The pine wood nematode(PWN),Bursaphelenchus xylophilus(Steiner & Buhrer) Nickle,is the pathogen of pine wilt disease(PWD) which can devastate forests.PWN can be of hi gh or low severity and the mechanisms underlyi...The pine wood nematode(PWN),Bursaphelenchus xylophilus(Steiner & Buhrer) Nickle,is the pathogen of pine wilt disease(PWD) which can devastate forests.PWN can be of hi gh or low severity and the mechanisms underlying the differences in virulence are unclear.Therefore,it is necessary to study the relationship between differentiation of PWN severity and its resistance to the main defensive substances of pine species(i.e.,α-pinene and H_(2)O_(2)).The feeding rate and fecundity of PWN was examined at different levels of virulence under conditions of a-pinene and H_(2)O_(2) stress.Moreover,the expression patterns of the main resistance genes of PWN with different virulence were determined under conditions of α-pinene and H_(2)O_(2) stress.The feeding rate and fecundity of the high virulence strain AMA3 were higher than those of the low virulence strain YW4.The expression levels of the autophagy gene BxATG5,cytochrome P450 gene BxCYP33 D3,and glutathione S-transferase genes BxGST1 and BxGST3 in AMA3 increased significantly upon exposure to α-pinene for 2 h,while these genes showed smaller degrees of upregulation in YW4.Under conditions of H_(2)O_(2) stress,the expression levels of BxATG5,catalase genes Bxy-ctl-1 and Bxy-ctl-2,and the 2-cysteine peroxiredoxin gene BxPrx in AMA3 were higher than those in YW4.These findings suggest that high virulence PWN has greater resistance to pine defensive substances α-pinene and H_(2)O_(2) than low virulence PWN,and resistance genes mediate the differential resistance of PWN strains.This study will contribute to the clarification of the mechanism underlying virulence differentiation of PWN and will advance understanding of the pathogenic mechanism of PWD.展开更多
Painful stimuli elicit first-line reflexive defensive reactions and,in many cases,also evoke second-line recuperative behaviors,the latter of which reflects the sensing of tissue damage and the alleviation of sufferin...Painful stimuli elicit first-line reflexive defensive reactions and,in many cases,also evoke second-line recuperative behaviors,the latter of which reflects the sensing of tissue damage and the alleviation of suffering.The lateral parabrachial nucleus(lPBN),composed of external-(elPBN),dorsal-(dlPBN),and central/superior-subnuclei(jointly referred to as slPBN),receives sensory inputs from spinal projection neurons and plays important roles in processing affective information from external threats and body integrity disruption.However,the organizational rules of lPBN neurons that provoke diverse behaviors in response to different painful stimuli from cutaneous and deep tissues remain unclear.In this study,we used region-specific neuronal depletion or silencing approaches combined with a battery of behavioral assays to show that slPBN neurons expressing substance P receptor(NK1R)(lPBNNK1R)are crucial for driving pain-associated self-care behaviors evoked by sustained noxious thermal and mechanical stimuli applied to skin or bone/muscle,while elPBN neurons are dispensable for driving such reactions.Notably,lPBNNK1R neurons are specifically required for forming sustained somatic pain-induced negative teaching signals and aversive memory but are not necessary for fear-learning or escape behaviors elicited by external threats.Lastly,both lPBNNK1R and elPBN neurons contribute to chemical irritant-induced nocifensive reactions.Our results reveal the functional organization of parabrachial substrates that drive distinct behavioral outcomes in response to sustained pain versus external danger under physiological conditions.展开更多
Olfactory cues that indicate predation risk elicit a number of defensive behaviors in fishes, but whether they are sufficientto also induce morphological defenses has received little attention. Cichlids are characteri...Olfactory cues that indicate predation risk elicit a number of defensive behaviors in fishes, but whether they are sufficientto also induce morphological defenses has received little attention. Cichlids are characterized by a high level of morphologicalplasticity during development, and the few species that have been tested do exhibit defensive behaviors when exposed toalarm cues released from the damaged skin of conspecifics. We utilized young juvenile Nicaragua cichlids Hypsophrys nicaraguensisto test if the perception of predation risk from alarm cue (conspecific skin extract) alone induces an increased relativebody depth which is a defense against gape-limited predators. After two weeks of exposure, siblings that were exposed to conspecificalarm cue increased their relative body depth nearly double the amount of those exposed to distilled water (control) andzebrafish Danio rerio alarm cue. We repeated our measurements over the last two weeks (12 and 14) of cue exposure when thefish were late-stage juveniles to test if the rate of increase was sustained; there were no differences in final dimensions betweenthe three treatments. Our results show that 1) the Nicaragua cichlid has an innate response to conspecific alarm cue which is not ageneralized response to an injured fish, and 2) this innate recognition ultimately results in developing a deeper body at a stage ofthe life history where predation risk is展开更多
基金funded partly by the National Key Research and Development Program of China(No.2018YFD0600203)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)+1 种基金Innovation and Entrepreneurship Training Program for Students of Jiangsu Higher Education Institutions (SPITP)Innovation and Entrepreneurship Training Program for Students of Nanjing Forestry University (No.201710298047Z)。
文摘The pine wood nematode(PWN),Bursaphelenchus xylophilus(Steiner & Buhrer) Nickle,is the pathogen of pine wilt disease(PWD) which can devastate forests.PWN can be of hi gh or low severity and the mechanisms underlying the differences in virulence are unclear.Therefore,it is necessary to study the relationship between differentiation of PWN severity and its resistance to the main defensive substances of pine species(i.e.,α-pinene and H_(2)O_(2)).The feeding rate and fecundity of PWN was examined at different levels of virulence under conditions of a-pinene and H_(2)O_(2) stress.Moreover,the expression patterns of the main resistance genes of PWN with different virulence were determined under conditions of α-pinene and H_(2)O_(2) stress.The feeding rate and fecundity of the high virulence strain AMA3 were higher than those of the low virulence strain YW4.The expression levels of the autophagy gene BxATG5,cytochrome P450 gene BxCYP33 D3,and glutathione S-transferase genes BxGST1 and BxGST3 in AMA3 increased significantly upon exposure to α-pinene for 2 h,while these genes showed smaller degrees of upregulation in YW4.Under conditions of H_(2)O_(2) stress,the expression levels of BxATG5,catalase genes Bxy-ctl-1 and Bxy-ctl-2,and the 2-cysteine peroxiredoxin gene BxPrx in AMA3 were higher than those in YW4.These findings suggest that high virulence PWN has greater resistance to pine defensive substances α-pinene and H_(2)O_(2) than low virulence PWN,and resistance genes mediate the differential resistance of PWN strains.This study will contribute to the clarification of the mechanism underlying virulence differentiation of PWN and will advance understanding of the pathogenic mechanism of PWD.
基金supported by the Shenzhen Key Laboratory of Drug Addiction (ZDSYS20190902093601675)CAS Key Laboratory of Brain Connectome and Manipulation (2019DP173024)+2 种基金National Natural Science Foundation of China (82274358)Shenzhen-Hong Kong Institute of Brain ScienceGuangdong Basic and Applied Basic Research Foundation (2023B1515040009)
文摘Painful stimuli elicit first-line reflexive defensive reactions and,in many cases,also evoke second-line recuperative behaviors,the latter of which reflects the sensing of tissue damage and the alleviation of suffering.The lateral parabrachial nucleus(lPBN),composed of external-(elPBN),dorsal-(dlPBN),and central/superior-subnuclei(jointly referred to as slPBN),receives sensory inputs from spinal projection neurons and plays important roles in processing affective information from external threats and body integrity disruption.However,the organizational rules of lPBN neurons that provoke diverse behaviors in response to different painful stimuli from cutaneous and deep tissues remain unclear.In this study,we used region-specific neuronal depletion or silencing approaches combined with a battery of behavioral assays to show that slPBN neurons expressing substance P receptor(NK1R)(lPBNNK1R)are crucial for driving pain-associated self-care behaviors evoked by sustained noxious thermal and mechanical stimuli applied to skin or bone/muscle,while elPBN neurons are dispensable for driving such reactions.Notably,lPBNNK1R neurons are specifically required for forming sustained somatic pain-induced negative teaching signals and aversive memory but are not necessary for fear-learning or escape behaviors elicited by external threats.Lastly,both lPBNNK1R and elPBN neurons contribute to chemical irritant-induced nocifensive reactions.Our results reveal the functional organization of parabrachial substrates that drive distinct behavioral outcomes in response to sustained pain versus external danger under physiological conditions.
基金provided by the Undergraduate Research Opportunities Program of Boston University
文摘Olfactory cues that indicate predation risk elicit a number of defensive behaviors in fishes, but whether they are sufficientto also induce morphological defenses has received little attention. Cichlids are characterized by a high level of morphologicalplasticity during development, and the few species that have been tested do exhibit defensive behaviors when exposed toalarm cues released from the damaged skin of conspecifics. We utilized young juvenile Nicaragua cichlids Hypsophrys nicaraguensisto test if the perception of predation risk from alarm cue (conspecific skin extract) alone induces an increased relativebody depth which is a defense against gape-limited predators. After two weeks of exposure, siblings that were exposed to conspecificalarm cue increased their relative body depth nearly double the amount of those exposed to distilled water (control) andzebrafish Danio rerio alarm cue. We repeated our measurements over the last two weeks (12 and 14) of cue exposure when thefish were late-stage juveniles to test if the rate of increase was sustained; there were no differences in final dimensions betweenthe three treatments. Our results show that 1) the Nicaragua cichlid has an innate response to conspecific alarm cue which is not ageneralized response to an injured fish, and 2) this innate recognition ultimately results in developing a deeper body at a stage ofthe life history where predation risk is
