The structure of a glycosylated protein hormone responsible for sex determination in the isopod, Armadillidium vulgare.
Two glycoforms (AH1 and AH2) of androgenic hormone, and its corresponding hormone precursor derived from HPLC-purified androgenic gland extract from the woodlouse Armadillidium vulgare were fully characterized by microsequencing and mass spectrometry. The amino-acid sequences of the two glycoforms were identical; they consist of two peptide chains, A and B, of 29 and 44 amino acids, respectively, with chain A carrying one N-glycosylated moiety on Asn18. The two chains are linked by two disulfide bridges. Glycoforms were only differentiated by the size and heterogeneity of the glycan chain. The androgenic hormone precursor (16.5 kDa) was shown to contain the sequence of chains A and B from the androgenic hormone, connected by a C-peptide (50 amino acids). These results were confirmed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) analysis performed on a single hypertrophied androgenic gland. When injected into young females, both glycoforms of the androgenic hormone were able to override genetic sex-determination. In invertebrates, there is no other example where sex-differentiation is controlled by a protein hormone that is not synthesized by the gonads but by a special gland. A functional comparison with two other hormones which are believed to play a role in sex determination, i.e. ecdysone in insects and anti-Müllerian hormone in mammals, is presented. Work is in progress to clone and characterize the gene encoding androgenic hormone, moreover special attention is devoted to its regulatory regions, putative targets for the Wolbachia action.
Laboratoire de Biologie Animale associé au CNRS, Poitiers, France. Gilbert.Martin@campus.univ-poitiers.fr
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Van Dorsselaer
D000595:Amino Acid Sequence; D000818:Animals; D002236:Carbohydrate Conformation; D002851:Chromatography, High Pressure Liquid; D003445:Crustacea / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D019281:Dimerization; D006023:Glycoproteins / Q000737:chemistry* / Q000302:isolation & purification / Q000502:physiology; D042341:Gonadal Hormones; D012739:Gonadal Steroid Hormones / Q000737:chemistry* / Q000302:isolation & purification / Q000502:physiology; D008297:Male; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry; D019849:Sex Determination Processes; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013440:Sulfides
D006023:Glycoproteins; D042341:Gonadal Hormones; D012739:Gonadal Steroid Hormones; D010446:Peptide Fragments; D011134:Polysaccharides; D013440:Sulfides; C053644:androgenic gland hormone (Armadillidium)