Evolution of the cephalic glands in coral snakes: a comparative study within the family Elapidae

• Grant number: 18/09301-7
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Effective date (Start): August 26, 2018
• Effective date (End): August 25, 2019
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Inácio de Loiola Meirelles Junqueira de Azevedo
• Grantee: Leonardo de Oliveira
• Supervisor: Mark Wilkinson
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Research place: Natural History Museum, London, England

Abstract

Elapids are a group of venomous snakes for which the morphology of the cephalic glands is littleknown. The few studies involving these snakes focus on the morphology of venom glands, which arethe most studied cephalic glands among vertebrates. However, preliminary results have shown thatmicrurine snakes have an inferior rictal gland, a virtually unknown gland in elapids composedexclusively of serous cells. Furthermore, analysis of the transcripts of the rictal glands has shown theexpression of genes so far recognized only in the venom glands, revealing a broad and unexpectedcondition associated with the venom function in snakes. Such condition may have evolved in differentand non-homologous cephalic glands, such as the labial and rictal glands. This project aims toinvestigate the anatomy of the main cephalic glands (venom, accessory, infra- and supralabial,Harderian, nasal, and rictal glands) and their associated structures in the snakes of the family Elapidae,but with a major focus on the coral snakes (the less studied group of elapids in this respect). The workwill be performed at the Natural History Museum, a center of excellence in the study of biodiversitythat houses an unparalleled collection of snakes and the infrastructure needed to carry out the project.Because the study will use museum specimens (and some of them are rare), glandular morphology willbe characterized using mainly diffusible iodine-based contrast-enhanced computed tomography, a lessinvasive and non-destructive method that enables the integrated visualization of micro- andmacrostructures of non-mineralized tissues. The generated morphological data will be analyzedcomparatively using phylogenetic comparative methods and the most current phylogenetichypotheses to reconstruct the evolution of the glandular apparatus within elapids, as well as toformulate hypotheses about the function of these glands in coral snakes.