RESUMEN
A cDNA encoding the complete precursor of the putative molt-inhibiting hormone (MIH) of the shore crab, Carcinus maenas, was isolated and sequenced. The precursor consists of a putative 35 amino acid signal peptide and the 78 amino acid mature MIH. The deduced MIH amino acid sequence is in complete agreement with the sequence previously determined by Edman degradation. In situ hybridization revealed MIH-expression in a subpopulation of large neurosecretory perikarya of the medulla terminalis X-organ in the eyestalk.
Asunto(s)
Hormonas de Invertebrados/genética , Precursores de Proteínas/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Braquiuros , Clonación Molecular , ADN , Hormonas de Invertebrados/química , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Precursores de Proteínas/químicaRESUMEN
The pigment-dispersing hormone (PDH) is produced in the eyestalks of Crustacea where it induces light-adapting movements of pigment in the compound eye and regulates the pigment dispersion in the chromatophores. To study this hormone at the mRNA level, we cloned and sequenced cDNA encoding PDH in the crayfish Orconectes limosus. The structure of the PDH preprohormone consists of a signal peptide, a PDH precursor-related peptide (PPRP) and the highly conserved PDH peptide at the carboxy-terminal end. In situ hybridization in combination with immunocytochemistry revealed four cell clusters expressing PDH in the optic ganglia of the eyestalk. Three clusters stained both with the PDH cRNA probe and the PDH antiserum, however, the perikarya in the lamina ganglionaris (LG) only stained with the PDH antiserum, suggesting the presence of a PDH-like peptide in the LG.
Asunto(s)
Astacoidea/fisiología , Péptidos/genética , ARN Mensajero/genética , Secuencia de Aminoácidos , Animales , Astacoidea/genética , Secuencia de Bases , Clonación Molecular , Ojo/citología , Biblioteca de Genes , Inmunohistoquímica , Hibridación in Situ , Hormonas de Invertebrados/genética , Datos de Secuencia Molecular , Fibras Nerviosas/fisiología , Fibras Nerviosas/ultraestructura , Fenómenos Fisiológicos Oculares , Oligodesoxirribonucleótidos , Sondas ARN , ARN Mensajero/análisis , Homología de Secuencia de AminoácidoRESUMEN
A cDNA encoding the precursor of the red pigment concentrating hormone (RPCH) of the shore crab, Carcinus maenas, was isolated and sequenced. The predicted preprohormone sequence consists of a putative 25 amino acid signal peptide, the eight amino acid RPCH sequence followed by a Gly as amide donor, a dibasic processing site and a 74 residue peptide of unknown function, referred to as RPCH-precursor-related peptide (RPRP). In in situ hybridisation experiments, the RPCH gene transcript could be localised in two clusters of neurons in the medulla terminalis of the eyestalk.
Asunto(s)
Braquiuros/metabolismo , Hormonas de Invertebrados/biosíntesis , Oligopéptidos/biosíntesis , Precursores de Proteínas/biosíntesis , ARN Mensajero/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Biblioteca de Genes , Hibridación in Situ , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos , Oligonucleótidos Antisentido , Oligopéptidos/genética , Reacción en Cadena de la Polimerasa/métodos , Precursores de Proteínas/genética , Ácido Pirrolidona Carboxílico/análogos & derivados , ARN Mensajero/análisis , ARN Mensajero/biosíntesisRESUMEN
The cDNA encoding the precursor of the pigment dispersing hormone (PDH) of the shore crab, Carcinus maenas, was isolated and sequenced. The precursor consists of a putative 22 amino acid signal peptide, a putative 33 residue peptide of unknown function, and the 18 amino acid mature PDH, followed by a Gly residue which serves as a possible amide donor. The deduced mature PDH amino acid sequence is identical to those of Uca pugilator and Cancer magister, previously determined by Edman degradation.