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[P156]: Cash1 is involved in specifying both the identity and number of first‐order relay sensory neurons in the developing chick hindbrain
Author(s) -
Mak K.,
Tumova K.,
Liu D.,
Logan C.
Publication year - 2006
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/j.ijdevneu.2006.09.216
Subject(s) - library science , order (exchange) , citation , identity (music) , hindbrain , computer science , psychology , art , neuroscience , finance , central nervous system , economics , aesthetics
Tumor suppressor genes function to ensure that appropriate cell numbers are maintained by differentiated organs and tissues. We have found that Zac1, a tumor suppressor gene encoding a zinc finger transcription factor, functions similarly during development to negatively regulate cell number. Zac1 mutants develop hypercellular retinae containing supernumerary amacrine cells that form an ectopic cellular layer without gross effects on other cell populations. Expansion of the amacrine cell population correlates with a late, stage-specific increase in proliferation while conversely, Zac1 misexpression efficiently promotes cell cycle exit. However, our misexpression studies indicate that Zac1 is not a direct negative regulator of amacrine cell genesis. Instead, we found that Zac1 modulates amacrine cell numbers non-autonomously by controlling the emission of a negative feedback signal from differentiated amacrine cells. We are currently investigating the molecular nature of the amacrine cell feedback signal, and have preliminary evidence that inhibition of PI3K signalling can phenocopy the amacrine cell expansion observed in Zac1 mutants. The results of these investigations will be presented.