| First Author | Maconochie M | Year | 1999 |
| Journal | Development | Volume | 126 |
| Issue | 7 | Pages | 1483-94 |
| PubMed ID | 10068641 | Mgi Jnum | J:54843 |
| Mgi Id | MGI:1336374 | Doi | 10.1242/dev.126.7.1483 |
| Citation | Maconochie M, et al. (1999) Regulation of Hoxa2 in cranial neural crest cells involves members of the AP-2 family. Development 126(7):1483-94 |
| abstractText | Hoxa2 is expressed in cranial neural crest cells that migrate into the second branchial arch and is essential for proper patterning of neural-crest-derived structures in this region, We have used transgenic analysis to begin to address the regulatory mechanisms which underlie neural- crest-specific expression of Hoxa2, By performing a deletion analysis on an enhancer from the Hoxa2 gene that is capable of mediating expression in neural crest cells in a manner similar to the endogenous gene, we demonstrated that multiple cis-acting elements are required for neural-crest-specific activity. One of these elements consists of a sequence that binds to the three transcription factor AP-2 family members. Mutation or deletion of this site in the Hoxa2 enhancer abrogates reporter expression in cranial neural crest cells but not in the hindbrain, In both cell culture co-transfection assays and transgenic embryos AP-2 family members are able to trans-activate reporter expression, showing that this enhancer functions as an AP-2-responsive element in vivo, Reporter expression is not abolished in an AP-2 alpha null mutant embryos, suggesting redundancy with other AP-2 family members for activation of the Hoxa2 enhancer. Other cis-elements identified in this study critical for neural- crest-specific expression include an element that influences levels of expression and a conserved sequence, which when multimerized directs expression in a broad subset of neural crest cells. These elements work together to co-ordinate and restrict neural crest expression to the second branchial arch and more posterior regions, Our findings have identified the cis-components that allow Hoxa2 to be regulated independently in rhombomeres and cranial neural crest cells. |
