title: Insights into the Evolution of a Snake Venom Multi-Gene Family from the Genomic Organization of Echis ocellatus SVMP Genes.
abstract: The molecular events underlying the evolution of the Snake Venom Metalloproteinase (SVMP) family from an A Disintegrin And Metalloproteinase (ADAM) ancestor remain poorly understood. Comparative genomics may provide decisive information to reconstruct the evolutionary history of this multi-locus toxin family. Here, we report the genomic organization of Echis ocellatus genes encoding SVMPs from the PII and PI classes. Comparisons between them and between these genes and the genomic structures of Anolis carolinensis ADAM28 and E. ocellatus PIII-SVMP EOC00089 suggest that insertions and deletions of intronic regions played key roles along the evolutionary pathway that shaped the current diversity within the multi-locus SVMP gene family. In particular, our data suggest that emergence of EOC00028-like PI-SVMP from an ancestral PII(e/d)-type SVMP involved splicing site mutations that abolished both the 3' splice AG acceptor site of intron 12* and the 5' splice GT donor site of intron 13*, and resulted in the intronization of exon 13* and the consequent destruction of the structural integrity of the PII-SVMP characteristic disintegrin domain.
authors.affiliation: Laboratorio de Ven&#243;mica Estructural y Funcional, Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Cient&#237;ficas, Jaume Roig 11, 46010 Val&#232;ncia, Spain. libia.sanz@ibv.csic.es.
authors.forename: Libia
authors.initials: L
authors.lastname: Sanz
authors.affiliation: Laboratorio de Ven&#243;mica Estructural y Funcional, Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Cient&#237;ficas, Jaume Roig 11, 46010 Val&#232;ncia, Spain. jcalvete@ibv.csic.es.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Calvete
mesh_terms: D051722:ADAM Proteins / Q000235:genetics*; D000818:Animals; D019143:Evolution, Molecular; D005091:Exons; D050939:Gene Fusion; D016678:Genome; D007438:Introns; D005810:Multigene Family; D009154:Mutation; D022821:RNA Splice Sites; D030162:Reptilian Proteins / Q000235:genetics*; D014757:Viper Venoms / Q000145:classification / Q000235:genetics*; D017819:Viperidae / Q000145:classification / Q000235:genetics*
chemical_list: D022821:RNA Splice Sites; D030162:Reptilian Proteins; D014757:Viper Venoms; D051722:ADAM Proteins
keywords: PI-SVMP; PII-SVMP; Snake venom toxin multi-gene family; gene duplication; genomic organization of SVMP genes; intronic retroelements; intronization; snake venom metalloproteinase