| First Author | Helmbacher F | Year | 1998 |
| Journal | Development | Volume | 125 |
| Issue | 23 | Pages | 4739-48 |
| PubMed ID | 9806922 | Mgi Jnum | J:50514 |
| Mgi Id | MGI:1306866 | Doi | 10.1242/dev.125.23.4739 |
| Citation | Helmbacher F, et al. (1998) Hoxa1 and Krox-20 synergize to control the development of rhombomere 3. Development 125(23):4739-48 |
| abstractText | The transcription factor genes Hoxa1 and Krox-20 have been shown to play important roles in vertebrate hindbrain segmentation. In this report, we present evidence for novel functions of these genes which co-operate in specifying cellular identity in rhombomere (r) 3. Although Hoxa1 has not been observed to be expressed rostrally to the prospective r3/r4 boundary, its inactivation results in (i) the appearance of patches of cells presenting an r2-like molecular identity within r3, (ii) early neuronal differentiation in r3, normally characteristic of even-numbered rhombomeres, and (iii) abnormal navigation of r3 motor axons, similar to that observed in even-numbered rhombomeres. These phenotypic manifestations become more severe in the context of the additional inactivation of one allele of the Krox-20 gene, demonstrating that Hoxa1 and Krox-20 synergize in a dosage-dependent manner to specify r3 identity and odd- versus even-numbered rhombomere characters. In addition, these data suggest that the control of the development of r3 may not be autonomous but dependent on interactions with Hoxa1-expressing cells. |
