HUMAN EMBRYO
WHY IN NEWS ?
- Recently, Scientists have successfully grown a “human embryo” in the lab without using an egg or sperm.
MORE ABOUT THE NEWS :
- As scientists have successfully grown a “human embryo” in the lab without using an egg or sperm.
- They used a mix of stem cells — early cells that have the ability to differentiate into other types of cells .
- That was able to spontaneously assemble into an embryo-like structure, mimicking molecular characteristics of an early embryo.
ABOUT NEW EMBRYO MODEL :
- The scientists have called it one of the most complete models of a 14-day-old human embryo.
- Several teams have been working on developing these human embryo-like models — around six such models have been published this year itself.
- None of them fully replicate the processes that happen during the early stages of embryo development, but all of them add to their understanding.
- The researchers from Israel used a mix of stem cells and chemicals.
- A small portion of which was able to spontaneously assemble to form different types of cells that form the foetus, those that provide nutrients to the foetus.
- Also led to formation of cells that lay out the plan for development of the body, and cells that create structures like placenta and umbilical cord to support the foetus.
- One of the problems that the team faced, however, was that only 1% of this mixture actually assembled spontaneously, making the process not very efficient.
IMORTANCE OF NEW EMBRYO MODEL AND RESEARCH :
- Embryonic research is very important because currently one of the only ways of studying these early processes is through developing alternative models that can be grown in the lab.
- Although they mimic several aspects of development, they are not surrogates of actual embryos.
- There is no way for scientists to ethically research the early stages of development of an embryo, as it is difficult to study it after it implants in the uterus.
- Scientists currently study these initial changes in various lab models or donated embryos.
- This research is crucial because the initial days of embryo development is when the majority of miscarriages and birth defects occur.
- Studying the initial stages, scientists say, may help understand genetic and inherited diseases better.
- The understanding of why some embryos develop normally, retain the proper genetic code, and implant properly in the womb while others do not, may also help in improving success rates of in vitro fertilisation.
- Scientists are slowly mimicking the organisation of cells as seen in real embryos.
- This will led us closer to understanding how genetic defects lead to certain diseases or how futuristic genetic medicines can be implemented for the treatment of certain conditions.
CAN LAB GROWN EMBRYOS BE USED TO GET PREGNANT ?
- These models are only meant to study the early stages of development of a foetus. Thus they cannot be used to get pregnant.
- It is generally accepted — and legally supported in most countries — that these embryo models will be destroyed after studying the first 14 days.
- Attempts to implant are not allowed.
- Also, creating a lab-based model that mimics the properties of early embryos is still far from an actual embryo that can implant to the lining of the womb.
WHAT IS 14-DAY LIMIT ON EMBRYO RESEARCH ?
- The limit was first proposed by a committee in the UK in 1979 after the birth of the first test tube baby Louise Brown demonstrated that embryos could be kept alive in laboratories.
- The 14-day period is equivalent to when embryos naturally finish implantation.
- It is also when cells start becoming an “individual”, and breaking off into a twin is not possible.
- The ethical considerations become different when it is a clump of cells and when it becomes an individual, often related to what is referred to as the Primitive Streak.
- While the models are not human embryos, they come very close to it.
- Primitive Streak is a linear structure that appears in the embryo that marks its transition from having a radial symmetry (like an egg) to the bilateral symmetry of our bodies (marked by left and right hands and legs).
WAY FORWARD:
- These models allow scientists to see what roles various genes play in the development of the foetus.
- This exciting development allows us to manipulate genes to understand their developmental roles in a model system.
- This will let us test the function of specific factors, which is difficult to do in the natural embryo.
SYLLABUS: MAINS, GS-3, SCIENCE AND TECHNOLOGY
SOURCE: INDIAN EXPRESS
