Differentiation of cell types from non-neurogenic placodes
Schlosser, Gerhard
Schlosser, Gerhard
Loading...
Repository DOI
Publication Date
2021-06-18
Keywords
Type
book part
Downloads
Citation
Schlosser, Gerhard. (2021). Differentiation of cell types from non-neurogenic placodes. In Gerhard Schlosser, Development of sensory and neurosecretory cell types: Vertebrate cranial placodes, Volume 1. Boca Raton: CRC Press.
Abstract
Chapter 8 reviews how cell types derived from the non-neurogenic placodea, i.e. the lens and adenohypophyseal placodes, differentiate. The lens placode gives rise to lens fiber cells, which are rendered transparent by the accumulation of crystallin proteins. They are specified by a core regulatory network (CoRN) of Pax6, FoxE3, SoxB1 together with proteins of the large Maf family. Because some large Mafs also are essential for the specification of retinal photoreceptors and crystallins are also expressed in photoreceptors (where they have a neuroprotective effect), it is proposed that lens fiber cells may have evolved from ciliary photoreceptors. The adenohypophyseal placode generates the neurosecretory cells of the anterior pituitary. These produce hormones belonging to three different families (peptide hormones, dimeric glycoprotein hormones and four-helix cytokine-like proteins). While Pitx1/2 and Lhx3/4 are important members of the CoRN regulating the specification of all types of neurosecretory cells in the anterior pituitary, additional transcription factors are required in defining the different subtypes of neurosecretory cells. Comparative studies suggest that three subtypes of neurosecretory cells were probably present at the base of vertebrates, each dedicated to the production of one hormone class. Subsequently, subtypes diversified further into the six neurosecretory cell types found in gnathostomes.
Funder
Publisher
CRC Press
Publisher DOI
https://doi.org/10.1201/9781315162317
Rights
Attribution-NonCommercial-NoDerivatives 4.0 International