We examined the effects of synthetic retinoids on the jaw development of Japanese flounder during postembryonic development. Flounder larvae were exposed to Am80 [a retinoic acid receptor (RAR)α/β-selective retinoid] and methoprene acid [MA, a retinoid X receptor (RXR)-selective retinoid]. Am80 induced lower jaw deformities in all fish, whereas MA induced lower jaw deformities in less than 20% of the fish. Am80 caused drastic deformities in the upper jaw as well as the lower jaw, while MA did not affect the upper jaw. RT-PCR analysis of the lower jaw revealed that RAR expression was greatly increased by Am80 treatment. Expression of patched (ptc) which is a receptor of the hedgehog family, was inhibited by both Am80 and MA treatments. Immunohistochemistry using anti-RARα-antibody revealed that RARα-positive osteoblasts exist around the jaw bones. We propose that disturbance of the RAR signaling pathway regulating osteoblast activity is mainly responsible for the jaw deformities.
|Number of pages||12|
|Publication status||Published - 2003 May 1|
- Japanese flounder
ASJC Scopus subject areas
- Aquatic Science