Chimera Research: Human Cells in Monkey Embryos

• 21 Apr 2021

Why in News

Recently, researchers at the Salk Institute for Biological Studies in the US in a research called Chimera Research have for the first time grown human cells in monkey embryos.

Key Points

• About the Research:
  
  • By integrating human cells into the embryos of macaque monkeys, a chimeric tool has been created.
    
    • Chimeras are organisms that are made up of the cells of two distinct species, in this case humans and monkeys.
    • For instance, if this hybrid embryo was placed in the womb of a monkey, it could possibly grow into a new kind of an animal (however this was not the aim of this study).
• Purpose of the Research:
  
  • Understanding Human Development & Drug Evaluation:
    
    • Ability to grow cells of two different species together offers scientists a powerful tool for research and medicine, advancing current understanding about early human development, disease onset and progression and ageing.
    • It could also help in drug evaluation and address the critical need for organ transplantation.
  • Provides New Platform to Study Diseases:
    
    • Chimeric tools provide a new platform to study how certain diseases arise. For instance, a particular gene that is associated with a certain type of cancer could be engineered in a human cell.
    • It can help in studying the course of disease progression using the engineered cells in a chimeric model, which may be able to tell them more about the disease than results obtained from an animal model.
• Reason for Choosing Macaque:
  
  • In a 2017 study, researchers integrated human cells into pig tissues as they thought that pigs, whose organ size, physiology and anatomy are similar to that of humans, could help them in creating organs that could ultimately be transplanted to humans.
  • As the experiment failed due to evolutionary distance between pigs and humans (about 90 million years) the researchers decided to pick a species that was more closely related to humans, hence macaque monkeys were chosen.
• Concerns:
  
  • Not Natural and have Survival Issue:
    
    • Some rare hybrid animals exist naturally and were probably the result of unintentional cross breeding between animals of different species.
      
      • In 2014, a rare hybrid animal called Geep (Goat+Sheep) was born in an Irish farm. Geep was a hybrid between a goat and a sheep, a result of the two mating.
      • Generally, different species don’t cross-breed and if they do, their offspring don’t survive for long and are prone to infertility.
  • Infertility:
    
    • Mules are another example of a hybrid animal that are the result of mating between a female horse and a male donkey.
      
      • As per the American Mule Museum, these hybrid animals are the result of intentional breeding by humans, which they first undertook in the ancient times.
    • While mules can live a long healthy life, they are infertile which means that they cannot have offspring of their own.
  • Injustice Against Animals for Human Benefit:
    
    • Although researchers have made it clear that the chimeras created with macaques will not be used for human organs still there is skepticism since others feel that one of the goals of chimera research is to create organs that can be transplanted to humans.
    • Chimera research has the potential to worsen injustice against animals and also point out the fairness in using part-human animals to meet human needs.
      
      • In 2018 a scientist in China claimed to have produced genetically modified babies using the gene editing technique CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats). He was sentenced to prison for three years, with a fine of 3 million yuan (approx. Rs 3 crore), for illegal medical practice.
• Indian Laws on Hybrid Animals:
  
  • In India production of hybrid animals has been banned since 1985..
  • Genetically Modified Organisms (GMOs) and the products are regulated under the “Rules for the manufacture, use, import, export & storage of hazardous microorganisms, genetically engineered organisms or cells, 1989” (referred to as Rules, 1989) notified under the Environment (Protection) Act, 1986.
    
    • These Rules are implemented by the Ministry of Environment, Forest and Climate Change, Department of Biotechnology and State Governments though six competent authorities.
    • The Rules, 1989 are supported by a series of guidelines on contained research, biologics, confined field trials, food safety assessment, environmental risk assessment etc.

Way Forward

• Genetic modification like chimera studies continues to be a subject of major debate. In developing countries like India, genetically modified crops are also a contentious topic.
• Tampering with the genetic code in human beings is more controversial, as any such change can be passed down to future generations.

Source: IE