Hairy2 genes control neural crest induction and cell migration in Xenopus embryos

GUILLERMO VEGA LÓPEZ; MARCELA BONANO; CELESTE TRÍBULO; MANUEL J. AYBAR

San Miguel de Tucuman

Congreso; XLV Reunión Anual de la Sociedad Argentina de Bioquímica y Biología Molecular; 2009

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Hairy2 genes control neural crest induction and cell migration in Xenopus embryos Guillermo Vega Lopez, Marcela Bonano, Celeste Tríbulo, Manuel J. Aybar Depto. Biol. Desarrollo, INSIBIO (CONICET-UNT), Chacabuco 461, 4000–S.M. Tucumán, Argentina.   It has been demonstrated that the yuxtacrine cell signaling pathway Notch/Delta is involved in the control of many developmental processes. Hairy genes encode transcription factors containing a bHLH DNA binding domain that are direct targets of Notch/Delta signaling in vertebrates and invertebrates. We have previously shown that Xenopus hairy genes (hairy1, hairy2a, and hairy2b) are expressed in the neural fold, the prospective neural crest (NC) region, from late gastrula stage onward suggesting that they have a role in neural crest induction and migration. In order to analyze the role of hairy genes during NC development by conditional gain- and loss-of-function, we have prepared chimeric inducible proteins. The overexpression of antisense oligonucleotides or chimeric inducible proteins and their dominant negatives by microinjection of in vitro transcribed mRNAs into developing embryos demonstrated that hairy genes are involved in the induction and migration of NC cells. The overexpression of hairy2a mRNA in naïve ectodermal tissue showed that this gene is able to induce neural crest markers. The transcriptional activity of the hairy2b gene was evaluated for a better understanding of the molecular mechanisms involved in the control of these developmental processes. Our results show that hairy genes are key players in the regulatory network controlling Xenopus NC development.