It is hypothesized that protease inhibitors play an essential role in survival of venomous animals through protecting peptide/protein toxins from degradation by proteases in their prey or predators. However, the biolo...It is hypothesized that protease inhibitors play an essential role in survival of venomous animals through protecting peptide/protein toxins from degradation by proteases in their prey or predators. However, the biological function of protease inhibitors in scorpion venoms remains unknown. In the present study, a trypsin inhibitor was purified and characterized from the venom of scorpion Mesobuthus eupeus, which enhanced the biological activities of crude venom components in mice when injected in combination with crude venom. This protease inhibitor, named Me KTT-1, belonged to Kunitz-type toxins subfamily. Native Me KTT-1 selectively inhibited trypsin with a K_i value of 130 nmol×L^(–1). Furthermore, Me KTT-1 was shown to be a thermo-stable peptide. In animal behavioral tests, Me KTT-1 prolonged the pain behavior induced by scorpion crude venom, suggesting that protease inhibitors in scorpion venom inhibited proteases and protect the functionally important peptide/protein toxins from degradation, consequently keeping them active longer. In conclusion, this was the first experimental evidence about the natural existence of serine protease inhibitor in the venom of scorpion Mesobuthus eupeus, which preserved the activity of venom components, suggests that scorpions may use protease inhibitors for survival.展开更多
Reliable delimitation of venomous scorpions is not only consequential to toxicological studies but also instructive to conservation and exploration of these important medical resources.In the present study,we delimite...Reliable delimitation of venomous scorpions is not only consequential to toxicological studies but also instructive to conservation and exploration of these important medical resources.In the present study,we delimited species boundary for the the Przewalski’s scorpion from arid northwest China through a combined approach employing phylogenetic analysis,ecological niche modeling and morphological comparison.Our results indicate that the Przewalski’s scorpion represent an independent taxonomic unit and should be recognized as full species rank,Mesobuthus przewalskii stat.nov.This species and the Chinese scorpion M.martensii represent the eastern members of the M.caucasicus species group which manifests a trans-Central Asia distribution across the Tianshan Mountains range.We also discussed the likely geographic barrier and climatic boundary that demarcate distributional range of the the Przewalski’s scorpion.展开更多
A comprehensive understanding of phylogeography requires the integration of knowledge across different organisms,ecosystems,and geographic regions.However,a critical knowledge gap exists in the arid biota of the vast ...A comprehensive understanding of phylogeography requires the integration of knowledge across different organisms,ecosystems,and geographic regions.However,a critical knowledge gap exists in the arid biota of the vast Asian drylands.To narrow this gap,here we test an“out-of-Central Asia”hypothesis for the desert scorpion Mesobuthus mongolicus by combining Bayesian phylogeographic reconstruction and ecological niche modeling.Phylogenetic analyses of one mitochondrial and three nuclear loci and molecular dating revealed that M.mongolicus represents a coherent lineage that diverged from its most closely related lineage in Central Asia about 1.36 Ma and underwent radiation ever since.Bayesian phylogeographic reconstruction indicated that the ancestral population dispersed from Central Asia gradually eastward to the Gobi region via the Junggar Basin,suggesting that the Junggar Basin has severed as a corridor for Quaternary faunal exchange between Central Asia and East Asia.Two major dispersal events occurred probably during interglacial periods(around 0.8 and 0.4 Ma,respectively)when climatic conditions were analogous to present-day status,under which the scorpion achieved its maximum distributional range.M.mongolicus underwent demographic expansion during the Last Glacial Maximum,although the predicted distributional areas were smaller than those at present and during the Last Interglacial.Development of desert ecosystems in northwest China incurred by intensified aridification might have opened up empty habitats that sustained population expansion.Our results extend the spatiotemporal dimensions of trans-Eurasia faunal exchange and suggest that species’adaptation is an important determinant of their phylogeographic and demographic responses to climate changes.展开更多
基金supported by MOST(2013CB911300,2010CB529800)NSFC(Nos.31025025,31025025,U1132601,31200590)+1 种基金CAS(SAJC201308)Yunnan Province(2011CI139,2012BC009)
文摘It is hypothesized that protease inhibitors play an essential role in survival of venomous animals through protecting peptide/protein toxins from degradation by proteases in their prey or predators. However, the biological function of protease inhibitors in scorpion venoms remains unknown. In the present study, a trypsin inhibitor was purified and characterized from the venom of scorpion Mesobuthus eupeus, which enhanced the biological activities of crude venom components in mice when injected in combination with crude venom. This protease inhibitor, named Me KTT-1, belonged to Kunitz-type toxins subfamily. Native Me KTT-1 selectively inhibited trypsin with a K_i value of 130 nmol×L^(–1). Furthermore, Me KTT-1 was shown to be a thermo-stable peptide. In animal behavioral tests, Me KTT-1 prolonged the pain behavior induced by scorpion crude venom, suggesting that protease inhibitors in scorpion venom inhibited proteases and protect the functionally important peptide/protein toxins from degradation, consequently keeping them active longer. In conclusion, this was the first experimental evidence about the natural existence of serine protease inhibitor in the venom of scorpion Mesobuthus eupeus, which preserved the activity of venom components, suggests that scorpions may use protease inhibitors for survival.
基金founded by the Natural Science Foundation of China(31772435)
文摘Reliable delimitation of venomous scorpions is not only consequential to toxicological studies but also instructive to conservation and exploration of these important medical resources.In the present study,we delimited species boundary for the the Przewalski’s scorpion from arid northwest China through a combined approach employing phylogenetic analysis,ecological niche modeling and morphological comparison.Our results indicate that the Przewalski’s scorpion represent an independent taxonomic unit and should be recognized as full species rank,Mesobuthus przewalskii stat.nov.This species and the Chinese scorpion M.martensii represent the eastern members of the M.caucasicus species group which manifests a trans-Central Asia distribution across the Tianshan Mountains range.We also discussed the likely geographic barrier and climatic boundary that demarcate distributional range of the the Przewalski’s scorpion.
基金This study was supported by the National Natural Science Foundation of China(grant nos.31772435,32170455)C.-M.S.is also supported by a starting fund from Hebei Agricultural University and the State Key Laboratory of North China Crop Improvement and Regulation(YJ2020028).
文摘A comprehensive understanding of phylogeography requires the integration of knowledge across different organisms,ecosystems,and geographic regions.However,a critical knowledge gap exists in the arid biota of the vast Asian drylands.To narrow this gap,here we test an“out-of-Central Asia”hypothesis for the desert scorpion Mesobuthus mongolicus by combining Bayesian phylogeographic reconstruction and ecological niche modeling.Phylogenetic analyses of one mitochondrial and three nuclear loci and molecular dating revealed that M.mongolicus represents a coherent lineage that diverged from its most closely related lineage in Central Asia about 1.36 Ma and underwent radiation ever since.Bayesian phylogeographic reconstruction indicated that the ancestral population dispersed from Central Asia gradually eastward to the Gobi region via the Junggar Basin,suggesting that the Junggar Basin has severed as a corridor for Quaternary faunal exchange between Central Asia and East Asia.Two major dispersal events occurred probably during interglacial periods(around 0.8 and 0.4 Ma,respectively)when climatic conditions were analogous to present-day status,under which the scorpion achieved its maximum distributional range.M.mongolicus underwent demographic expansion during the Last Glacial Maximum,although the predicted distributional areas were smaller than those at present and during the Last Interglacial.Development of desert ecosystems in northwest China incurred by intensified aridification might have opened up empty habitats that sustained population expansion.Our results extend the spatiotemporal dimensions of trans-Eurasia faunal exchange and suggest that species’adaptation is an important determinant of their phylogeographic and demographic responses to climate changes.
