title: Proteomic comparisons of venoms of long-term captive and recently wild-caught Eastern brown snakes (Pseudonaja textilis) indicate venom does not change due to captivity.
abstract: Snake venom is a highly variable phenotypic character, and its variation and rapid evolution are important because of human health implications. Because much snake antivenom is produced from captive animals, understanding the effects of captivity on venom composition is important. Here, we have evaluated toxin profiles from six long-term (LT) captive and six recently wild-caught (RC) eastern brown snakes, Pseudonaja textilis, utilizing gel electrophoresis, HPLC-MS, and shotgun proteomics. We identified proteins belonging to the three-finger toxins, group C prothrombin activators, Kunitz-type serine protease inhibitors, and phospholipases A2, among others. Although crude venom HPLC analysis showed LT snakes to be higher in some small molecular weight toxins, presence/absence patterns showed no correlation with time in captivity. Shotgun proteomics indicated the presence of similar toxin families among individuals but with variation in protein species. Although no venom sample contained all the phospholipase A2 subunits that form the textilotoxin, all did contain both prothrombin activator subunits. This study indicates that captivity has limited effects on venom composition, that venom variation is high, and that venom composition may be correlated to geographic distribution.
  
  
  
  Through proteomic comparisons, we show that protein variation within LT and RC groups of snakes (Pseudonaja textilis) is high, thereby resulting in no discernible differences in venom composition between groups. We utilize complementary techniques to characterize the venom proteomes of 12 individual snakes from our study area, and indicate that individuals captured close to one another have more similar venom gel electrophoresis patterns than those captured at more distant locations. These data are important for understanding natural variation in and potential effects of captivity on venom composition.
authors.affiliation: Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 117543, Singapore; Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, USA.
authors.forename: Ryan J R
authors.initials: RJ
authors.lastname: McCleary
authors.affiliation: Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 117543, Singapore.
authors.forename: Sindhuja
authors.initials: S
authors.lastname: Sridharan
authors.affiliation: Venom Supplies Pty. Ltd., P.O. Box 547, Tanunda, South Australia 5352, Australia.
authors.forename: Nathan L
authors.initials: NL
authors.lastname: Dunstan
authors.affiliation: Venom Supplies Pty. Ltd., P.O. Box 547, Tanunda, South Australia 5352, Australia.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Mirtschin
authors.affiliation: Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 117543, Singapore; Singapore Eye Research Institute, The Academia, 20 College Road, Discovery Tower Level 6, Singapore 169856, Singapore. Electronic address: dbskinim@nus.edu.sg.
authors.forename: R Manjunatha
authors.initials: RM
authors.lastname: Kini
mesh_terms: D000828:Animal Population Groups; D000818:Animals; D004546:Elapid Venoms / Q000737:chemistry*; D017815:Elapidae; D054467:Phospholipases A2 / Q000032:analysis; D040901:Proteomics / Q000295:instrumentation / Q000379:methods*; D011516:Prothrombin / Q000819:agonists; D015842:Serine Proteinase Inhibitors / Q000032:analysis; D013312:Stress, Physiological
chemical_list: D004546:Elapid Venoms; D015842:Serine Proteinase Inhibitors; C037525:textilotoxin; D011516:Prothrombin; D054467:Phospholipases A2
keywords: Phospholipases A(2); Snake prothrombin activators; Snakes in captivity; Three-finger toxins; Venom geographic variation; Venom variation