Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Final Activity Report Summary - CLONET (Training Network on Novel Animal Models for Medical Purposes)

Somatic cell nuclear transfer (SCNT, cloning) is one of the most promising techniques in biomedicine. However, it is strongly limited by inefficiency and imperfection of the genetic reprogramming of the somatic cell genome into a developing embryo nuclear material with a negative impact on the welfare of the resulting animals. The CLONET project was aimed to improve the efficiency and safety of the SCNT technology and to create a solid background for the generation of new model animals and cell lines by this technology for biomedical research. Using two model species, the mouse and the rat the project has created major progress in the generation of cloned cell lines, live mice and their progeny for a detailed pheno- and genotyping analyses, for analyses of the reprogramming process, mitochondria and gene expression in embryonic stem cell lines generated from SCNT-embryos.

Studies of early events of SCNT embryo development, when newly formed genetic information starts to be expressed showed altered epigenetic marks including non-reprogrammed genomic regions. The activation of the ribosomal RNA (rRNA) genes associated with the formation of functional ribosome-synthesising nucleoli has been one cell cycle delayed in mouse SCNT embryos which may be causally involved in the reduced viability of SCNT embryos. Validation of the mouse nuclear replacement technology resulted in large number of SCNT embryos, from which new embryonic stem (ES) cell lines have been established and analysed further. The main results include the birth of the 1st Hungarian cloned mouse. The cloned mice were bread to 2nd and 3rd generations, and using the infrastructure of the German Mouse Clinic, a comprehensive geno- and phenotypic analysis has been performed which represents an important corner stone in the validation of SCNT technology. Moreover, new methods towards generating more efficient gamete and embryo cryopreservation techniques have been developed and fully optimised on mouse, as a model organism. In rat SCNT we reasoned that the failures are likely due to the lack of maturation promoting factor (MPF) in rat oocytes. Therefore we modified the protocol and successfully improved the in vitro development of rat SCNT embryos, although we still could not succeed to deliver live cloned rats.

The new knowledge on the reprogramming of somatic cells exposed to the oocyte environment paves the way for production of pluripotent stem cells without requirement to create an embryo. Indeed, alternative genetic induction methods to reprogram somatic cells (iPS) have been tested as well, thus the results of this project will promote establishing Europe as a world leader in innovative cell-based therapies. Overall, the results are expected to have a positive long term impact on a spectrum of medical research landscapes in Europe by generating model systems for further research.

The above research and an extensive program of 15 scientific and 6 complementary trainings improved the scientific career possibilities for the recruited 14 young researchers (ESRs). Most of them obtained PhD degrees among them 3 via intersectorial collaborations. The published scientific papers and training experience have opened access to advantageous positions for the ESR's - 36% of them, all woman, completed a successful intersectorial career move into SMEs immediately after the CLONET period, contributing to the enrichment and development of the ERA and proving the success of the project towards opening new opportunities for women in scientific careers. Remarkably, 3 of them obtained MC European Reintegration Grants which is a testimony for the excellent portfolio they developed during the project. Exchange of knowledge and experiences between scientific organisations and industry via research and personnel in CLONET is expected to increase European competitiveness in the field of animal models and cell based therapies.

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