embryonic development

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.

Researchers in the United States have tested a new technique to select sperm and thereby increase the chances that the embryo will be of either sex. The proven efficacy is around 80 %. Although some countries such as the United States allow this type of procedure, in Spain it is prohibited except in cases of prevention of diseases linked to sex chromosomes. The authors of the article state that sperm selection is more ethically acceptable than embryo selection. The results are published in the journal PLOS ONE.

Research published in Nature shows the creation of synthetic mouse embryos derived from stem cells. The embryo model copies the stages of natural rodent embryo development that take place up to day 8.5 after fertilisation and includes regions of the brain, a neural tube and a structure similar to a beating heart.