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TWISTing a Hand on the mandible
Author(s) -
Ruest L. Bruno,
Zhang Yanping,
Blackwell Evan L.,
McKnight Mitchell T.,
Knutsen Gregory R.
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.334.4
Subject(s) - transcription factor , biology , neural crest , embryo , mutant , anatomy , mandible (arthropod mouthpart) , runx2 , gene , microbiology and biotechnology , genetics , botany , genus
Formation of the mandible requires the exquisite control of neural crest cell (NCC) development. Transcription factors controlling the early proximo‐distal development of the mandibular NCC are mostly elusive. We hypothesized that the interacting basic helix‐loop‐helix (bHLH) transcription factors are involved. One of these factors is the Saethre‐Chotzen gene Twist1 . To investigate the function of Twist1 during mandibular development, we conditionally inactivated the gene at E9.5 in the mandibular arch NCC using the Hand2‐Cre mouse line. The mandible in the Twist1 mutant embryos was shorter due to the reduction of the proximal articular elements. The expression of several markers of lower jaw development appeared to be normal, including the bHLH factors Hand1 and Hand2 . Unexpectedly, mandibular mineralization was affected in the heterozygous embryos, likely due to an imbalance between Twist1 and Hand2 to regulate Runx2 function. The expression of miR‐199 and 214 was normal in the mutant embryos and our results revealed that Hand2 is also controlling the expression of these microRNAs. These results suggest that Twist1 and Hand2 interact during mandibular development, but each factor may also have independent functions that depend on its own interactions with other factors or themselves. Further studies are needed to understand the role of the interaction between Twist1 and Hand2 in mandibular development.