Venom composition of Trimeresurus albolabris, T. insularis, T. puniceus and T. purpureomaculatus from Indonesia

Background: Several studies have been published on the characterization of Trimeresurus venoms. However, there is still limited information concerning the venom composition of Trimeresurus species distributed throughout Indonesia, which contributes to significant snakebite envenomation cases. The present study describes a comparative on the composition of T. albolabris, T. insularis, T. puniceus, and T. purpureomaculatus venoms originated from Indonesia. Methods: Protein content in the venom of four Trimeresurus species was determined using Bradford assay, and the venom proteome was elucidated using one-dimension SDS PAGE nano-ESI- LCMS/MS shotgun proteomics. Results: The venom of T. albolabris contained the highest protein content of 11.1 mg/mL, followed by T. puniceus, T. insularis and T. purpureomaculatus venom with 10.7 mg/mL, 8.9 mg/mL and 5.54 mg/mL protein, respectively. In total, our venomic analysis identified 65 proteins belonging to 16 protein families in T. purpureomaculatus; 64 proteins belonging to 18 protein families in T. albolabris; 58 different proteins belonging to 14 protein families in T. puniceus; and 48 different proteins belonging to 14 protein familiesin T. insularis. Four major proteins identified in all venoms belonged to snake venom metalloproteinase, C-type lectin, snake venom serine protease, and phospholipase A2. There were 11 common proteins in all venoms, and T. puniceus venom has the highest number of unique proteins compared to the other three venoms. Cluster analysis of the proteins and venoms showed that T. puniceus venom has the most distinct venom composition. Conclusions: Overall, the results highlighted venom compositional variation of four Trimeresurus spp. from Indonesia. The venoms appear to be highly similar, comprising at least four protein families that correlate with venom's toxin properties and function. This study adds more information on venom variability among Trimeresurus species within the close geographic origin and may contribute to the development of optimum heterologous antivenom.(AU)

Molecular techniques for sex identification of captive birds.

BACKGROUND AND AIM: Many avian species are considered sexually monomorphic. In monomorphic bird species, especially in young birds, sex is difficult to identify based on an analysis of their external morphology. Accurate sex identification is essential for avian captive breeding and evolutionary studies. Methods with varying degrees of invasiveness such as vent sexing, laparoscopic surgery, steroid sexing, and chromosome inspection (karyotyping) are used for sex identification in monomorphic birds. This study aimed to assess the utility of a non-invasive molecular marker for gender identification in a variety of captive monomorphic birds, as a strategy for conservation. MATERIALS AND METHODS: DNA was isolated from feather samples from 52 individuals representing 16 species of 11 families indigenous to both Indonesia and elsewhere. We amplified the chromodomain helicase DNA-binding (CHD) gene using polymerase chain reaction with MP, NP, and PF primers to amplify introns with lengths that differ between the CHD-W and the CHD-Z genes, allowing sex discrimination because the W chromosome is exclusively present in females. RESULTS: Molecular bird sexing confirmed 33 females and 19 males with 100% accuracy. We used sequencing followed by alignment on one protected bird species (Probosciger aterrimus). CONCLUSION: Sex identification may be accomplished noninvasively in birds, because males only have Z sex chromosomes, whereas females have both Z and W chromosomes. Consequently, the presence of a W-unique DNA sequence identifies an individual as female. Sexing of birds is vital for scientific research, and to increase the success rate of conservation breeding programs.