Establishment of novel Expanded Potential Stem Cells (EPSCs) from bovine pre-implantation embryos: in vitro and in vivo studies.

• Applicant: Dr. Monika Nowak-Imialek
• Subject Area: Animal Breeding, Animal Nutrition, Animal Husbandry ; Veterinary Medical Science
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 465494419

In many species including humans, rats, mice and monkeys embryonic stem cells (ESCs) can be derived from the inner cell mass of pre-implantation embryos, so-called blastocysts. These cell lines can self-renew and grow in vitro for indefinite time. However, despite many efforts, bona fide pluripotent stem cell lines could not yet be derived from cattle. While some progress has been made, reported bovine ESC lines do not meet the stringent criteria for pluripotency, i.e. the capacity to form germ line chimeras. Recently, embryonic stem cell lines were derived from porcine embryos using novel, so-called “expanded culture conditions”. These cells, named Expanded Potential Stem Cells (EPSCs), possess the special characteristics of being able to differentiate not only into different cell types of the body but also into extraembryonic tissue. The aim of the proposed research is to establish bovine Expanded Potential Stem Cells (bEPSCs) from in vitro produced embryos. These cells should remain undifferentiated indefinitely under appropriate in vitro culture conditions and at the same time possess the ability to differentiate into any cell type of the body in vitro and in vivo, including their contribution to the germ line and eventually the production of functional gametes. In the proposed studies, we plan to use a novel Expanded Potential Stem Cell Medium (EPSCM) to establish bovine embryonic stem cell lines. Embryonic stem cells will be isolated from 8-to-16-cell-stage embryos and from blastocysts (Objective 1) and characterized by morphology, in vitro growth, karyotype stability, pluripotency gene expression, accessibility for genetic manipulation and differentiation potential in vitro (Objective 2). We anticipate that by using EPSC culture conditions we will be able to establish bovine Expanded Potential Stem Cell (bEPSC) lines. These stem cells would be similar to pre-implantation blastomers, with the ability to generate germline chimeras after re-introduction into bovine pre-implantation embryos (Objective 3). The proposed work will provide unique bovine stem cell lines with expanded potential that can be great candidates to introduce multiple genetic modifications and enable the generation of transgenic animal models. These cell lines with expanded potential to differentiate into all embryonic and extraembryonic cell types could be of great interest for reproductive biotechnology as well as for innovative in vitro breeding methods.

• DFG Programme: Research Grants
• International Connection: Poland
• Cooperation Partner: Professorin Dr. Izabela Woclawek-Potocka