During development of different tissues, there are pools of progenitor cells from which different cell types are formed. The mechanisms regulating how cell fate is determined are not completely understood, but a paper earlier this year helps to clarify this process in the developing retina. The authors identify a role for Blimp1, a transcription factor, in regulating the cell fate decision of the progenitor cells. Image shows retinal tissue from mice with (left) and without (right) Blimp1, after the cells have undergone differentiation into the different cell types. Without Blimp1, retinas had a thinner outer layer (bracket) and a thicker inner layer, as well as incorrect numbers of certain cells (red cells).
Reference: Joseph A. Brzezinski IV, Deepak A. Lamba and Thomas A. Reh, 2010. Development: 137, 619-629. doi: 10.1242/dev.043968. Adapted with permission by Development. Paper can be found here.