April 2021 Pulse
Researchers have successfully developed and grown model versions of very early human embryos or blastocyst by ‘re-programming’ stem cells taken from adults. Scientists believe that this very significant breakthrough would enable them to study the earliest stages of human development in ways that were not possible before. They hope that this research will in turn generate new insights on developmental disorders, infertility and genetic diseases.
Jose Polo and his team of scientists at Monash University were studying how induced pluripotent stem cells (iPS cells), which are derived from adult skin or blood cells, can be reprogrammed into any human cell. In the process, they discovered that some cells (about two percent) activated genes that are seen in very early stages of embryogenesis, the immediate period after the egg is fertilised by the sperm.
Polo and his team called these cell balls iBlastoids because they resemble the blastocyst. ‘To determine the true nature of these structures,’ the scientists report, ‘we performed a battery of molecular and functional assays. These assays demonstrated that the structures were blastocyst-like structures that could model several aspects of blastocyst biology.’
iBlastoids, however, lack the normal membrane that surrounds the blastocyst called the zona pellucida. This means that iBlastoids are unable to develop into foetuses on their own.
Even though the ‘primitive endoderm’ is not well defined in the iBlastoid, scientists believe that the discovery is still very significant. As Polo explains: ‘This discovery is still really important; even if they are a model and not the exact thing, they will provide valuable data when it comes to finding out more about why miscarriage occurs, and perhaps point to causes of infertility.’
Cosmos reports that many scientists working in the field agree with Polo about the significance of this disocvery and its potential contribution to their understanding of early human development.
Dr Peter Rugg-Gunn of the Babraham Institute in Cambridge, UK, believes that this discovery provides ‘an exciting advance by describing the conditions to engineer human blastocyst-like structures in the laboratory … the next steps of the research will be to optimise the conditions to improve the efficacy of forming the blastocyst-like structures.’
Professor Megan Munrise, the Director of the University of Melbourne’s Centre for Stem Cells Systems, sees this development as opening the way for a better understanding of the role of fertility, miscarriages and the effects of drugs on early human embryos. But the success of subsequent research, she points out, would depend on the consistency of producing such models. With only 1 successful outcome in every 10 attempts, the current success rates have been dismal.
While there are a number of ethical concerns surrounding the creation of the iBlastoid, for the Christian ethicist the fundamental question has to do with its moral status.
Christians believe that human life begins at conception, that is, when the sperm fertilises the egg. Christians maintain that all human beings, at every stage of their biological development, must be accorded dignity and value and are deserving of protection because they are created in the image and likeness of God (Genesis 1:26-27).
Because the iBlastoid resembles the blastocyst, which is the earliest form of a human being, its moral status is an important issue that should not be ignored.
In their article entitled ‘Modelling Human Blastocysts by Reprogramming Fibroblasts into iBlastoids’ published in Nature (March, 2021), Jose Polo and his colleagues describe the iBlastoid in this way:
[iBlastoids] model the overall architecture of blastocysts, presenting an inner cell mass-like structure, with epiblast- and primitive endoderm-like cells, a blastocoel-like cavity, and a trophectoderm-like outer layers. Single-cell transcriptomics further confirmed the presence of epiblast-, primitive endoderm-, and trophectorderm-like cells. Moreover, iBlastoids can give rise to pluripotent and trophoblast stem cells and are capable of modeling, in vitro, several aspects of the early stage of implantation.
In other words, the iBlastoid has the overall genetics and architecture of a human blastocyst, even though it is not completely identical with it.
‘Early blastocysts’ Polo explains, ‘are enclosed within the zona pellucida, a membrane derived from the egg that interacts with sperm during the fertilisation process and later disappears. As iBlastoids are derived from adult fibroblasts, they do not possess a zona pellucida.’
Based on this account, however, is it inconceivable to regard the iBlastoid as a human being, albeit a severely disabled one? And if that is in fact what it is, then should not the question of its moral status give us pause?
In his article on the iBlastoid, Julian Savulescu, Director of the Oxford Uehiro Centre for Practical Ethics, maintains that ‘since these structures (iBlastoids) cannot produce a live born baby, they appear not to be embryos on the common-sense definition of the term.’
Savulescu thinks that it is philosophically absurd to describe iBlastoids as embryos. If iBlastoids are embryos, he reasons, skin cells would also be embryos. This is because ‘skins cells can produce an iBlastoid if they are reprogrammed, and iBlastoids are embryos.’
Put differently, Savulescu’s argument is if iBlastoids are embryos, skin cells should also be regarded as embryos since iBlastoids are created from them. Since no one would regard skin cells as embryos, so the logic goes, it is also absurd to regard the iBlastoid as an embryo.
Professor Savulescu’s argument, however, is fundamentally flawed.
Skin cells cannot be regarded as embryos because left on their own they will never articulate into embryos. It is only due to the intervention of scientists that these cells develop in a way that they would never otherwise (naturally) do so.
Once the iBlastoid is created, however, we have an organism that resembles the blastocyst in almost every way except for the absence of the zona pellucida, as we have seen. If that membrane is added, the iBlastoid could theoretically be implanted into the uterus of a woman, where it would develop into a foetus.
Just because the iBlastoid lacks the zona pellucida does not disqualify it from being a human blastocyst. As Archbishop Anthony Fisher — himself a bioethicist — has correctly argued:
Nature already provides for a significant variance in early human development. Those human embryos that do not develop exactly as expected because of some chromosomal abnormality or other genetic issues are still embryonic human beings, and it would be outrageous for anyone to suggest these were not human, just because their development did not appear ‘normal’. Until we know for certain, we must give these embryonic human beings the benefit of the doubt.
It must also be pointed out that the labels that scientists have attached to the organism can also divert attention away from the hard questions about its true nature and therefore its moral status. As Archbishop Fisher has perceptively put it, ‘Is this label just a matter of convenience, masking legitimate questions about their identity and making them sound like the latest Apple product and less than a human being worthy of respect and protection?’
It is therefore not unreasonable to consider the possibility that this ball of cells that scientists have created by re-programming pluripotent cells taken from human skin is in fact a severely malformed human blastocyst.
And if that is indeed the case, then Christians should strenuously object to the creation of the iBlastoid. For its creation would be tantamount to deliberately bringing into being seriously deformed and disabled human beings so that they can be used for research and subsequently destroyed and discarded.
Dr Roland Chia is Chew Hock Hin Professor at Trinity Theological College (Singapore) and Theological and Research Advisor of the Ethos Institute for Public Christianity.