What are the stages of cell differentiation?

Cell differentiation involves three main stages: commitment, specification, and terminal differentiation.

Cell differentiation is a process where a cell changes from one type to another, more specialised type. This process is crucial in the development of an organism, allowing it to grow from a single fertilised egg into a complex system of different cell types, tissues, and organs.

The first stage of cell differentiation is commitment. During this stage, a cell is 'committed' to becoming a certain type of cell. This commitment is often a response to signals from other cells, and once a cell has committed to a certain path, it cannot change its decision. However, at this stage, the cell has not yet changed in any visible way. It is still a 'blank slate', but it has made a decision about what type of cell it will become.

The second stage is specification. During this stage, the cell begins to acquire the properties of the cell type it has committed to becoming. This involves changes in the cell's gene expression, which in turn lead to changes in the proteins the cell produces. These changes are still reversible at this stage, but as the cell continues to differentiate, it becomes more and more specialised and less able to change its path.

The final stage is terminal differentiation. At this point, the cell has fully become the type of cell it committed to becoming. It has all the characteristics of that cell type, and it can no longer change into a different type of cell. This is the stage at which the cell begins to perform its specialised function in the body.

In summary, cell differentiation is a process of commitment, specification, and terminal differentiation. Each stage is crucial in the development of an organism, allowing it to grow and function properly.