[en] 1. Objective
The twist1a and twist1b genes code for transcription factors involved during embryogenesis in the craniofacial development. The human ortholog of twist1a and twist1b, TWIST1 has been shown to be mutated in cases of the Saethre–Chotzen syndrome (SCS). However, the roles of these genes in skeletal development in zebrafish remain to be clarified. The aim of our research is to characterize the effects of the knock-down of twist1a and twist1b in the zebrafish.
2. Methods
Antisens morpholino are used for the knock-down of twist1a and twist1b (respectively MoTwist1a and MoTwist1b). The sox9a expression is investigated using whole amount in situ hybridization.
3. Results
We show the spatio-temporal expression pattern of twist1a and twist1b during the first 6 days of zebrafish development and present the effects observed on cartilage and bone formation upon knock-down of these genes in zebrafish larvae. The results reveal a decrease of the cranial cartilage and bone formation in both MoTwist1a and MoTwist1b. Interestingly, when MoTwist1a and MoTwist1b are co-injected, the cranial cartilage formation is strongly reduced, while ectopic cartilage formation appeared in the front of the head. We also show an increase in expression of sox9a, a master regulator of chondrogenesis, in morphants.
4. Summary and Conclusions
Even though it was shown that twist1a and twist1b maintain a pool of osteoprogenitor-like cells, we show that a knock-down of these genes induces a decrease of skeletal formation. Our hypothesis is that the morphants run out of progenitor cells to assure correct bone and cartilage formation. In the future, we plan to generate twist1a mutants in order to further characterize the effect of this mutation. The twist1a mutant will eventually serve for a rescue study using human TWIST1 mRNA, wild-type or mutant in order to have a better understanding of the human disorder SCS.
Research Center/Unit :
GIGA‐R - Giga‐Research - ULiège
Disciplines :
Biochemistry, biophysics & molecular biology
Author, co-author :
Zappia, Jérémie ; Université de Liège > Département des sciences de la vie > GIGA-R : Biologie et génétique moléculaire
Other collaborator :
Windhausen, Thomas ; Université de Liège - ULiège > Doct. sc. (bioch., biol. mol.&cell., bioinf.&mod.-Bologne)
Renn, Jörg ; Université de Liège > Département des sciences de la vie > GIGA-R : Biologie et génétique moléculaire
Muller, Marc ; Université de Liège > Département des sciences de la vie > GIGA-R : Biologie et génétique moléculaire
Language :
English
Title :
Basic Helix loop Helix transcription factor twist1a and twist1b and their involvement in the skeletal development of zebrafish.
Publication date :
May 2017
Event name :
ECTS2017 44th European Calcified Tissue Society Congress
Event place :
Salzburg, Austria
Event date :
12 mai 2017 au 16 mai 2017
By request :
Yes
Audience :
International
Name of the research project :
Basic Helix loop Helix transcription factor twist1a and twist1b and their involvement in the skeletal development of zebrafish