Structural and Molecular Diversification of the Anguimorpha Lizard Mandibular Venom Gland System in the Arboreal Species Abronia graminea

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Koludarov, I (Author) Other; Sunagar, K (Author) Other; Undheim, EAB (Author) Other; Jackson, TNW (Author) Other; Ruder, T (Author) Other; Whitehead, D (Author) Other; Saucedo, AC (Author) Other; Roberto Mora, GR (Author) Other; Alagon, AC (Author) Other; King, G (Author) Other; Agostinho Antunes (Author) FCUP; Fry, BG (Author) Other

Journal

Title: Journal of Molecular Evolution

Vol. 75

Pages: 168-183

ISSN: 0022-2844

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 15 Citations

Scopus - 16 Citations

Other information

Authenticus ID: P-002-2T7

DOI: 10.1007/s00239-012-9529-9

Abstract (EN): In the past, toxinological research on reptiles has focused principally on clinically important species. As a result, our understanding of the evolution of the reptile venom system is limited. Here, for the first time, we describe the structural and molecular evolutionary features of the mandibular toxin-secreting gland of Abronia graminea, a representative of one of the poorly known and entirely arboreal lineages of anguimorph lizards. We show that the mandibular gland is robust and serous, characters consistent with those expected of a toxin-secreting gland in active use. A wide array of transcripts were recovered that were homologous to those encoded by the indisputably venomous helodermatid lizards. We show that some of these toxin transcripts are evolving under active selection and show evidence of rapid diversification. Helokinestatin peptides in particular are revealed to have accumulated residues that have undergone episodic diversifying selections. Conversely, the natriuretic peptides have evolved under tremendous evolutionary constraints despite being encoded in tandem with helokinestatins by the same gene precursor. Of particular note is the sequencing for the first time of kunitz peptides from a lizard toxin-secreting gland. Not only are kunitz peptides shown to be an ancestral toxicoferan toxin, the ancestral state of this peptide is revealed to be a dual domain encoding precursor. This research provides insight into the evolutionary history of the ancient toxicoferan reptile venom system. In addition, it shows that even 'clinically irrelevant' species can be a rich source of novel venom components, worthy of investigation for drug design and biomedical research.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 16