A somatic cell (from the Ancient Greek sôma, meaning “body”), or vegetal cell, is any biological cell other than a gamete, germ cell, gametocyte, or undifferentiated stem cell that forms the body of a multicellular creature. The somatic cell is a cell that contributes to the makeup of an organism’s body and divides via binary fission and mitotic division.

By contrast, gametes are cells that merge during sexual reproduction, germ cells are cells that produce gametes, and stem cells are cells that can divide by mitosis and differentiate into a variety of specialised cell types. For instance, in mammals, somatic cells comprise all internal organs, skin, bones, blood, and connective tissue, whereas mammalian germ cells generate spermatozoa and ova, which combine during fertilisation to form a cell termed a zygote, which divides and differentiates into embryonic cells. The human body has roughly 220 different types of somatic cells. 

These cells are not germ cells (which produce gametes); they transfer their mutations to their cellular offspring (if any), but not to the organism’s descendants. However, non-differentiated somatic cells form the germ line in sponges, whereas developed somatic cells form the germ line in Cnidaria. Only diploid somatic cells undergo mitotic cell division. Only a few cells, such as germ cells, participate in reproduction. 

Somatic cell nuclear transfer

Somatic cell nuclear transfer (SCNT) is a technique used in genetics and developmental biology for producing a healthy embryo from a body cell and an egg cell. The procedure involves removing the nucleus from an enucleated oocyte (egg cell) and implanting it with a donor nucleus from a somatic (body) cell. It is employed in both reproductive and therapeutic cloning. Dolly the sheep gained notoriety in 1996 as the first successful case of mammalian reproductive cloning: In January 2018, a Shanghai-based team of scientists announced the successful cloning of two female crab-eating macaques (dubbed Zhong Zhong and Hua Hua) from foetal nuclei. 

The term “therapeutic cloning” refers to the potential use of SCNT in regenerative medicine; this approach has been promoted as a solution to the numerous issues surrounding embryonic stem cells (ESCs) and the destruction of viable embryos for medical purposes, though questions remain about the true homology between the two cell types.

Process

1. Two distinct cells are involved in the process of somatic cell nuclear transfer. The first type of gamete is a female gamete called an ovum (egg/oocyte). 
2. In human SCNT research, these eggs are obtained via ovarian stimulation from consenting donors. 
3. The second is a somatic cell, which refers to the human body’s cells. Only a few examples include skin cells, fat cells, and liver cells. The donor egg cell’s genetic material is extracted and discarded, leaving it ‘deprogrammed.’ Only a somatic cell and an enucleated egg cell remain. The somatic cell is subsequently inserted into the ’empty’ ovum and fused. 
4. The somatic cell nucleus is reprogrammed by its host egg cell after it is introduced into the egg. The ovum, which now contains the nucleus of the somatic cell, is activated with a shock and begins to divide. 
5. The egg is now viable and capable of developing into an adult creature with all necessary genetic information from a single parent.
6.  The single cell will continue to develop properly, and after numerous mitotic divisions, it will produce a blastocyst (an early-stage embryo with approximately 100 cells) with the same genome as the original organism (i.e., a clone). 
7. Stem cells can then be obtained by either destroying the clone embryo for use in therapeutic cloning or by implanting the clone embryo into a host woman for further development and bringing it to term in the event of reproductive cloning.

Reproductive cloning

This technology is being used to clone animals (such as the infamous Dolly the sheep) and has been proposed as a method for cloning humans. SCNT has shown to be challenging to use in reproductive cloning, with minimal success. The high rate of fetal and neonatal death renders the process ineffective. In non-human species, the cloned offspring also exhibit developmental and imprinting abnormalities. 

For these reasons, as well as moral and ethical concerns, over 30 countries have prohibited human reproductive cloning. The majority of researchers feel that it will be impossible to create a human clone that will develop to term with the present cloning process in the foreseeable future. It is still a possibility, albeit significant changes will be necessary to overcome present restrictions in human SCNT embryonic development.

Additionally, there is the possibility of curing disorders related with mitochondrial DNA abnormalities. Recent research indicates that SCNT of the nucleus of a body cell infected with one of these disorders into a healthy egg prevents the mitochondrial disease from being inherited. This is not a cloning procedure, but it would result in a child with three genetic parents. A father contributes a sperm cell, one mother contributes an egg nucleus, and another mother contributes an enucleated egg cell.

Somatic cell division

Somatic cell division is the process through which a parent cell divides into daughter cells that are identical to the parent cell. They contain the same number of chromosomes as the parent cell. Mitosis occurs in all of the body’s somatic cells. The stages of mitosis are as follows:

1. Prophase: This phase is characterised by the disappearance of the nuclear membrane and the appearance of chromosomes. Centrioles migrate to the opposing corners and the production of spindle fibres begins.
2. Metaphase: The chromosomes align in the cell’s centre, establishing the equatorial plate. Spindle fibres that connect the chromosomes’ centromeres.
3. Anaphase: During this phase, spindle fibres are retracted and chromosomes’ sister chromatids are separated and moved to opposing ends of the cell.
4. Telophase: The nuclear membrane re-emerges around the chromosomes on both ends, resulting in the presence of two nuclei at the end of this phase.
5. Cytokinesis: The cell divides into two daughter cells, each of which has one nucleus.

Conclusion 

A somatic cell is any cell in the body that is not sperm or egg. Diploid somatic cells contain two sets of chromosomes, one inherited from each parent. Individuals can be affected by somatic cell mutations, but they are not passed onto offspring. Somatic cell division is the type of cell division where the daughter cells are just like the parent cell. This means that they have the same chromosome number as that of their parent cell. Every cell in the body that is made of tissue goes through mitosis. Somatic cell nuclear transfer (SCNT) is a technique used in genetics and developmental biology for producing a healthy embryo from a body cell and an egg cell.