ESPE Yearbook of Paediatric Endocrinology

To read the full abstract: Development 2017;144:3278-3288

This article from Plazek’s laboratory describes a subpopulation of cells which express Fgf10 that are the precursors of the posterior pituitary gland. Importantly, these Fgf10 positive cells migrate rostrally to form the anterior hypothalamic region, but also migrate caudally to form the mammillary hypothalamic region. Cell lineage tracing using injection of DiI in the early stage embryos allows beautiful tracing of the cells evidence for the embryonic origin of these early hypothalamic regions. Previous studies have used mouse transgenes under a promoter that labels other embryonic tissues, not only the hypothalamic primordium, making these experiments difficult to interpret. Together with the studies from Martinez-Barbera’s laboratory, mentioned above (1.6) , this work shows that Fgf10 positive hypothalamic precursors cells respond to Shh signalling and that this is vital for their proliferation and maintenance. Hence, Shh is critical for infundibulum development and inhibition of Shh with cyclopamine inhibits infundibulum formation and leads to absence of RP.

Not many interventions lead to complete absence of the pituitary and therefore this study highlights a vital importance of Fgf10. Future work will reveal which cues trigger the migration of Fgf10+ve cells to form the anterior and mammillary hypothalamus and which genes are important in regulating this process. Such future studies may reveal new mechanisms important in the formation of the neuroendocrine hypothalamus and in turn endocrine homeostasis.