W chromosome in the Indian water snake (checkered keel back)Natrix piscator (colubridae)

Zusammenfassung Die diploide Chromosomenzahl beider Geschlechter beträgt 40: 10 Macrochromosomen und 30 Microchromosomen. Die GeschlechtschromosomenZZ () undZW () sind cytologisch erkennbar.     

Long term retention of colloidal thorium dioxide in the liver and spleen ofXenopus laevis daudin

Résumé Des observations ultrastructurales ont montré que le thorium bioxyde colloïdal (ThO₂) s'accumule dans le foie et la rate des grenouilles,Xenopus laevis, jusqu'à 3 ans après une seule injection de 10 mg pratiquée sur le jeune animal, 6 mois après sa métamorphose.     

The importance of the lateral line system for the perception of surface waves in the claw toad,Xenopus laevis daudin

Zusammenfassung Blinde Krallenfrösche reagieren auch dann auf konzentrische Oberflächenwellen, wenn das gesamte Seitenliniensystem zerstört wird. Weitere Ausschaltversuche zeigen, dass der Reiz (Eintauchen eines Stabes) sehr wahrscheinlich über das Labyrinth perzipiert wird. Ob die Oberflächenwelle selbst oder (und) das Geräusch beim Eintauchen des Stabes wahrgenommen wird, ist noch nicht sicher entschieden.

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My thanks are due to Dr.M. L. Mittelstaedt for critical help and to MissA. Middelmann for valuable technical assistance. This work was partly supported by a grant from the DFG.     

Protein complexes in snake venom

Snake venom contains mixture of bioactive proteins and polypeptides. Most of these proteins and polypeptides exist as monomers, but some of them form complexes in the venom. These complexes exhibit much higher levels of pharmacological activity compared to individual components and play an important role in pathophysiological effects during envenomation. They are formed through covalent and/or non-covalent interactions. The subunits of the complexes are either identical (homodimers) or dissimilar (heterodimers; in some cases subunits belong to different families of proteins). The formation of complexes, at times, eliminates the non-specific binding and enhances the binding to the target molecule. On several occasions, it also leads to recognition of new targets as protein-protein interaction in complexes exposes the critical amino acid residues buried in the monomers. Here, we describe the structure and function of various protein complexes of snake venoms and their role in snake venom toxicity.     

Fibrinolytic proteases in snake venoms

Zusammenfassung Fibrinolysine zweier Schlangengifte haben — im Gegensatz zu Plasmin und Trypsin — keinen Plasminogen-aktivierenden Effekt, noch sind sie durch Proteasen-Inhibitoren gehemmt. Sowohl in vivo wie auch in vitro sind sie durch Plasmaproteine inaktiviert, was jedoch nicht auf ₁ und ₂-Antiplasmine zurückzuführen ist. Die Spaltprodukte der Toxin-Fibrinogenolyse besitzen einen hohen Gehalt an Antithrombin VI.     

Myotoxic phospholipases A from snake venom,Pseudechis colletti,producing myoglobinuria in mice

Summary 2 proteins producing myoglobinuria in mice were isolated from the venom of the Australian elapid snakePseudechis colletti and identified as phospholipases A showing close similarities in amino acid composition to a similarly acting enzyme from a sea snake venom (Enhydrina schistosa).     

Naja siamensis, a cryptic species of venomous snake revealed by mtDNA sequencing

Because of possible variation in venom composition, an understanding of venomous snake systematics is of great importance for the optimization of antivenom treatment of snakebite patients. Intraspecific variation in the morphology of many venomous snakes complicates the definition and indentification of some species when allopatric populations are involved. Selectively neutral or near-neutral mtDNA sequences can reveal evolutionary relationships obscured by ecogenetically-caused morphological variation. We use comparative sequencing of the cytochrome oxidase subunit 1 gene to reveal the existence of a widespread, cryptic species of spiting cobra from southeast Asia. This species,Naja siamensis, is widely sympatric with other Asiatic cobra species. This may be of considerable medical significance, and calls for further research into venom composition in Asiatic cobras.     

The largest known chromosome number for a mammal,in a South American desert rodent

Summary Tympanoctomys barrerae, a desert specialist member of the family Octodontidae, until now thought to be conservative, and ancestral to South American hystricognath rodents, presents the highest diploid chromosome number (2n=102) known in a mammal. Unexpectedly, its karyotype was found to be composed mainly of metacentric to sub-metacentric chromosomes. Mechanisms by which such a karyotype may have been derived are discussed.     

Aplysianin-A,an antibacterial and antineoplastic glycoprotein in the albumen gland of a sea hare,Aplysia kurodai

Summary Aplysianin-A, an antibacterial and antineoplastic factor in the albumen gland of the sea hareAplysia kurodai, was isolated. It had a molecular weight of approximately 320 kD and consisted of subunits with a molecular weight of 85 kD. It contained 9.8% neutral sugar. Aplysianin A showed 50% inhibition ofBacillus subtilis growth at a concentration of 4 g protein/ml and 50% lysis of murine MM46 tumor cells at 14 ng protein/ml. A partial identity of antigenic specificity of the purified specimen with an antineoplastic factor fromAplysia eggs was observed in immunodiffusion tests.Acknowledgment. We are indebted to the staff of Fisheries Research Laboratory, Faculty of Agriculture, University of Tokyo, Maisaka, for the collection of sea hares.     

Aplysianin-A, an antibacterial and antineoplastic glycoprotein in the albumen gland of a sea hare, Aplysia kurodai

Aplysianin-A, an antibacterial and antineoplastic factor in the albumen gland of the sea hare Aplysia kurodai, was isolated. It had a molecular weight of approximately 320 kD and consisted of subunits with a molecular weight of 85 kD. It contained 9.8% neutral sugar. Aplysianin A showed 50% inhibition of Bacillus subtilis growth at a concentration of 4 microgram protein/ml and 50% lysis of murine MM46 tumor cells at 14 ng protein/ml. A partial identity of antigenic specificity of the purified specimen with an antineoplastic factor from Aplysia eggs was observed in immunodiffusion tests.     

Isolation and characterization of hallachrome,a red pigment from the sea wormHallaparthenopeia

Riassunto Viene descritto l'isolamento e la caratterizzazione dello Hallacromo, il pigmento epiteliale del verme marinoHalla parthenopeia che è stato oggeto di numerose ricerche fin dal 1931. Sulla base dei risultati ottenuti si può concludere che il pigmento, contrariamente a quanto riportato da altri Autori, è un metilmetossi-ossi-1, 2-antrachinone (I). Sono in corso ulteriori ricerche per giungere alla definizione completa della struttura del pigmento, che è il primo antrachinone rinvenuto in natura non sostituito nelle posizioni 9 e 10.

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This investigation was supported by a grant from Laboratorio per la Chimica e Fisica di Molecole di Interesse Biologico del C.N.R., Napoli.     

On the multiple sex chromosome mechanism in a lygaeid,Oxycarenus hyalinipennis (Costa)

Résumé Oxycarenus hyalinipennis (Costa) possède vraisemblablement des chromosomes sexuels multiples du typeX ₁ X ₂ Y. Les métaphases diploïdes renferment, soit 17, soit 19 éléments. Les 2 éléments supplémentaires des cinèses à 19, bien que comparables auxm-chromosomes des autres Lygéides, diffèrent de ces derniers en certains points de leur comportement qui évoque celui des «surnuméraires» trouvés chez d'autres insectes. La méiose est du type habituel chez les Hétéroptères.     

Ventilatory responses to CO2 at different body temperatures in the snake,Coluber constrictor

Summary Ventilatory responses to CO₂ were examined at different temperatures in the snake,Coluber constrictor. CO₂ sensitivity increased between 15 and 25°C but not between 25 and 35°C. A rapidly occurring off-CO₂ transient hyperpnea suggested the presence of an intrapulmonary chemoreceptor.     

Biometric analysis of incipient speciation in the ringed snake,Natrix natrix (L.)

Résumé On souligne l'importance d'un procédé convenable pour analyser la variation géographique. L'efficacité d'une méthode multivariante de la taxonomie numérique (l'analyse canonique) en réduisant une situation compliquée et hypermultivariable dans un modèle oligovariant intelligible est indiqué. On montre commentN. natrix donne l'exemple de la naissance d'espèces (influence de la calotte glaciaire) et de l'apport variable de gènes communs et on propose aussi de restreindre l'emploi de sous-espèces pour une espèce naissante.     

Antibacterial activity in the egg mass of a sea hare

Summary The eggs of a sea hare,Aplysia kurodai, contained antibacterial factors which probably play a role in the defense of eggs against bacterial infection. The active factors were composed of several heat-labile proteins, unrelated to lysozyme, and were produced in the albumen gland.     

12-hydroxy-E-gamma-bisabolene, a new sesquiterpene alcohol from a Caribbean sea whip of the genus Pseudopterogorgia (Gorgonacea, Cnidaria)

A new sesquiterpene alcohol, 12-hydroxy-E-gamma-bisabolene, is reported from an undescribed Caribbean sea whip of the genus Pseudopterogorgia. The structure of this new alcohol was established based upon spectral analyses and through chemical interconversions.     

Salivary chromosome-like structure of a coccid chromosome

Résumé Démonstration d'une structure analogue à celle des chromosomes géants des Diptères chez un Coccide.