The newly described homeobox gene Xgbx-2 is expressed during gastrulation and neurulation in the dorsolateral ectoderm. Gbx-2 becomes restricted to the neuroectoderm at the mid/hindbrain boundary and in the epidermis ventral and lateral to the neural plate. To assess function during early development we injected synthetic Xgbx-2 RNA into specific blastomeres at the 4 and 8 cell stage. Injection of Xgbx-2 (0.1 to 0.8 ng) into both dorsal blastomeres at the 4 cell stage results in a high incidence of gastrulation defects (open backs) and posthatchlings with reduced dorsal and anterior structures (eye size and cement gland size were reduced). The Xgbx-2 phenotype is dependent on the blastomeres that are injected. The two ventral blastomeres at the 4 cell stage and the two vegetal/ventral blastomeres at the 8 cell stage are the least affected. Surprisingly, the two dorsal blastomeres at the 4 cell stage are more sensitive to Xgbx-2 than either the two animal/dorsal or vegetal/dorsal blastomeres at the 8 cell stage. These results are consistent with the working hypothesis that the function of Xgbx-2 is inhibitory, affecting gastrulation and anterior/dorsal development, leading to the establishment of the mid/hindbrain boundary.
|Original language||English (US)|
|State||Published - Dec 1 1996|
ASJC Scopus subject areas
- Molecular Biology