Banded hedgehog and Gli intracellular factors control

AGUERO T.; VEGA LOPEZ G.; SÁNCHEZ S. S.; AYBAR M. J.

University of Michigan, USA

Congreso; 65th Annual Meeting Society for Developmental Biology; 2006

SBD

Secreted morphogens of the Hedgehog (Hh) family in Xenopus are Sonic hedgehog, Cephalic hedgehog, and Banded hedgehog. They regulate a wide range of developmental processes such as nervous system and limb patterning. In this work, we revised the expression pattern of Banded hedgehog (Bhh) and components of the intracellular signaling cascade during early development of Xenopus laevis embryos. The double in situ hybridization analysis showed that Bhh is expressed during neurulation at the lateral border of neural plate in territories that overlap with the expression of Gli transcription factors and neural crest markers. In order to evaluate the participation of Bhh pathway in neural crest development, we carried out gain- and loss-of-function approaches by directed microinjection of Bhh mRNA, its dominant-negative and morpholino oligonucleotides. Results showed that the overexpression of Bhh leads to an increased expression of neural crest markers and Gli transcription factors. On the other hand, the dominant-negative construct of Bhh and the morpholino oligonucleotide reduced the expression of neural crest markers, indicating Bhh signaling is required for neural crest specification. Additionally, the overexpression of Gli3 produced an expansion in neural crest territory mimicking the effect produced by Bhh gain of function. Our results show that Bhh signaling and Gli transcription factors are participating in the early neural crest development Xenopus are Sonic hedgehog, Cephalic hedgehog, and Banded hedgehog. They regulate a wide range of developmental processes such as nervous system and limb patterning. In this work, we revised the expression pattern of Banded hedgehog (Bhh) and components of the intracellular signaling cascade during early development of Xenopus laevis embryos. The double in situ hybridization analysis showed that Bhh is expressed during neurulation at the lateral border of neural plate in territories that overlap with the expression of Gli transcription factors and neural crest markers. In order to evaluate the participation of Bhh pathway in neural crest development, we carried out gain- and loss-of-function approaches by directed microinjection of Bhh mRNA, its dominant-negative and morpholino oligonucleotides. Results showed that the overexpression of Bhh leads to an increased expression of neural crest markers and Gli transcription factors. On the other hand, the dominant-negative construct of Bhh and the morpholino oligonucleotide reduced the expression of neural crest markers, indicating Bhh signaling is required for neural crest specification. Additionally, the overexpression of Gli3 produced an expansion in neural crest territory mimicking the effect produced by Bhh gain of function. Our results show that Bhh signaling and Gli transcription factors are participating in the early neural crest development