Hermann Bujard, a molecular biologist who was behind the Tet-Off system worked for many years at the ZMBH in Heidelberg. He sadly passed away on the 31st of July at the age of 86. I thought I would post a message to the ISTT Blog, reflecting how important some of his ideas and technical achievements have been for the development of transgenic technologies.
The integration of single copy transgenes in a safe harbor permissive for gene expression will be satisfied by targeting transgenes to the mouse ROSA26 locus and the rat ROSA26 locus with Cas9 technology. Single copy transgene integration is essential to facilitate the analysis of endonuclease activity on transgenes. Conventional methods to produce transgenic mice and rats by pronuclear microinjection of linear DNA fragments in zygotes results in the multicopy transgene integrations in random sites (Brinster et al., 1985, Srivastava, 2014). Because resulting integration sites are randomly distributed over the genome no two founder animals identical integrated transgene alleles. Single copy transgene integration in a specific genomic target, ROSA26, will provide for facile, rapid analysis Cas9 chromosome break and repair events at defined sgRNA targets.
The International Society for Transgenic Technologies (ISTT, Inc.) is delighted to announce that the 13th ISTT Prize will be awarded to Dr. Alexandra Joyner for her pioneering work on homologous recombination in embryonic stem cells. The ISTT Prize is awarded to investigators who have made outstanding contributions to the field of transgenic technologies. The selection of Dr. Joyner as the 13th ISTT Prize winner was made by the ISTT Prize Committee, composed of previous ISTT prize awardees, the ISTT President, (Wojtek Auerbach), the ISTT Vice-president, (Benoit Kanzler), and the CEO of genOway (Alexandre Fraichard) . GenOway generously sponsors this prestigious award.
NABR has filed an official complaint with the U.S. Department of Transportation (DOT) regarding the refusal of major airlines to carry animals for the purpose of research. Opponents to animal research have now activated their grassroots networks and are flooding the docket with individual comments.The ISTT has written a letter of support to show the DOT how critical this issue is to the future of biomedical research.
The ISTT is a scientific society whose members are generating and/or studying genetically modified animals and often engaged in assisted reproductive technologies. Although the use of animals is currently unavoidable we recognize that work is being done to develop alternative non-animal models in keeping with the 3Rs principle of replacement. Our membership is aware of our responsibility towards the animals we use for our work including the expectation that animal use will be reduced and the lifetime experience of experimental animals refined in accordance with the 3Rs principles of humane experimental technique.
The new and accelerating technical development of the CRISPR/Cas9 system opens up for the possibility of targeted genetic modifications in germline competent human embryos. This is an avenue, which until very recently has been regarded as absolutely off limits. To cross the border between genetic modifications of somatic cells and germline cells was simply not conceivable, at least in most Western countries. Indeed, the border has not yet been crossed, but we are getting closer.