differentiation & embryogenesis

Cellular differentiation commits cells to clusters of activities specific to distinct cell lines and tissues.

In cellular reproduction, DNA replication and cell division are coordinated such that the distribution of new DNA copies to each daughter cell is ensured. Differentiation into distinct tissue types in multicellular organisms requires regulated timing of the location and expression of specific genes, such that initially totipotent (all lines - zygotes, early embryonic cells), and subsequently pluripotent (many lines – stem, meristematic) cells become committed to the characteristics of single cell lines. Differentiation involves alterations in numerous aspects of cell physiology such that structure and polarity are determined, while metabolic activity, responsiveness to signals, and gene expression are variably regulated.