Why is that during somatic cell nuclear transfer the embryo is never implanted into the uterus?
Never is a powerful word. Wasn't Dolly the sheep created this way?
Maybe I ought to add to this. We live in a world that under social and legal mores we reproduce things from gametes, in fact, in many places, including Texas, it is illegal (and some say immoral) to reproduce with cells other than gametes. So placing the somatic cell nucleus into the uterus will be akin to "creating" life, which is illegal. Yes, Dolly the sheep was cloned this way, but not in Texas.
During somatic cell nuclear transfer (SCNT), the nucleus of a somatic cell (body cell) is transferred into an unfertilized egg cell, leading to the creation of an embryo that is genetically identical to the somatic cell donor. However, in most cases, the embryos created through SCNT are not implanted into the uterus for several reasons:
1. Experimental Stage: SCNT is primarily performed for research purposes and is still in the experimental stage. The main objective is to study and understand the genetic and cellular processes involved in cloning and stem cell research.
2. Developmental Issues: The embryos created through SCNT often demonstrate abnormalities and developmental issues. These abnormalities may result from errors during the reprogramming process or from the age of the somatic cell donor. As a result, most SCNT embryos are not suitable for implantation and further development.
3. Ethical Concerns: The use of SCNT for reproductive purposes raises ethical dilemmas and controversies. The cloning of humans is widely considered ethically unacceptable due to concerns about genetic abnormalities, identity, and potential exploitation. As a result, implanting SCNT embryos into a uterus for reproductive purposes is a highly debated topic.
It's important to note that SCNT research has contributed to advancements in various fields, such as regenerative medicine and animal cloning. However, due to the reasons mentioned above, the embryos created through SCNT are generally not implanted into the uterus.