Addiction to nicotine, and possibly other tobacco constituents, is a major factor that contributes to the difficulties smokers face when attempting to quit smoking. Amongst the various subtypes of nicotinic acetylchol...Addiction to nicotine, and possibly other tobacco constituents, is a major factor that contributes to the difficulties smokers face when attempting to quit smoking. Amongst the various subtypes of nicotinic acetylcholine receptors (nAChRs), the α4β2 subtype plays an important role in mediating the addiction process. The characterization of human α4β2-ligand binding interactions provides a molecular framework for understanding ligand-receptor interactions, rendering insights into mechanisms of nicotine addiction and may furnish a tool for efficiently identifying ligands that can bind the nicotine receptor. Therefore, we constructed a homology model of human α4β2 nAChR and performed molecular docking and molecular dynamics (MD) simulations to elucidate the potential human α4β2-ligand binding modes for eleven compounds known to bind to this receptor. Residues V96, L97 and F151 of the α4 subunit and L111, F119 and F121 of the β2 subunit were found to be involved in hydrophobic interactions while residues S153 and W154 of the α4 subunit were involved in the formation of hydrogen bonds between the receptor and respective ligands. The homology model and its eleven ligand-bound structures will be used to develop a virtual screening program for identifying tobacco constituents that are potentially addictive.展开更多
Despite the urgent need for conservation consideration,strategic action plans for the preservation of the Asian honeybee,Apis cerana Fabricius,1793,remain lacking.Both the convergent and divergent adaptations of this ...Despite the urgent need for conservation consideration,strategic action plans for the preservation of the Asian honeybee,Apis cerana Fabricius,1793,remain lacking.Both the convergent and divergent adaptations of this widespread insect have led to confusing phenotypical traits and inconsistent infraspecific taxonomy.Unclear subspecies boundaries pose a significant challenge to honeybee conservation efforts,as it is difficult to effectively prioritize conservation targets without a clear understanding of subspecies identities.Here,we investigated genome variations in 362 worker bees representing almost all populations of mainland A.cerana to understand how evolution has shaped its population structure.Whole-genome single nucleotide polymorphisms(SNPs)based on nuclear sequences revealed eight putative subspecies,with all seven peripheral subspecies exhibiting mutually exclusive monophyly and distinct genetic divergence from the widespread central subspecies.Our results demonstrated that most classic morphological traits,including body size,were related to the climatic variables of the local habitats and did not reflect the true evolutionary history of the organism.Thus,such morphological traits were not suitable for subspecific delineation.Conversely,wing vein characters showed relative independence to the environment and supported the subspecies boundaries inferred from nuclear genomes.Mitochondrial phylogeny further indicated that the present subspecies structure was a result of multiple waves of population divergence from a common ancestor.Based on our findings,we propose that criteria for subspecies delineation should be based on evolutionary independence,trait distinction,and geographic isolation.We formally defined and described eight subspecies of mainland A.cerana.Elucidation of the evolutionary history and subspecies boundaries enables a customized conservation strategy for both widespread and endemic honeybee conservation units,guiding colony introduction and breeding.展开更多
Bumblebees are important pollinators for many natural and agricultural systems in temperate regions.Interspecific and intraspecific variation in floral resource preferences have been proposed to influence bumblebee co...Bumblebees are important pollinators for many natural and agricultural systems in temperate regions.Interspecific and intraspecific variation in floral resource preferences have been proposed to influence bumblebee community structure.In particular,sexual dimorphism is a major source of intraspecific niche variation.Although interspecific resource partitioning is well studied,few studies have explored the intraspecific dynamics between workers and males.Here,we report a study on a total of 11528 workers and 2220 males of 14 bumblebee species recorded over 5 years in the Hengduan Mountains of Southwest China.We first compared the potential for interspecific and intraspecific competition between workers and males using visitation records and resource partitioning indices(overlap index).We then evaluated the influence of nectar traits on flower preference,including nectar volume and the levels of hexose,sucrose and 10 essential amino acids(EAAs).We found that the niche overlap between intraspecific workers and males was higher than that between different species,and temporal overlap alone did not strongly determine diet overlap.Males of most species preferred flowers with high levels of EAAs and hexose,whereas workers of some species preferred flowers with high nectar volume and sucrose levels.This study suggests that there is floral resource partitioning among bumblebee species,and between workers and males,which may play a key role in alleviating interspecific and intraspecific competition.These findings also provide a useful guide for which kinds of plants might be most valuable for bumblebees,especially the understudied males,in this biodiversity hotspot.展开更多
How many species of life are there on Earth?This is a question that we want to know but cannot yet answer.Some scholars speculate that the number of species may reach 2.2 billion when considering cryptic diversity and...How many species of life are there on Earth?This is a question that we want to know but cannot yet answer.Some scholars speculate that the number of species may reach 2.2 billion when considering cryptic diversity and that each morphology-based insect species may contain an average of 3.1 cryptic species.With nearly two million described species,such high estimates of cryptic diversity would suggest that cryptic species are widespread.The development of molecular species delimitation has led to the discovery of a large number of cryptic species,and cryptic biodiversity has gradually entered ourfield of vision and attracted more attention.This paper introduces the concept of cryptic species,how they evolve,and methods by which they may be discovered and confirmed,and provides theoretical and methodological guidance for the study of hidden species.A workflow of how to confirm cryptic species is provided.In addition,the importance and reliability of multi-evidence-based integrated taxonomy are reaffirmed as a way to better standardize decision-making processes.Special focus on cryptic diversity and increased funding for taxonomy is needed to ensure that cryptic species in hyperdiverse groups are discoverable and described.An increased focus on cryptic species in the future will naturally arise as more difficult groups are studied,and thereby,we mayfinally better understand the rules governing the evolution and maintenance of cryptic biodiversity.展开更多
文摘Addiction to nicotine, and possibly other tobacco constituents, is a major factor that contributes to the difficulties smokers face when attempting to quit smoking. Amongst the various subtypes of nicotinic acetylcholine receptors (nAChRs), the α4β2 subtype plays an important role in mediating the addiction process. The characterization of human α4β2-ligand binding interactions provides a molecular framework for understanding ligand-receptor interactions, rendering insights into mechanisms of nicotine addiction and may furnish a tool for efficiently identifying ligands that can bind the nicotine receptor. Therefore, we constructed a homology model of human α4β2 nAChR and performed molecular docking and molecular dynamics (MD) simulations to elucidate the potential human α4β2-ligand binding modes for eleven compounds known to bind to this receptor. Residues V96, L97 and F151 of the α4 subunit and L111, F119 and F121 of the β2 subunit were found to be involved in hydrophobic interactions while residues S153 and W154 of the α4 subunit were involved in the formation of hydrogen bonds between the receptor and respective ligands. The homology model and its eleven ligand-bound structures will be used to develop a virtual screening program for identifying tobacco constituents that are potentially addictive.
基金supported by the National Natural Science Foundation(NSF)of China(32270475)Program of Ministry of Science and Technology of China(2018FY100403)+3 种基金National Special Support Program for High-level Talents(Ten-Thousand Talents Program)2115 Talent Development Program of China Agricultural University through Xin Z.S.L.is supported by Funds for International Cooperation and Exchange of the National Natural Science Foundation of China(3211001043)supported by the NSF of China(31470123)Jilin Science and Technology Program(20030561)through X.L.S.H.P.is supported by the National Mission on Himalayan Studies(NMHS)-Almora,Ministry of Environment,Forest and Climate Change,Government of India,through grant GBPNI/NMHS-2017-18/MG-12。
文摘Despite the urgent need for conservation consideration,strategic action plans for the preservation of the Asian honeybee,Apis cerana Fabricius,1793,remain lacking.Both the convergent and divergent adaptations of this widespread insect have led to confusing phenotypical traits and inconsistent infraspecific taxonomy.Unclear subspecies boundaries pose a significant challenge to honeybee conservation efforts,as it is difficult to effectively prioritize conservation targets without a clear understanding of subspecies identities.Here,we investigated genome variations in 362 worker bees representing almost all populations of mainland A.cerana to understand how evolution has shaped its population structure.Whole-genome single nucleotide polymorphisms(SNPs)based on nuclear sequences revealed eight putative subspecies,with all seven peripheral subspecies exhibiting mutually exclusive monophyly and distinct genetic divergence from the widespread central subspecies.Our results demonstrated that most classic morphological traits,including body size,were related to the climatic variables of the local habitats and did not reflect the true evolutionary history of the organism.Thus,such morphological traits were not suitable for subspecific delineation.Conversely,wing vein characters showed relative independence to the environment and supported the subspecies boundaries inferred from nuclear genomes.Mitochondrial phylogeny further indicated that the present subspecies structure was a result of multiple waves of population divergence from a common ancestor.Based on our findings,we propose that criteria for subspecies delineation should be based on evolutionary independence,trait distinction,and geographic isolation.We formally defined and described eight subspecies of mainland A.cerana.Elucidation of the evolutionary history and subspecies boundaries enables a customized conservation strategy for both widespread and endemic honeybee conservation units,guiding colony introduction and breeding.
基金supported by the National Natural Science Foundation of China(grants 31800194 and 32170241 to ZMY,grants 31970253 and 32270243 to CFY)the Strategic Priority Research Program of the Chinese Academy of Sciences(grant XDB31010000 to QFW)+1 种基金supported by the Key Laboratory of the Zoological Systematics and Evolution of the Chinese Academy of Sciences(grant 2008DP173354)supported by the Chinese Academy of Science's President's International Fellowship Initiative(PIFI)(grant 2024PVC0046).
文摘Bumblebees are important pollinators for many natural and agricultural systems in temperate regions.Interspecific and intraspecific variation in floral resource preferences have been proposed to influence bumblebee community structure.In particular,sexual dimorphism is a major source of intraspecific niche variation.Although interspecific resource partitioning is well studied,few studies have explored the intraspecific dynamics between workers and males.Here,we report a study on a total of 11528 workers and 2220 males of 14 bumblebee species recorded over 5 years in the Hengduan Mountains of Southwest China.We first compared the potential for interspecific and intraspecific competition between workers and males using visitation records and resource partitioning indices(overlap index).We then evaluated the influence of nectar traits on flower preference,including nectar volume and the levels of hexose,sucrose and 10 essential amino acids(EAAs).We found that the niche overlap between intraspecific workers and males was higher than that between different species,and temporal overlap alone did not strongly determine diet overlap.Males of most species preferred flowers with high levels of EAAs and hexose,whereas workers of some species preferred flowers with high nectar volume and sucrose levels.This study suggests that there is floral resource partitioning among bumblebee species,and between workers and males,which may play a key role in alleviating interspecific and intraspecific competition.These findings also provide a useful guide for which kinds of plants might be most valuable for bumblebees,especially the understudied males,in this biodiversity hotspot.
基金supported by the Ningxia Hui Autonomous Region Agricultural Science and Technology Independent Innovation Fund(NGSB20211405)Key Laboratory of the Zoological Systematics and Evolution of the Chinese Academy of Sciences(2008DP173354)the Survey of Wildlife Resources in Key Areas of Tibet(ZL202203601).
文摘How many species of life are there on Earth?This is a question that we want to know but cannot yet answer.Some scholars speculate that the number of species may reach 2.2 billion when considering cryptic diversity and that each morphology-based insect species may contain an average of 3.1 cryptic species.With nearly two million described species,such high estimates of cryptic diversity would suggest that cryptic species are widespread.The development of molecular species delimitation has led to the discovery of a large number of cryptic species,and cryptic biodiversity has gradually entered ourfield of vision and attracted more attention.This paper introduces the concept of cryptic species,how they evolve,and methods by which they may be discovered and confirmed,and provides theoretical and methodological guidance for the study of hidden species.A workflow of how to confirm cryptic species is provided.In addition,the importance and reliability of multi-evidence-based integrated taxonomy are reaffirmed as a way to better standardize decision-making processes.Special focus on cryptic diversity and increased funding for taxonomy is needed to ensure that cryptic species in hyperdiverse groups are discoverable and described.An increased focus on cryptic species in the future will naturally arise as more difficult groups are studied,and thereby,we mayfinally better understand the rules governing the evolution and maintenance of cryptic biodiversity.
