New insights into evolution of crustacean hyperglycaemic hormone in decapods--first characterization in Anomura.
The neuropeptides of the crustacean hyperglycaemic hormone (CHH) family are encoded by a multigene family and are involved in a wide spectrum of essential functions. In order to characterize CHH family peptides in one of the last groups of decapods not yet investigated, CHH was studied in two anomurans: the hermit crab Pagurus bernhardus and the squat lobster Galathea strigosa. Using RT-PCR and 3' and 5' RACE methods, a preproCHH cDNA was cloned from the major neuroendocrine organs (X-organs) of these two species. Hormone precursors deduced from these cDNAs in P. bernhardus and G. strigosa are composed of signal peptides of 29 and 31 amino acids, respectively, and CHH precursor-related peptides (CPRPs) of 50 and 40 amino acids, respectively, followed by a mature hormone of 72 amino acids. The presence of these predicted CHHs and their related CPRPs was confirmed by performing MALDI-TOF mass spectrometry on sinus glands, the main neurohaemal organs of decapods. These analyses also suggest the presence, in sinus glands of both species, of a peptide related to the moult-inhibiting hormone (MIH), another member of the CHH family. Accordingly, immunostaining of the X-organ/sinus gland complex of P. bernhardus with heterologous anti-CHH and anti-MIH sera showed the presence of distinct cells producing CHH and MIH-like proteins. A phylogenetic analysis of CHHs, including anomuran sequences, based on maximum-likelihood methods, was performed. The phylogenetic position of this taxon, as a sister group to Brachyura, is in agreement with previously reported results, and confirms the utility of CHH as a molecular model for understanding inter-taxa relationships. Finally, the paraphyly of penaeid CHHs and the structural diversity of CPRPs are discussed.
Montagné
Nicolas
N
Université Pierre et Marie Curie-Paris 6, FRE 2852 CNRS-Protéines: Biochimie Structurale et Fonctionnelle, Equipe Biogenèse des Peptides Isomères, Paris, France. nicolas.montagne@snv.jussieu.fr
Soyez
Daniel
D
Gallois
Dominique
D
Ollivaux
Céline
C
Toullec
Jean-Yves
JY
D000595:Amino Acid Sequence; D000818:Animals; D033381:Anomura / Q000235:genetics / Q000378:metabolism*; D060829:Arthropod Proteins; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D019143:Evolution, Molecular; D007447:Invertebrate Hormones; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D008121:Nephropidae / Q000235:genetics / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000145:classification* / Q000235:genetics*; D010802:Phylogeny; D011498:Protein Precursors / Q000235:genetics
D060829:Arthropod Proteins; D018076:DNA, Complementary; D007447:Invertebrate Hormones; D009419:Nerve Tissue Proteins; D011498:Protein Precursors; C015947:hyperglycemic hormone, crustacean; C061766:hyperglycemic hormone precursor, crustacean