Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
XB-ART-9472
Mech Dev March 1, 2001; 101 (1-2): 91-103.

Increased XRALDH2 activity has a posteriorizing effect on the central nervous system of Xenopus embryos.



Abstract
Retinoic acid (RA) metabolizing enzymes play important roles in RA signaling during vertebrate embryogenesis. We have previously reported on a RA degrading enzyme, XCYP26, which appears to be critical for the anteroposterior patterning of the central nervous system (EMBO J. 17 (1998) 7361). Here, we report on the sequence, expression and function of its counterpart, XRALDH2, a RA generating enzyme in Xenopus. During gastrulation and neurulation, XRALDH2 and XCYP26 show non-overlapping, complementary expression domains. Upon misexpression, XRALDH2 is found to reduce the forebrain territory and to posteriorize the molecular identity of midbrain and individual hindbrain rhombomeres in Xenopus embryos. Furthermore, ectopic XRALDH2, in combination with its substrate, all-trans-retinal (ATR), can mimic the RA phenotype to result in microcephalic embryos. Taken together, our data support the notion that XRALDH2 plays an important role in RA homeostasis by the creation of a critical RA concentration gradient along the anteroposterior axis of early embryos, which is essential for proper patterning of the central nervous system in Xenopus.

PubMed ID: 11231062
Article link: Mech Dev

Genes referenced: aldh1a2 atr cyp26a1 egr2 en2 gal.2 h4c4 hoxb9 otx2 pc.1


Article Images: [+] show captions


Xenbase: The Xenopus laevis and X. tropicalis resource.
Version: 4.12.0


Major funding for Xenbase is provided by grant P41 HD064556