The human has long experimented with creating embryos of animals with human stem cells. They are called “humaniamal” or chimeras, as hybrids between animals and humans were known in ancient Greece. But this is the first time that a government expressly supports it.
The Japanese government last March gave the green light so that the scientist Hiromitsu Nakauchi, who leads research groups at the University of Tokyo (Japan) and Stanford (United States) can develop human organs in animals from human stem cells.
The idea is not a pioneer, but this is the first time a government supports such experiments, according to the journal Nature.
Even before in the United States and other countries, attempts were made to grow human cells in mouse, rat and even sheep embryos and then transplant those embryos into substitute animals.
In all cases, however, the experiments were interrupted, whether due to legal obstacles or lack of success of the trial.
La idea es experimentar en ratas y ratones para que desarrollen órganos humanos que después puedan ser trasplantados. Pero no todos ven con buenos ojos este tipo de ensayos… https://t.co/rhFt9QAbyb— BBC News Mundo (@bbcmundo) July 31, 2019
The Japanese government drives the chimaera of the humanimals
In March, after a request from the Nakauchi team, the Japanese Ministry of Education and Science issued new guidelines around research with stem cells that allow the creation of human-animal embryos that can be transplanted into substitute animals and also take them I finish it.
The final decision, in any case, depends on a committee of experts from the Ministry of Science and will be announced this August.
The controversy of stem cells
But the process will be slow and not without obstacles: scientific and ethical.
Experiments with stem cells are, in many cases, a cause of controversy. Bioethicists are concerned that human cells reach the developing brain of the animal, affecting their cognitive abilities.
Japón aprueba crear animales con órganos humanos. Algunos bioéticos opinan que sería un problema la migración de células al cerebro de los animales, afectando su capacidad de conocer; se olvida que el conocer no está producido por las neuronas: https://t.co/JtTvdqP0Iq pic.twitter.com/GcbQtaevIH— Material de bioética (@mbioetica) July 31, 2019
Nakuchi argues that the experiment is designed so that “stem cells only go to the pancreas.” This will not attempt to transplant any hybrid embryo, but will first cultivate embryos of hybrid mice for a period of about 14 days, when almost all of the animal’s organs are formed.
Then he will do the same in rats, letting them develop up to 15 days and later he will do it with pigs.
But still, not everyone is convinced by the plans of the Japanese scientist.
The researcher Jun Wu, from the University of Texas (United States), says it is useless to carry out human-animal hybrid embryos using evolutionarily distant species such as pigs and sheep because “human cells will be eliminated in the initial phase of the experiment.”
Just this week, the Spanish newspaper El País publishes the progress of the work of a group of Spanish scientists who claim to have created human and monkey chimeras in China.
Many of the details remain to be known until the result of the experiment is published shortly in an international scientific journal that was not disclosed.
Source: BBC Mundo