Relevance: GS-3: Science and Technology- developments and their applications and effects in everyday life.
Key Phrases: Synthetic embryos, Fertilization, Stem cells, Tissues, Specialized cells, Embryonic stem cells, Adult stem cells, Bone marrow, Blood cells, Infertility, IVF, Contraceptives, disease, Organs, Organoids, New Drugs and Clinical Trial Rules, 2019.
Context:
- Melbourne, Aug 7, biologists have grown mouse embryo models in the lab without the need for fertilised eggs, embryos, or even a mouse – using only stem cells and a special incubator.
- This achievement, published in the journal Cell by a team led by researchers from the Weizmann Institute of Science in Israel, is a very sophisticated model of what happens during early mouse embryo development - in the stage just after implantation.
What are Synthetic embryos?
- Synthetic embryos are embryos, which are created without fertilization.
- Such embryos (also known as artificial embryos) do not require an egg or sperm cell to facilitate their creation. Instead, these embryos rely on self-assembling stem cell structures to mimic the natural process of early human development.
- Currently, synthetic embryos were 95% equivalent to real mouse embryos in terms of internal structure and cell genetic profiles.
Embryo
- An embryo is the early stage of the development of a multicellular organism.
- In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after the fertilization of the female egg cell by the male sperm cell.
- The resulting fusion of these two cells produces a single-celled zygote that undergoes many cell divisions that make cells known as blastomeres.
- In humans, an embryo is a term applied to the unborn child until the end of the seventh week following conception; from the eighth week, the unborn child is called a fetus.
- In other multicellular organisms, the word "embryo" can be used more broadly to describe any early developmental or life cycle stage before birth or hatching.
What are stem cells?
- Stem cells are special human cells that are able to develop into many different cell types.
- They can range from muscle cells to brain cells.
- In some cases, they can also fix damaged tissues.
- Under the right conditions in the body or a laboratory, stem cells divide to form more cells called daughter cells.
- These daughter cells become either new stem cells or specialized cells (differentiation) with a more specific function, such as blood cells, brain cells, heart muscle cells or bone cells.
- No other cell in the body has the natural ability to generate new cell types.
Where do stem cells come from?
There are several sources of stem cells:
- Embryonic stem cells:
- These stem cells come from embryos that are 3 to 5 days old. At this stage, an embryo is called a blastocyst and has about 150 cells.
- These are pluripotent stem cells, meaning they can divide into more stem cells or can become any type of cell in the body.
- This versatility allows embryonic stem cells to be used to regenerate or repair diseased tissue and organs.
- Adult stem cells:
- These stem cells are found in small numbers in most adult tissues, such as bone marrow or fat.
- Compared with embryonic stem cells, adult stem cells have a more limited ability to give rise to various cells of the body.
- Adult stem cells are multipotent. It means they can develop only into closely related cell types.
- For instance, researchers thought that stem cells residing in the bone marrow could give rise only to blood cells.
Why model embryos is Important?
Embryo models could improve health in five ways. Like.
- Treating infertility:
- It is thought that at least 40% of pregnancies fail by 20 weeks and that 70% of those that fail to do so at implantation.
- Embryo models could give researchers a better understanding of implantation and gastrulation, and lead to better infertility treatments.
- Improving In vitro fertilization:
- Only around 20% of IVF procedures result in a birth.
- Using stem-cell models, researchers could optimize implantation and minimize cellular abnormalities, such as an aberrant number of chromosomes. As well as safeguarding the health of children conceived in vitro, this could reduce the number of procedures.
- Designing new contraceptives:
- Embryo-model work could improve drugs that prevent implantation (as the oral contraceptive pill or intrauterine devices do, in part).
- Women and health professionals need drugs and devices that are easier to use and that have fewer side effects.
- Preventing disease:
- Subtle cell abnormalities can alter development of the placenta and restrict embryo growth, affecting the baby’s birth weight and propensity for chronic diseases (such as those of the heart) decades later.
- Entities based on stem cells could help researchers to pinpoint the genetic and epigenetic changes involved, and assess the effects of diets or drugs.
- Creating organs:
- Mini brains, livers, kidneys and other organoids made from stem cells are highly simplified.
Do you know?
- In March 2019, the Union Health Ministry notified the ‘New Drugs and Clinical Trial Rules, 2019’, which state that stem-cell-derived products are to be used as “new drugs”. This means that any doctor who uses stem cell therapy needs to take permission from the government.
- In India as well as globally, only blood stem cells from bone marrow to treat blood cancers and different blood disorders are permitted. The clinical use in any other disease or use of any stem cells other than these is still in the research stage.
Source: The Hindu BL
Mains Question:
Q. What are the stem cells? What is the difference between Adult stem cells and Embryonic stem cells? (250 Words).
