project. For example, we had chosen a targeted embryonic stemcell line that did not require a feeder cell layer. Lev spent time to explain the pros and cons of such cells, and what we might expect in terms of success rates. He was able to successfully generate multiple chimera founders. I believe that our ability to generate our line was due in part to the care with which Lev approaches his science. He was very helpful with assisting us in identifying the appropriate media and conditions required for these cells. My laboratory along with a collaborator on campus has also begun planning a transgenic reporter line that would require a pro-nuclear injection approach. In this case, Lev has met with us to ensure the correct purification of our vector for the best chance of genomic insertion and activity. We have also utilized the core facility for cryo-presevation of multiple mouse lines. This provided a cost-effective way to maintain our experimental flexibility should we need these lines for future analysis in the context of other mouse lines we have you to employ.

December 2011

Kari J Buck, Ph.D.
Professor
Veterans Affairs Medical Center
Behavioral Neuroscience at Oregon Health & Science University
Portland, Oregon

My lab is regular customer of OHSU Transgenic Core. Transgenic Core generated Mpdz Bacterial artificial chromosome transgenic mice for our laboratory in past.  Recently several our congenic mouse strains were cryopreserved via embryo cryopreservation .  Very good quality service.    

November 2011

Malcolm J. Low, M.D., Ph.D.
Professor of Molecular & Integrative Physiology and Internal Medicine
University of Michigan
Medical School

During 2008-2010 my lab used the services of the OHSU Transgenic Facility on several occasions. In each case we received very qualified and timely results at competitive prices. The Core generated aggregation chimeric embryos from two independent strains of transgenic mice and we were able to detect a wide range of neuronal chimerism based on expression of the two reporter genes in distinct cells in mouse embryonic brain and pituitary gland.  In addition, Dr. Fedorov developed new C57BL/6 embryonic stem cell lines from genetically modified mice for my project and that of another professor at OHSU. The stem cells generated for my lab inherited a histochemically detectable reporter gene (green fluorescent protein) exclusively expressed in certain population of neurons in mouse brain together with a homozygous null mutation for the endogenous gene. These results are not yet published as we continue our collaboration to use the new ES cells for the development of aggregation chimeras in combination with another targeted transgenic model.  Finally, the core cryopreserved embryos for us from a mutant mouse line that we were no longer actively using and tested an aliquot of the  frozen embryos for viability by retrieving live mice following embryo transfer into psuedopregnant recipients.

September 2011

Soren Impey, Ph.D.
Assistant Professor
Oregon Stem Cell Center at Oregon Health & Science University
Portland, Oregon

The OHSU Transgenic Core performed injection of ES cells into blastocyst and assistance with embryo dissection. The transgenic core provided excellent advice on planning and execution of experiments. The core also helped provide assistance in training for work with early embryos. The transgenic core is extremely important to our research program on stem cell self-renewal and pluritipotency.