Site-specific integration of transgene for the generation of genetically modified bovine embryos

• Grant number: 12/50726-5
• Support Opportunities: Regular Research Grants
• Start date: June 01, 2013
• End date: May 31, 2015
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Agreement: CNPq - First Projects Program
• Principal Investigator: Marcella Pecora Milazzotto
• Grantee: Marcella Pecora Milazzotto
• Host Institution: Centro de Ciências Naturais e Humanas (CCNH). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil

Abstract

The injection of exogenous DNA into the pronucleus of a zygote has been the most commonly used strategy in the last 30 years for the generation of genetically modified animals. Although its efficiency, there is still several technical limitations, in particular for farm animals, as the difficulty in visualizing the pronucleus, the incapability in controlling the integration site, the integrity of the DNA molecule and the quantity of copies inserted. The insertion of exogenous DNA randomly into the host genome can interrupt the function of endogenous genes or even promote silencing of the inserted gene. In this regard, studies are now turned to the development of strategies to promote the site-specific insertion of exogenous DNA. Several strategies have been developed for this purpose, mainly for mice, as the use of integrases and recombinases that mediate the insertion of the transgene at specific sites in the genome. Although widely used, these enzymes act on the basis of specific DNA sequences however these sites are often lacking in organisms of interest for the pharmaceutical industry and agriculture. Thus, this project aims to generate a strain of bovine fibroblasts with the stable introduction of a vector with multiple sites of recombination / integration. This strain can be subsequently used for the generation of an animal which presents these sites enabling the generation of genetically modified animals in a more efficient and site-directed manner. (AU)