All somatic cells originate from the mitosis of a zygote and contain the same 46 chromosomes, yet they exhibit distinct characteristics due to differential gene expression. Cellular differentiation is the process that enables less specialized cells to become specialized cell types, influenced by which genes are activated or silenced. For instance, eye cells express genes relevant to vision while heart cells express genes necessary for cardiac function. This differentiation process continues throughout adulthood, particularly during tissue repair and normal cell turnover, without altering the underlying DNA sequence.
PREREQUISITESStudents and professionals in biology, particularly those focused on developmental biology, genetics, and regenerative medicine, will benefit from this discussion.
In developmental biology, cellular differentiation is the process by which a less specialized cell becomes a more specialized cell type. Differentiation occurs numerous times during the development of a multicellular organism as the organism changes from a simplezygote to a complex system of tissues and cell types. Differentiation continues in adulthood as adult stem cells divide and create fully differentiated daughter cells during tissue repair and during normal cell turnover. Differentiation dramatically changes a cell's size, shape, membrane potential, metabolic activity, and responsiveness to signals. These changes are largely due to highly controlled modifications in gene expression. With a few exceptions, cellular differentiation almost never involves a change in the DNA sequence itself. Thus, different cells can have very different physical characteristics despite having the same genome.