Abstract
Synopsis. This paper summarizes our recent work on the histological, physiolog? ical and molecular aspects of limb regeneration in the fiddler crab Uca pugilator and new information is presented on mitotic activity in the blastema during the first days of blastemal organization. We also report for the first time the locali? zation of vertebrate growth factor immunoreactivity (FGF 2 and FGF 4) in the regenerating blastema. In the first part of this paper we review recent histological findings concerning the physical events that accompany autotomy of limbs and propose a new function for the autotomy membrane?the tethering of the regen? erating pedal nerve to the walls of the coxa. In the second part of the paper we review our recent findings on the identification and characterization of the Uca ecdysteroid receptor (UpEcR, and its potential dimer partner, the retinoid-X-receptor, UpRXR). Using (/ca-specific antibody probes raised in our lab, we have been able to identify specific cells in the early blastema that express receptor pro? teins. The regenerating limb of the fiddler crab is responsive to both steroids and retinoids and mRNA for steroid and retinoid receptors are expressed in the re? generating limb buds during all stages of regeneration. The DNA and deduced amino acid sequences of the ecdysteroid receptor is very similar to the sequences of insect EcRs, while the retinoid receptor is similar to insect protein (ultraspiracle) in the DNA-binding domain, but closer to vertebrate RXRs in the ligand binding domain.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.