Abstract
We have isolated the chicken homeobox genes LH-2A and LH-2B encoding two related LIM domain-containing homeodomain proteins and examined the expression pattern during chick limb development. LH-2A is most closely related to human and rat LH-2, while LH-2B is less conserved. Although both LH-2A and LH-2B are expressed in the limb mesenchyme throughout stage 16 to stage 32, LH-2A transcripts are detectable in the distal limb bud and LH-2B transcripts are detectable in the anterior limb bud. Signals from the apical ectodermal ridge positively regulate LH-2A expression, since removal of the apical ectoderm resulted in the rapid reduction of LH-2A expression in the distal limb mesenchyme. Ectopic expression of the sonic hedgehog gene in the anterior margin of the limb bud resulted in the rapid reduction of LH-2B expression accompanying respecification of the positional value to the posterior phenotype. These results suggest that LH-2A and LH-2B play important roles in the determination and specification of the proximal-distal and anterior-posterior positional values, respectively.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 506-511 |
| Number of pages | 6 |
| Journal | Biochemical and Biophysical Research Communications |
| Volume | 238 |
| Issue number | 2 |
| DOIs | |
| State | Published - Sep 18 1997 |
| Externally published | Yes |
Bibliographical note
Funding Information:We thank Rie Nakao and Chikako Komaguchi for their technical assistance. This work was supported in part by Grants-in-Aids from the Japanese Ministry of Education, Science and Culture, and by a Research Project Grant from Kawasaki Medical School.