embryonic development

A new technique developed at the Institut de Bioenginyeria de Catalunya (IBEC) has succeeded in assessing the health of mouse oocytes and embryos in a non-invasive way, according to a study published in PNAS. The method generates 3D images to visualise the metabolism of oocytes and embryos obtained by in vitro fertilisation and makes it possible to select those that are most likely to implant and develop, say the authors.

A multidisciplinary team of researchers has succeeded in developing different types of organoids from cells obtained from amniotic fluid. According to the authors, this breakthrough could help to better understand the later stages of development during pregnancy and to advance research into congenital anomalies. The study is published in the journal Nature Medicine.

A team of Chinese researchers report today in the journal Nature Communications the successful cloning of a rhesus monkey, with a healthy placenta, which survived for more than two years. According to the authors, this could improve the efficiency of the monkey cloning process, which so far is very low. Previously, different teams have cloned more mammalian species, including 'Dolly the sheep' and another species of macaque (Macaca fascicularis).

A Chinese research team has reported the birth of a crab-eating macaque that is a chimera: an animal generated from the mixing of embryonic cells from two different individuals; in this case, from the same species, according to the journal Cell. Until now, this type of chimera had only been developed with rodents. This is the first time it has been achieved in non-human primates.

Scientists have successfully developed pig embryos whose kidneys contain 50-60% human cells. Gestation was terminated at 25-28 days, and the organ structure was normal. According to the press release accompanying the article, "this is the first time that a solid humanised organ has been grown inside another species, although previous studies have used similar methods to generate human tissues". The results are published in the journal Cell Stem Cell. 

Berna Sozen's lab at Yale University has announced a new milestone in the competition to create synthetic embryos: their human pluripotent stem cells self-organise into structures that mimic embryonic development on days 9-14 after fertilisation and include extra-embryonic tissues. Their achievement is published in Nature at the same time as another similar study, that of Magdalena Zernicka-Goetz, who a fortnight ago previewed her stem cell-derived human embryo model to The Guardian, sparking a controversy with Jacob Hanna, author of a preprint showing that she had achieved true synthetic embryos. 

The Guardian newspaper reported on Wednesday that Magdalena Zernicka-Goetz's team had announced the generation of synthetic human embryos from stem cells at the annual meeting of the International Society for Stem Cell Research in Boston. The author later denied on Twitter that they were synthetic human embryos and spoke only of models, warning that it was pending publication in a scientific journal. The day after the publication in The Guardian, and as reported in El País, Jacob Hanna and his team published a preprint - a publication that has not been peer-reviewed - in bioRxiv on models of human embryos generated from stem cells without genetic editing. A few hours later, Zernicka-Goetz's team posted their preprint on bioRxiv.

The latest episode of competition between research groups working on the same topic, a very common situation in science, should not distract us from the actual achievement: synthetic human embryos, in the laboratory, made from stem cells, up to a post-implantation stage. Now, we must decide what status or condition we will grant to these synthetic embryos. Once again, science is leaping forward and testing the limits of the laws, posing new ethical challenges for us to solve. 

A scientific team has generated synthetic human embryos using stem cells, reports the British newspaper The Guardian. The authors, who announced the breakthrough at the annual meeting of the International Society for Stem Cell Research in Boston (USA), say the model embryos, similar to those found in the early stages of human development, could be crucial for research into genetic disorders and the causes of miscarriages, according to the newspaper. However, the work also raises ethical and legal issues.

Chinese researchers have succeeded in developing macaque embryo-like structures from embryonic stem cells. They have also managed to implant them in the uterus of female macaque monkeys and develop a hormonal response similar to that of a gestation, although they have only survived for about a week. According to the authors, whose research is published in Cell Stem Cell, these models could be used to improve our understanding of embryonic development and to investigate the causes of some early miscarriages.