Komodo-Warane sollen Giftdrüsen besitzen

[Daniel Hofer]

Wie ich gerade gelesen habe:

http://www.20min.ch/news/wissen/story/31183864

sollen Komodo-Warane über echte Giftdrüsen verfügen. Da stellt sich
die Frage, ob andere Waran-Arten auch über solche Gifte verfügen.
Was meinen die Waran-Spezialisten?

[Kidan]

Hallo,

Ja. Mittlerweile aber schon eine ganze Weile bekannt.

http://www.dghtserver.de/foren/showthread.php?t=74954

Husband (Draco - Ausgabe "Warane") berichtete schon vor etlichen Jahren, dass Bisse von V. primordius, fuer eine so kleine Echse recht schmerzhaft sind.

Beste Gruesse

[banyuls]

.....schmerzhafte Bisse müssen nicht gleich giftig sein! Gibt es da in der Draco nähere Infos?

Beste Grüße


Volker

[Kidan]

Hallo,

Nein, in der Draco nicht.


Husband, erwähnt die schwerzhaften Bisse von V. primordius, lediglich mit der sinngemäßen Anmerkung, "Was die Frage nach den Inhaltstoffen des Speichels aufwirft", was aber vor Fry war.
Mittlerweile hat Fry ja nachgewießen, dass alle Warane Giftdrüsen besitzen.


Alle weiteren Infos finden sich im anderen Thread.

Beste Grüße

[Ciliatus]

Mittlerweile hat Fry ja nachgewießen, dass alle Warane Giftdrüsen besitzen.

Hast du dazu ein Paper? Bzw eine Referenz?

lg

Ingo

[Kidan]

Hallo,

Das oft erwähnte Fry Paper:

Early evolution of the venom system in lizards and snakes (Fry et al. 2005)


Among extant reptiles only two lineages are known to have evolved venom delivery systems, the advanced snakes and helodermatid lizards (Gila Monster and Beaded Lizard)1. Evolution of the venom system is thought to underlie the impressive radiation of the advanced snakes (2,500 of 3,000 snake species)2, 3, 4, 5. In contrast, the lizard venom system is thought to be restricted to just two species and to have evolved independently from the snake venom system1. Here we report the presence of venom toxins in two additional lizard lineages (Monitor Lizards and Iguania) and show that all lineages possessing toxin-secreting oral glands form a clade, demonstrating a single early origin of the venom system in lizards and snakes. Construction of gland complementary-DNA libraries and phylogenetic analysis of transcripts revealed that nine toxin types are shared between lizards and snakes. Toxinological analyses of venom components from the Lace Monitor Varanus varius showed potent effects on blood pressure and clotting ability, bioactivities associated with a rapid loss of consciousness and extensive bleeding in prey. The iguanian lizard Pogona barbata retains characteristics of the ancestral venom system, namely serial, lobular non-compound venom-secreting glands on both the upper and lower jaws, whereas the advanced snakes and anguimorph lizards (including Monitor Lizards, Gila Monster and Beaded Lizard) have more derived venom systems characterized by the loss of the mandibular (lower) or maxillary (upper) glands. Demonstration that the snakes, iguanians and anguimorphs form a single clade provides overwhelming support for a single, early origin of the venom system in lizards and snakes. These results provide new insights into the evolution of the venom system in squamate reptiles and open new avenues for biomedical research and drug design using hitherto unexplored venom proteins.


Beste Grüße