Cellular differentiation occurs in the human fetal pituitary between the eighth and sixteenth weeks of gestation. As early as 9 weeks of gestation, Pavlova et al.

At which stage does cell differentiation start?

During the third week after fertilization, the embryo begins to undergo cellular differentiation. Differentiation is the process by which unspecialized cells become specialized. As illustrated in Figure below, differentiation occurs as certain genes are expressed ("switched on") while other genes are switched off.

How do cells differentiate during development?

Cell differentiation is how generic embryonic cells become specialized cells. This occurs through a process called gene expression. ... During cell differentiation, the cell size and shape changes dramatically, as does its ability to respond to signaling molecules.