Immunological relationships between neuropeptides from the sinus gland of the lobster Homarus americanus, with special references to the vitellogenesis inhibiting hormone and crustacean hyperglycemic hormone.

Antisera raised in guinea pigs against four major neuropeptides purified from sinus glands of the lobster, Homarus americanus, were used to study the immunological relationships between several sinus gland peptides. On the basis of their behavior in ELISA and in absorption procedures, three groups of peptides are defined. Two groups may be related to the crustacean hyperglycemic hormone (CHH groups); the third one is composed of three immunologically identical peptides and, since one of these peptides was characterized in previous studies as a vitellogenesis inhibitor, is referred to as VIH group. This closely meets our present knowledge about the physiological effects and biochemical characteristics of these neuropeptides and gives immunological insights on the question of molecular polymorphism of lobster neurohormones.

Immunochemical and immunocytochemical studies of the crustacean vitellogenesis-inhibiting hormone (VIH).

Immunochemical investigations, using dot immunobinding assay (DIA) and enzyme-linked immunosorbent assay (ELISA), and immunocytochemical studies reveal the following new information about crustacean vitellogenesis-inhibiting hormone (VIH): (1) The structure of VIH is sufficiently different from that of the other sinus gland neuropeptides to allow a selective recognition of VIH by polyclonal antibodies. (2) From immunochemical criteria, VIH does not seem strictly species specific. The antisera raised against VIH of Homarus americanus cross-react with sinus gland extracts of Palaemonetes varians, Palaemon serratus, Macrobrachium rosenbergii, Carcinus maenas, and Porcellio dilatatus. (3) In the sinus gland of H. americanus, VIH immunoreactivity is localized mainly in electron-dense granules of medium size (110-185 nm in diameter) while, in P. dilatatus, the labeling is mostly on the largest granules (200-270 nm in diameter).

Subcellular localization of vitellogenin in crustacean adipocytes by the unlabelled antibody enzyme method.

The subepidermal fat body of the Amphipod Crustacean Orchestia gammarellus shows ultrastructural modifications related to vitellogenin synthesis. In the adipocytes of vitellogenic females, the rough endoplasmic reticulum is well developed whereas in those of males and non-vitellogenic females it is almost entirely absent; lipids and glycogen are, on the contrary, less abundant. The unlabelled antibody enzyme method shows the presence of vitellogenin in the dense bodies of the adipocytes of vitellogenic females. Adipocytes of males and non-vitellogenic females are not immunoreactive.

[Hormonal control of vitellogenin synthesis in the Amphipoda Crustacea Orchestia gammarella (Pallas)]. / Quelques aspects du contrôle hormonal de la synthèse de la vitellogénine chez le crustacé amphipode Orchestia gammarella (Pallas).

The presence of a vitellogenin stimulating ovarian hormone (VSOH) in Orchestia gammarella has been demonstrated by gonadectomy and ovary grafting. Vitellogenin synthesis is not affected by molting hormone injection; it decreases after Y-organ (molting gland) cauterization. Studies in progress seem to indicate that the destruction of the median area of the protocerebrum is followed by a decrease of this synthesis.

[Determination of the molecular weight of vitellogenin and of lipovitellins of Orchestia gammarella, Crustacea, Amphipoda]. / Détermination du poids moléculaire de la vitellogénine et des lipovitellines d'Orchestia gammarella, Crustacé Amphipode.

Vitellogenin and lipovitellins of Orchestia gammarella, tested by electrophoresis on gels of different acrylamide concentrations, following the procedure of Hedrick and Smith (1968), displays a migration pattern identical to that of proteins of respectively congruent to 4 x 10(5) (vitellogenin), congruent to 3,5 x 10(5) (lipovitellins I and I') and congruent to 5 x 10(5) (lipovitellin II) molecular weights.

6,10,14-Trimethylpentadecan-2-one and 6,10,14-trimethyl-5-trans, 9-trans, 13-pentadecatrien-2-one from the androgenic glands of the male crab Carcinus maenas.

2 C18 isoprenoid ketones, hexahydrofarnesylacetone (1) and farnesylacetone (2) have been identified for the first time in lipid extracts from the androgenic glands of the male crab Carcinus maenas, using coupled gas chromatography-mass spectrometry. The 2 compounds prepared by synthesis, are biologically active, inhibiting the incorporation of 3H-leucine in Crustaceans ovaries subcultures.

[Biological methylations in the crab Carcinus maenas; in vitro inhibition by a fraction purified from androgen gland extracts]. / Méthylations biologiques chez le crabe Carcinus maenas; inhibition in vitro par une fraction purifiée extraite des glandes androgènes

Extracts from muscles, testis, seminal vesicles and ovaries of the Crab, Carcinus maenas, have been studied in vitro, in presence of [14C]-methyl S-adenosylmethionine, with an E. coli tRNA as methyl acceptor. The highest level of methylases is found in the testis. It has been reported previously that a purified fraction extracted from the androgenic glands of Carcinus maenas inhibits the vitellogenesis in ovaries. We now show that the same fraction inhibits tRNA methylation in an extract of testis as methylase; a 50% inhibition is obtained with about 10 mug of a purified fraction corresponding to 15 glands. With an enzymatic preparation from the ovaries, a 50% inhibition of the tRNA methylase is observed with the purified extract from 4 glands.