Spanish researchers filming embryos for the first time | The doctor’s daily life | Specialties

It is only a series of very short videos, but it is a world first. Nevertheless, Researchers from the Institute of Bioifenieu de Catalonia. For example, in Barcelona, have managed to film in real time, and from all angles, the establishment of human and murin embryos. Meanwhile, In color thanks to fluorescence. However, and captured by cameras capable of measuring the traction forces, these images provide information on the mechanical action exerted by blastocysts to integrate into the endometrium.

During the establishment. Therefore, the epiblast of the blastocyst is differentiated in order to produce embryonic fabric, and goes from a spherical shape to a structure with two axes of symmetry (dorso-ventral and anteroposterior). In addition, The trophectoderm penetrates the endometrium and gradually gives birth to the placenta. For example, During this process. Moreover, the secret embryo of metalloproteinas in order to degrade the spanish researchers filming embryos first extracellular matrix of the uterine endometrium and facilitate the grip. But this enzymatic action is not enough. If we knew that a mechanical force should be involved to “push” the embryo in the endometrium. the impossibility of directly observing an implantation made the understanding of the mechanisms in play difficult.

To manage to film an establishment, Barcelona researchers explain in their article published in Science Advance have combined several technologies. They have developed an ex vivo implantation platform compatible with fluorescence imaging technologies in real time. measurement microscopy of traction forces. There are significant differences between the implantation of a human embryo. which is fully climbed inside the uterine tissue and that of a mouse embryo, which remains on the surface of the uterine tissue. The authors found that the murine. human embryos generated forces during the implantation, according to a scheme specific to each species. They have also spanish researchers filming embryos first shown that embryos are mechanical. receptive and that an external stress can determine the orientation of the proximo-distal axis in mice and promote implantation in the human embryo.

Spanish researchers filming embryos first

IVF applications

When applying forces on the endometrium. the embryo of the mouse exerts travel in an anisotropic way, that is to say with two or three privileged directions. Conversely, the human embryo begins by exerting a single force, not very marked and localized, then evolves. Over time, it generates several traction or strength points, in several directions. Thus. mouse embryos are able to adapt more easily to the position and composition of the matrix in which they try to set up.

Researchers’ observations “Specify the hypothesis that the mechanical environment could guide the establishment of mammal embryos. »» The human uterus has spontaneous contractions with frequencies of 1 to 1.6 contraction/min, which vary through spanish researchers filming embryos first the phases of the menstrual cycle. Therefore. “Human embryos can be exposed to these uterine contractions and to the associated forces during the establishment, Recall the authors, who consider their results consistent with literature. “During an IVF. patients who will have a positive pregnancy test have had contraction frequencies similar to those of women in the luteal cycle (high, conducive to implantation) while those who had a negative pregnancy result had a frequency of uterine contraction reduced to the day of the transfer of embryothey continue. A reduced frequency (less than 2 contractions/min) on the day of the transfer of embryos has shown lower implantation. pregnancy rates because the risk of expulsion of the embryo of the uterus is greater ”. “This suggests that there can be an optimal frequency range favorable to the implementation of embryos”, they conclude.