title: Expression of the genes encoding the ecdysteroid and retinoid receptors in regenerating limb tissues from the fiddler crab, Uca pugilator.
abstract: Using sequence information derived from the Drosophila melanogaster (Dm) ecdysteroid receptor (EcR)- and retinoid X receptor (RXR)-encoding gene homologs, we have isolated cDNA clones corresponding to the DNA-binding domains (DBD) for these two nuclear receptors from the fiddler crab, Uca pugilator (Up). Both genes appear to be represented in 1-2 copies in the Up genome, and unlike Dm, contain an intron within the DBD-encoding region. Sequence comparisons to the Dm EcR and RXR homologs indicate 76 and 82% nucleotide identity, respectively, corresponding to 6 and 4 single-amino acid substitutions which primarily cluster in the region of the molecule involved in dimerization. RT-PCR analysis indicates that both the EcR and RXR homologs are expressed during the initial stages of limb regeneration, temporally concomitant with early blastema formation and the secretion of a flexible sac cuticle at the site of limb loss.
authors.affiliation: Department of Zoology, University of Oklahoma, Norman 73019, USA. ddurica@uoknor.edu
authors.forename: D S
authors.initials: DS
authors.lastname: Durica
authors.forename: P M
authors.initials: PM
authors.lastname: Hopkins
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D003386:Brachyura / Q000235:genetics* / Q000502:physiology; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D005121:Extremities / Q000502:physiology*; D008969:Molecular Sequence Data; D018168:Receptors, Retinoic Acid / Q000235:genetics* / Q000378:metabolism; D011987:Receptors, Steroid / Q000235:genetics* / Q000378:metabolism; D012038:Regeneration / Q000235:genetics*; D047488:Retinoid X Receptors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D018076:DNA, Complementary; D018168:Receptors, Retinoic Acid; D011987:Receptors, Steroid; D047488:Retinoid X Receptors; D014157:Transcription Factors; C034808:ecdysteroid receptor