Embryonic development of the venom-delivery system in snakes: a morphological and molecular approach with emphasis on its secondary loss or reduction

• Grant number: 14/14364-7
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2014
• End date: November 30, 2017
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Hussam El Dine Zaher
• Grantee: Leonardo de Oliveira
• Host Institution: Museu de Zoologia (MZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 11/50206-9 - Origin and evolution of snakes and their diversification in the Neotropics: a multidisciplinary approach, AP.BTA.TEM

Abstract

Only some groups of advanced snakes (Caenophidia) possess a venom delivery system (VDS) constituted by venom or Duvernoy glands associated with specialized dentition and musculature for venom inoculation. The acquisition of a "venomous" apparatus is thought to have triggered the successful radiation of Caenophidia, while its reduced condition or absence is interpreted as the result of secondary loss. Recent studies proposed a new model for the evolution of the VDS structures, in which the embryonic maxillary lamina is divided into anterior and posterior laminae that originate the anterior maxillary teeth and the fangs and associated venom or Duvernoy's glands, respectively. However, there is virtually no knowledge about the mechanisms associated with secondary losses of these structures. This project aims to identify the processes associated with the embryonic development of the VDS in snakes and, especially, its secondary loss or reduction. Additionally, the project intends to test the new model of embryonic development suggested in the more recent literature. Both morphological and molecular aspects of embryonic development of the VDS will be analyzed respectively through the anatomical, histological and immunohistochemical study and through the genetic expression of genes linked to the different stages of embryonic development of the VDS components in the following species: Viperidae (Bothrops jararaca), Elapidae (Micrurus corallinus), Colubridae (Pantherophis guttatus) and Dipsadidae (Sibynomorphus mikanii and Oxyrhopus guibei). (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DE OLIVEIRA, LEONARDO; GUERRA-FUENTES, RICARDO ARTURO; ZAHER, HUSSAM. Embryological evidence of a new type of seromucous labial gland in neotropical snail-eating snakes of the genus Sibynornorphus. ZOOLOGISCHER ANZEIGER, v. 266, p. 89-94, 2017. (14/14364-7, 11/50206-9)

DE OLIVEIRA, LEONARDO; SCARTOZZONI, RODRIGO ROVERI; DE ALMEIDA-SANTOS, SELMA MARIA; JARED, CARLOS; ANTONIAZZI, MARTA MARIA; SALOMAO, MARIA DA GRACA. Morphology of Duvernoy's Glands and Maxillary Teeth and a Possible Function of the Duvernoy's Gland Secretion in Helicops modestus Gunther, 1861 (Serpentes: Xenodontinae). South American Journal of Herpetology, v. 11, n. 1, p. 54-65, APR 2016. (14/14364-7)