Initiation and maintenance of neuronal terminal differentiation programs.

Contributions of chondrogenesis and endochondral ossification to adult limb proportions in two mammals with different modes of locomotion, the house mouse (top, Mus musculus) and Seba's short‐tailed bat (bottom, Carollia perspicillata). In early development, embryos are similar in size, though the bat hand plate (blue) is already larger than in the mouse. At matching fetal stages, the bat has a markedly longer third metacarpal (MC3, blue). The rapid fetal and postnatal elongation of the bat's MC3 is then driven by its growth plate chondrocytes, which are (a) more numerous, (b) dividing more frequently (black cells), and (c) hypertrophying to a much greater extent than in the mouse. Species differences in these three cellular parameters are the main drivers of diversity in mammalian limb bone size and shape. Bat embryo/fetus redrawn from Cretekos et al. (2005), adult bat skeleton redrawn from Cooper et al. (2012), with permission.

The septal nuclei arise from different progenitor domains during development. Abbreviations: ChAT, choline acetyl transferase; LGE, lateral ganglionic eminence; MGE, medial ganglionic eminence; POA, pre optic area; PSB, pallial sub pallial boundary; Sep NE, septal neuroepithelium; SEP, septum; TE, thalamic eminence; vGlut2, vesicular glutamate transporter 2.