Characterization studies of early embryonic development are limited, mainly due to the lack of samples and the obvious legal and ethical limitations. The genome editing technique CRISPR/Cas9 represents an important tool to study embryo development. This technique acts as directed scissors that modify specific DNA sequences or genes. The CRISPR/Cas9 technique has potential in the treatment of single-gene mutation diseases, because it can be used to eliminate or repair mutated genes in embryos, and thus prevent the birth of children with genetic diseases. Its application is also useful to study the role of genes in embryonic development, as in the project proposed. However, there are still technical limitations for these applications. On the one hand, it is necessary to modify all embryo’s cells and avoid what is called embryonic mosaicism – the mosaic embryos are those that have cells with a correct number of chromosomes and others chromosomally altered-. Also, there is a risk of altering other genes apart from the gene of interest (what is called off-target mutations), which could lead to significant side effects.

The research group of Dra. Anna Veiga, group leader of the Regenerative Medicine Program of IDIBELL and Pluripotent Stem Cell Therapy of P-CMR[C], director of R&D in Biology of the Reproductive Medicine Service of Dexeus Mujer, is starting a project called “Genomic edition through CRISPR/Cas9 in human embryos for the study of early embryonic development. EMBRYOCRISPR“, in which, through genome editing by CRISPR/Cas9, several genes that are relevant for embryonic development will be studied. The project consists in the development of genetic edition by CRISPR/Cas9 in human embryos to modify some of these genes and evaluate the development of edited embryos in the early stages.

Human embryos from the In Vitro Fertilization Program (IVF) of Dexeus Mujer’s Health Service will be used in this project.  Those embryos are from IVF cycles carried out in this center, that have been voluntarily and altruistically donated for research by their progenitors.

Another novelty of this project is the technique used for embryo developmental assessment (morphokinetic evaluation, time lapse) which allows continuous and real-time observation of their development.

Cellular and molecular biologists from IDIBELL , who will perform genome editing, and molecular and immunocytochemical analyzes of the edited embryos will collaborate with clinical embryologists with extensive experience in embryonic culture and preimplantation genetic screening techniques of Dexeus Mujer, who will assess the efficiency and safety of genome editing in human embryos, by the analysis of it developmental capacity and characteristics.