Scientists trying to find out ‘black box’ of human development

TOKYO (NUT DESK)  Scientists have generated early-stage human embryo models that could help shed light on the “black box” of initial human development stages and improve research on pregnancy loss and birth defects. Two separate teams found different ways to produce versions of a blastocyst — the pre-embryonic mass of cells at the stage of development around five days after a sperm fertilises an egg — potentially opening the door for a huge expansion of research.

The scientists make clear that the models differ from human blastocysts and are not capable of developing into embryos. But their work comes as new ethical guidelines on such research are being drafted and could spark fresh debate. The teams, whose research was published Wednesday in the journal Nature, believe the models dubbed “blastoids” will aid research on everything from miscarriages to the effects of toxins and drugs on early-stage embryos. “We´re very excited,” said Jun Wu of the University of Texas Southwestern Medical Centre, who led one of the teams. “Studying human development is really difficult, especially at this stage of development, it´s essentially a black box,” he told a press briefing ahead of the research´s publication. At the moment, research on the earliest days of embryonic development relies on donated blastocysts from IVF treatment. But supply is limited, subject to restrictions, and available only to certain research facilities. So being able to generate unlimited models could be a game changer, said Jose Polo, a professor at Australia´s Monash University, who led the second research team. “This capacity to work at scale, we think, will revolutionise our understanding of early stages of human development,” he told reporters. Generating models of blastocysts has so far only been done in animals, with researchers in 2018 successfully generating them in mice using stem cells. The two teams approached the development of a human model in slightly different ways.