Human embryos created in the laboratory without sperm or eggs
Scientists have developed structures similar to the human embryo without sperm or eggs, a new hope for research into miscarriages and birth defects that nevertheless raises ethical questions.
A group of researchers published their research in the scientific journal Nature on Wednesday, describing how they managed to create a similar embryo from human embryonic stem cells.
Scientists have hailed the work as an "impressive" breakthrough that could unlock the secrets of the first days of pregnancy,
when failures are most common.
These findings continue to fuel the debate on clearer ethical rules on laboratory development of human embryonic models.
The group of researchers, led by Palestinian Jacob Hanna of the Weizmann Institute of Science in Israel, produced 14-day-old human embryos, the legal limit for such research in many countries, until organs like the brain begin to develop.
The researchers said their work differed from previous ones on the subject, because they use chemically modified cells rather than genetically, and because their models, with yolk vesicle and amniotic cavity, are more like human embryos.
These similarities may make these models more effective for research on miscarriage, genital malformatics and infertility, said James Briscoe of the Francis Crick Institute in London.
The structure created "seems to produce all the different types of cells that form tissues at this early stage of development," he said.
This study "is a step towards understanding a period of human development that leads to the failure of many pregnancies, and which has always been very difficult to study until now."
The researchers behind the study and other scientists insisted that the structures created should not be considered human embryos.
They "strongly resemble, but are not identical" to human embryos, the study said.
This and other recent work shows that "models of human embryos are becoming more sophisticated and closer to what can happen during normal development," said Darius Widera, a cell biology expert at the University of Reading.
The text stresses "that a robust regulatory framework is more necessary than ever", he insisted.
A group of researchers published their research in the scientific journal Nature on Wednesday, describing how they managed to create a similar embryo from human embryonic stem cells.
Scientists have hailed the work as an "impressive" breakthrough that could unlock the secrets of the first days of pregnancy,
when failures are most common.
These findings continue to fuel the debate on clearer ethical rules on laboratory development of human embryonic models.
The group of researchers, led by Palestinian Jacob Hanna of the Weizmann Institute of Science in Israel, produced 14-day-old human embryos, the legal limit for such research in many countries, until organs like the brain begin to develop.
The researchers said their work differed from previous ones on the subject, because they use chemically modified cells rather than genetically, and because their models, with yolk vesicle and amniotic cavity, are more like human embryos.
These similarities may make these models more effective for research on miscarriage, genital malformatics and infertility, said James Briscoe of the Francis Crick Institute in London.
The structure created "seems to produce all the different types of cells that form tissues at this early stage of development," he said.
This study "is a step towards understanding a period of human development that leads to the failure of many pregnancies, and which has always been very difficult to study until now."
The researchers behind the study and other scientists insisted that the structures created should not be considered human embryos.
They "strongly resemble, but are not identical" to human embryos, the study said.
This and other recent work shows that "models of human embryos are becoming more sophisticated and closer to what can happen during normal development," said Darius Widera, a cell biology expert at the University of Reading.
The text stresses "that a robust regulatory framework is more necessary than ever", he insisted.
