Animal models
What is an animal model?
Animal models are species that are studied in order to understand particular biological mechanisms, so that the model organism helps to understand processes that occur in other organisms: the animal model can for allow to study the evolution of diseases that occur both in a certain animal species, and in humans.
The animal model at the center of Avantea's research is the pig, a species which, due to its physiological characteristics, is the closest to humans after primates.
Why are animal models fundamental in biomedical research?
Animal models can offer an approximation of a human disease and might help analyze the onset of diseases through the discovery of diagnostic markers, and allow for the implementation of preventive strategies or the testing of novel therapies. The use of the pig becomes necessary when human diseases are failing to reproduce in rodents or when size matters like in the case of neurodegenerative diseases, organ xenotranplantation or production of biomolecules in therapeutic quantities.
How is an animal model generated?
The use of the pig as animal model in the biomedical field has been consolidating in recent years thanks to the development of somatic cell nuclear transfer (cloning) and genome editing technologies (Zn Fingers, TALENS and CRISPR/Cas9). The procedure involves the required genome editing (deletion, insertion, point mutation, etc.) and selection of the desired mutated cell clone from primary fibroblasts. These cells are then used for somatic cell nuclear transfer to generate cloned embryos, which are implanted to surrogate recipients to carry the pregnancy to term, and resulting in the birth of an animal carrying such mutation.
Avantea contribution to research in the field
Avantea participates in important research projects at the national and European level, collaborating with authoritative scientific institutions and universities, in the field of xenotransplantation and in particular regarding the use of swine as an animal model, both in the biomedical and biotechnological sectors.
Avantea has participated to several EU funded RTD projects:
Avantea has also participated in SuperPig a project financed by the Lombardy region in Italy.
Avantea is also a founder of Xenothera.
Animal models produced by Avantea
With funds for research and new genome modification technologies, Avantea has been able to obtain different lines of pigs for biomedical purposes (for example, xenotransplantation of modified organs, tissues and cells, production of bioprosthetic valves) and to study some rare diseases human (ALS, Leigh syndrome, Retinitis pigmentosa, Timothy syndrome).
Avantea can provide lines of genetically modified cloned pigs within collaborative research programs or on specific contract according to the needs of each customer. The following lines are available.
Line | Genetic background | Mutation /disease (KO knock out, KI knock In) | Field of use | References |
|---|---|---|---|---|
V2G | Pig | Safe harbor /GFP | Transpalantation, tracking studies, overexpression of transgenes | Brunetti et. al,2008; EP2921048 A1 |
Xenome | Yucatan minipig cross bred | GGTA1-KO CD55/EPCR/TM- KI | Xenotransplantation | Perota et al 2012 |
Translink | Pig | GGTA1/CMAH/B4GalNT2-KO | Xenotransplantation, | Conchon et al 2013 |
Translink | Cattle | GGTA1/CMAH-KO | Xenotransplantation, | Perota et al 2019, |
ALS | Yucatan mini-pig | SOD G93A, Amiotrophic lateral sclerosis | Disease model | Chieppa et al 2014 |
TDP43 | Yucatan mini-pig | A382T, Amiotrophic lateral sclerosis | Disease model | Unpublished |
Surf1 | Pig | Surf1-KO, Leigh Syndrome | Disease model | Quadalti et al 2017 |
ABCA4 | Pig | ABCA4-KO, Stargardt disease | Disease model | Trapani et al 2018 |
CACNA1C | Pig | G406R, Timothy Syndrome | Disease model | Unpublished |
Animal cloning
Somatic cloning technique, better known as somatic cell nuclear transfer, is the procedure by which the nucleus of a cell (obtained from a skin biopsy of the animal to be cloned) is transferred into an oocyte deprived of its nucleus. In this way we obtain an embryo that, transplanted into the uterus of a recipient female, will develop into an animal genetically identical to the donor cell's skin. The cloning allows to produce genetic copies of animals of particular interest.
In addition, cloning may be associated with genetic engineering where the cells used for cloning have been genetically modified. In this case the cloned animal will bring the same genetic modification, and will then be a transgenic animal. This procedure is currently the most widely used to generate large animal models for biomedical research.
After the birth of the first cloned mammal from a somatic cell, Dolly the sheep in 1996, Avantea developed the cloning technique by adapting it to the biological characteristics of the various animal species, generating some of the "first clone" in cattle, horses and swine.
Galileo, first clone in the world of an adult bull
In 1999 at the Laboratory of Reproductive Technology the world's first clone of an adult bull was born: Galileo, a genetic copy of the famous American bull Zoldo. Galileo is not only the first cloned bull but it is also the first clone obtained using lymphocytes, white blood cells, collected from Zoldo. This technique was tested to demonstrate the ability to clone animals also through a simple blood sample.
Prometea, first horse clone in the world
In 2003 Avantea obtained the world record of the first cloned horse, the filly Prometea. This achievement was reported in the scientific paper published in Nature that makes it famous to the scientific community. Prometea is not only the first cloned horse but it also has a second characteristic that makes it unique: it was born from the same horse from which the cells used in nuclear transfer were derived
First cloned pigs
In 2005, Avantea obtained the first cloned pigs in Italy. Since then, the research activity is focusing on the pig cloning mainly used in biomedical research
References
Brunetti, D., Perota, A., Lagutina, I., Colleoni, S., Duchi, R., Calabrese, F., Seveso, M., Cozzi, E., Lazzari, G., Lucchini, F., et al. (2008). Transgene expression of green fluorescent protein and germ line transmission in cloned pigs derived from in vitro transfected adult fibroblasts. Cloning and stem cells 10, 409-419.
Chieppa, M.N., Perota, A., Corona, C., Grindatto, A., Lagutina, I., Vallino Costassa, E., Lazzari, G., Colleoni, S., Duchi, R., Lucchini, F., et al. (2014). Modeling Amyotrophic Lateral Sclerosis in hSOD1 Transgenic Swine. Neuro-degenerative diseases 13, 246-254.
Conchon, S., A., P., Concordet, J.P., Judor, J.P., Lagutina, I., Duchi, R., Lazzari, G., Brouard, S., Cozzi, E., Soulillou, J.P., et al. (2013). Generation of CMAH-/- piglets on GAL-/- genetic background. Xenotransplantation 20, 370-371.
Crociara, P., Chieppa, M.N., Vallino Costassa, E., Berrone, E., Gallo, M., Lo Faro, M., Pintore, M.D., Iulini, B., D'Angelo, A., Perona, G., et al. (2019). Motor neuron degeneration, severe myopathy and TDP-43 increase in a transgenic pig model of SOD1-linked familiar ALS. Neurobiology of disease 124, 263-275.
Perota, A., Lagutina, I., Colleoni, S., Duchi, R., Lazzari, G., Cozzi, E., Lucchini, F., and C, G. (2012). Efficient expression of human endothelial protein c receptor and human thrombomodulin in transfected pig primary hCD55-Gal-/- fibroblasts using f2a expression vector. Reproduction Fertility and Development 24, 229-230.
Perota, A., Lagutina, I., Duchi, R., Zanfrini, E., Lazzari, G., Judor, J.P., Conchon, S., Bach, J.M., Bottio, T., Gerosa, G., et al. (2019). Generation of cattle knockout for galactose-alpha1,3-galactose and N-glycolylneuraminic acid antigens. Xenotransplantation, e12524.
Quadalti, C., Brunetti, D., Lagutina, I., Duchi, R., Perota, A., Lazzari, G., Cerutti, R., Di Meo, I., Johnson, M., Bottani, E., et al. (2018). SURF1 knockout cloned pigs: Early onset of a severe lethal phenotype. Biochim Biophys Acta 1864, 2131-2142.
Trapani, I., Perota, A., Tiberi, P., Colecchi, L., Lagutina, I., Duchi, R., Lazzari, G., Gesualdo, C., Rossi, S., Testa, F., et al. (2018). Genome Editing to Generate a Pig Model of Stargardt Disease Type 1. Molecula Therapy 26, 403-404.