Objective To identify new genes required for neurosecretory control of aging in C. elegans. Methods In view of the importance of nervous system in aging regulation, we performed the screen for genes involved in the ag...Objective To identify new genes required for neurosecretory control of aging in C. elegans. Methods In view of the importance of nervous system in aging regulation, we performed the screen for genes involved in the aging regulation from genetic loci encoding synaptic proteins by lifespan assay and accumulation of lipofuscin autofluorescence. We further investigated the dauer formation phenotypes of their corresponding mutants and whether they were possibly up-regulated by the insulin-like signaling pathway. Results The genetic loci of unc-10, syd-2, hlb-1, dlk-1, mkk-4, scd- 2, snb-1, ric-4, nrx-1, unc-13, sbt-1 and unc-64 might be involved in the aging control. In addition, functions of unc-10, syd-2, hlb-1, dlk-1, mkk-4, scd-2, snb-1, ric-4 and nrx-1 in regulating aging may be opposite to those of unc-13, sbt-1 and unc-64. The intestinal autofluorescence assay further indicated that the identified long-lived and short-lived mutants were actually due to the suppressed or accelerated aging. Among the identified genes, syd-2, hlb-1, mkk-4, scd-2, snb-1, ric-4 and unc-64 were also involved in the control of dauer formation. Moreover, daf-2 mutation positively regulated the expression of syd-2 and hlb-1, and negatively regulated the expression of mkk-4, nrx-1, ric-4, sbt-1, rpm-1, unc-10, dlk- 1 and unc-13. The daf-16 mutation positively regulated the expression of syd-2 and hlb-1, and negatively regulated the expression of mkk-4, nrx-1, sbt-1, rpm-1, unc-10, dlk-1 and unc-13. Conclusion These data suggest the possibly important status of the synaptic transmission to the animal＇ s life-span control machinery, as well as the dauer formation control.展开更多
The living morphology and infraciliature of two rare marine ciliates, Placussalinus Dietz, 1964 and Strombidium apolatum Wilbert and Song, 2005, collected from the coastalwaters near Qingdao, China, were investigated ...The living morphology and infraciliature of two rare marine ciliates, Placussalinus Dietz, 1964 and Strombidium apolatum Wilbert and Song, 2005, collected from the coastalwaters near Qingdao, China, were investigated by in vivo observation and protargol impregnationtechnique. The improved diagnosis for Placus salinus is as follows: medium-sized marine Placus, invivo (50-60) μm X (30-40) μm; cell elliptical to barrel-shaped; 28-31 somatic kineties; singlemacronucleus usually ellipsoid and one micronucleus located in the indention of the macronucleus;one contractile vacuole posteriorly positioned. Strombidium apolatum is characterized by: marinestrombidium (40-60) μm X (30-45) μm in vivo, cordiform in shape with somewhat pointed posteriorend and conspicuous apical protrusion; extrusomes prominent, about 15 μm in length and evenlyarranged along the circle kinety; about 16 collar and 5-6 buccal membranelles; one elongatemacronucleus and one micronucleus; circle and ventral kineties consisting of about 53 and 45dikinetids respectively.展开更多
The 18S ribosomal DNA gene （18S rDNA） sequences （approxtmately 1300 bp in length） were amplified from the DNA extracted from the free-living marine nematodes collected from the inter-tidal sediment of Qingdao coas...The 18S ribosomal DNA gene （18S rDNA） sequences （approxtmately 1300 bp in length） were amplified from the DNA extracted from the free-living marine nematodes collected from the inter-tidal sediment of Qingdao coast in bulk with nematode specific primers. The PCR products were cloned, re-amplified, digested with Rsa I and Hin61 restriction endonucleases and separated in agarose gel. Among 17 restriction fragment length types, types 1, 2 and 6 covered 61.2%, 14.4% and 9.3% of the clones analyzed, respectively, while the remaining 14 only covered 21 clones, which accounted for 15.1% of the total. Twenty-four representative clones were sequenced and phylogenetically analyzed by referring to those currently available in RDP and GenBank databases. Although it was hard to assign these sequences to known species or genera due to the lack of the 18S rDNA sequence data of known marine free-living nematodes, the obtained sequences were assigned to the nematodes of Adenophorea. Among them, twelve sequences were close to Pontonema vulgate and Adoncholaimus sp., four to Daptonema procerus and two （identical） to Enoplus brews. Our results showed that free-living marine nematode diversities could be determined by PCR retrieving and analysis of the 18S rDNA sequences and an 18S rDNA sequence could be assigned to a species or a genus only if the 18S rDNA sequences of the free-living marine nematodes were accumulated to some extent.展开更多
The morphology and infraciliature of a new marine colepid ciliate, A＇pocoleps magnus gen. nov., spec. nov., are de- scribed based on living observations and silver impregnations. The new genus Apocoleps is characteri...The morphology and infraciliature of a new marine colepid ciliate, A＇pocoleps magnus gen. nov., spec. nov., are de- scribed based on living observations and silver impregnations. The new genus Apocoleps is characterized by having 8 （vs. 6 in most other related genera） armour tiers, spines at both ends of the cell, 3 adoral organelles and plates with 4 reniform uni-windows. Apo- coleps magnus spec. nov. is defined by the following features： body elongated and slightly curved, about 100-120p.mx 3545 lam in vivo; anterior tertiary tier plate with four uni-windows, most secondary and main tier plates with four uni-windows, posterior tertiary tier plate with two uni-windows; left plate margin slightly serrated; on average 23 transverse and 22 longitudinal ciliary rows; one terminal contractile vacuole; marine habitat.展开更多
Measuring fitness is essential for understanding the potential impacts of hybridisation between transgenic crops and their wild relatives. Transgenic CrylAc cotton Gossypium hirsutum and G. barbadense hybridise, the l...Measuring fitness is essential for understanding the potential impacts of hybridisation between transgenic crops and their wild relatives. Transgenic CrylAc cotton Gossypium hirsutum and G. barbadense hybridise, the latter being valued as backyard cotton and an important genetic resource. G. barbadense was outcrossed to G. hirsutum containing the gene CrylAc and the isoline and the offspring evaluated for fitness as a measure of resistance to common pests and other growth parameters, Resistance to Pectinophora gossypiella and Alabama argillacea were greater in transgenic plants. Number of seeds per plant was higher in the F1 hybrids and G. hirsutum, F2 populations were intermediary; G. barbadense produced the least seeds per plant during the period of analysis. Anthesis of the first flower and opening of the first boll occurred earlier for G. hirsutum and Ft hybrids than F2; latest for G. barbadense. The observed-performance of resistance to the worms in the hybrids suggests that among FI and F2 populations transgenic hybrids may exhibit a competitive advantage over non-transgenic plants as a result of gene flow.展开更多
OBJECTIVE: To identify genotype of eight strains of Orientia tsutsugamushi (O. tsutsugamushi) isolated from Nan Peng Lie Islands in China and establish tsutsugamushi disease nature foci for this region. METHODS: The n...OBJECTIVE: To identify genotype of eight strains of Orientia tsutsugamushi (O. tsutsugamushi) isolated from Nan Peng Lie Islands in China and establish tsutsugamushi disease nature foci for this region. METHODS: The nested polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) were used. Three primers were selected from the DNA sequence of the gene encoding type-specific 56-kDa protein of the Karp strain. The positive products were digested by Hine II and Pst I, meanwhile profiles specific to each strain were analyzed. RESULTS: Three genotypes of O. tsutsugamushi including Karp, Kato and a new strain existed on Nan Peng Lie Islands. CONCLUSION: Nan Peng Lie Islands is tsutsugamushi disease nature foci.展开更多
OBJECTIVE: To investigate natural foci of tsutsugamushi disease whose incidence has increased in the Nan Peng Lie Islands in China, an area where this disease has not been previously recorded. METHODS: We recorded the...OBJECTIVE: To investigate natural foci of tsutsugamushi disease whose incidence has increased in the Nan Peng Lie Islands in China, an area where this disease has not been previously recorded. METHODS: We recorded the natural foci and isolated Orientia tsutsugamushi (O. tsutsugamushi) organism. We also studied prevention measures. RESULTS: These islands had the natural foci of a south subtropical zone. The main host and vector were Rattus norvegicus and Leptotrombidium deliens (L. deliens), respectively. The seasonal quantity trends of Rattus norvegicus and Leptotrombidium deliens were consistent with the incidence of human infection. Thirty-five strains of O. tsutsugamushi were isolated from Rattus norvegicus and L. deliense. The identification of 7 strains showed that most strains were Karp. Seroepidemiology showed a high prevalence of antibody against O. tsatsugamushi among local people. After prevention measures were used, the incidence was decreased. CONCLUSION: This was the first successful confirmation that the Nan Peng Lie Islands were natural foci of tsutsugamushi disease.展开更多
The conservation behavior framework is useful to identify key linkages between behavior and conservation practice. We apply this framework to a novel host-parasite system on the Galapagos Islands and ask if there have...The conservation behavior framework is useful to identify key linkages between behavior and conservation practice. We apply this framework to a novel host-parasite system on the Galapagos Islands and ask if there have been changes in parasite oviposition behavior and host mortality patterns across the first decade （2004-2013） of its known association. The Dipteran parasite Philornis downsi was first discovered in Darwin＇s finch nests in 1997 and is the biggest threat to the survival of Galapagos land birds. Host mortality has increased over the past decade. In Dipterans, pupation and pupae size are determined by access to host resources. Here, we test the hypothesis that P downsi flies are laying eggs in finch nests earlier in the nestling phase to maximize larval feeding time and therefore chance of pupation success before host death. The results show fewer 1st instar larvae later in the host nesting cycle in support of earlier egg laying behavior by female flies. Between 2004 and 2013, parasite intensity increased from -28 to -48 parasites per nest, host mortality increased from -50% to -90%, and host age at death decreased from -11 to -5 days. The earlier age at host death was correlated with fewer pupae （from -50% to -20%） and smaller pupae size （-10% decrease）. Changes in parasite behavior reveal new fitness costs to both the parasite and Darwin＇s finches. These findings un- derscore the need for urgent conservation action to save Darwin＇s finches from extinction due to a novel, lethal and introduced parasite [Current Zoology 60 （4）： 542-550, 2014].展开更多
文摘Objective To identify new genes required for neurosecretory control of aging in C. elegans. Methods In view of the importance of nervous system in aging regulation, we performed the screen for genes involved in the aging regulation from genetic loci encoding synaptic proteins by lifespan assay and accumulation of lipofuscin autofluorescence. We further investigated the dauer formation phenotypes of their corresponding mutants and whether they were possibly up-regulated by the insulin-like signaling pathway. Results The genetic loci of unc-10, syd-2, hlb-1, dlk-1, mkk-4, scd- 2, snb-1, ric-4, nrx-1, unc-13, sbt-1 and unc-64 might be involved in the aging control. In addition, functions of unc-10, syd-2, hlb-1, dlk-1, mkk-4, scd-2, snb-1, ric-4 and nrx-1 in regulating aging may be opposite to those of unc-13, sbt-1 and unc-64. The intestinal autofluorescence assay further indicated that the identified long-lived and short-lived mutants were actually due to the suppressed or accelerated aging. Among the identified genes, syd-2, hlb-1, mkk-4, scd-2, snb-1, ric-4 and unc-64 were also involved in the control of dauer formation. Moreover, daf-2 mutation positively regulated the expression of syd-2 and hlb-1, and negatively regulated the expression of mkk-4, nrx-1, ric-4, sbt-1, rpm-1, unc-10, dlk- 1 and unc-13. The daf-16 mutation positively regulated the expression of syd-2 and hlb-1, and negatively regulated the expression of mkk-4, nrx-1, sbt-1, rpm-1, unc-10, dlk-1 and unc-13. Conclusion These data suggest the possibly important status of the synaptic transmission to the animal＇ s life-span control machinery, as well as the dauer formation control.
基金supported by‘The National Science Foundation of China’(Nos.40376045,30430090)
文摘The living morphology and infraciliature of two rare marine ciliates, Placussalinus Dietz, 1964 and Strombidium apolatum Wilbert and Song, 2005, collected from the coastalwaters near Qingdao, China, were investigated by in vivo observation and protargol impregnationtechnique. The improved diagnosis for Placus salinus is as follows: medium-sized marine Placus, invivo (50-60) μm X (30-40) μm; cell elliptical to barrel-shaped; 28-31 somatic kineties; singlemacronucleus usually ellipsoid and one micronucleus located in the indention of the macronucleus;one contractile vacuole posteriorly positioned. Strombidium apolatum is characterized by: marinestrombidium (40-60) μm X (30-45) μm in vivo, cordiform in shape with somewhat pointed posteriorend and conspicuous apical protrusion; extrusomes prominent, about 15 μm in length and evenlyarranged along the circle kinety; about 16 collar and 5-6 buccal membranelles; one elongatemacronucleus and one micronucleus; circle and ventral kineties consisting of about 53 and 45dikinetids respectively.
基金This study was supported financially by the National Natural Science Foundation of China （No. 40176028）.
文摘The 18S ribosomal DNA gene （18S rDNA） sequences （approxtmately 1300 bp in length） were amplified from the DNA extracted from the free-living marine nematodes collected from the inter-tidal sediment of Qingdao coast in bulk with nematode specific primers. The PCR products were cloned, re-amplified, digested with Rsa I and Hin61 restriction endonucleases and separated in agarose gel. Among 17 restriction fragment length types, types 1, 2 and 6 covered 61.2%, 14.4% and 9.3% of the clones analyzed, respectively, while the remaining 14 only covered 21 clones, which accounted for 15.1% of the total. Twenty-four representative clones were sequenced and phylogenetically analyzed by referring to those currently available in RDP and GenBank databases. Although it was hard to assign these sequences to known species or genera due to the lack of the 18S rDNA sequence data of known marine free-living nematodes, the obtained sequences were assigned to the nematodes of Adenophorea. Among them, twelve sequences were close to Pontonema vulgate and Adoncholaimus sp., four to Daptonema procerus and two （identical） to Enoplus brews. Our results showed that free-living marine nematode diversities could be determined by PCR retrieving and analysis of the 18S rDNA sequences and an 18S rDNA sequence could be assigned to a species or a genus only if the 18S rDNA sequences of the free-living marine nematodes were accumulated to some extent.
基金supported by ‘the Natural Science Foundation of China’ (Project No. 30870264)the Darwin Initiative Programme (Project No. 14-015)
文摘The morphology and infraciliature of a new marine colepid ciliate, A＇pocoleps magnus gen. nov., spec. nov., are de- scribed based on living observations and silver impregnations. The new genus Apocoleps is characterized by having 8 （vs. 6 in most other related genera） armour tiers, spines at both ends of the cell, 3 adoral organelles and plates with 4 reniform uni-windows. Apo- coleps magnus spec. nov. is defined by the following features： body elongated and slightly curved, about 100-120p.mx 3545 lam in vivo; anterior tertiary tier plate with four uni-windows, most secondary and main tier plates with four uni-windows, posterior tertiary tier plate with two uni-windows; left plate margin slightly serrated; on average 23 transverse and 22 longitudinal ciliary rows; one terminal contractile vacuole; marine habitat.
文摘Measuring fitness is essential for understanding the potential impacts of hybridisation between transgenic crops and their wild relatives. Transgenic CrylAc cotton Gossypium hirsutum and G. barbadense hybridise, the latter being valued as backyard cotton and an important genetic resource. G. barbadense was outcrossed to G. hirsutum containing the gene CrylAc and the isoline and the offspring evaluated for fitness as a measure of resistance to common pests and other growth parameters, Resistance to Pectinophora gossypiella and Alabama argillacea were greater in transgenic plants. Number of seeds per plant was higher in the F1 hybrids and G. hirsutum, F2 populations were intermediary; G. barbadense produced the least seeds per plant during the period of analysis. Anthesis of the first flower and opening of the first boll occurred earlier for G. hirsutum and Ft hybrids than F2; latest for G. barbadense. The observed-performance of resistance to the worms in the hybrids suggests that among FI and F2 populations transgenic hybrids may exhibit a competitive advantage over non-transgenic plants as a result of gene flow.
文摘OBJECTIVE: To identify genotype of eight strains of Orientia tsutsugamushi (O. tsutsugamushi) isolated from Nan Peng Lie Islands in China and establish tsutsugamushi disease nature foci for this region. METHODS: The nested polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) were used. Three primers were selected from the DNA sequence of the gene encoding type-specific 56-kDa protein of the Karp strain. The positive products were digested by Hine II and Pst I, meanwhile profiles specific to each strain were analyzed. RESULTS: Three genotypes of O. tsutsugamushi including Karp, Kato and a new strain existed on Nan Peng Lie Islands. CONCLUSION: Nan Peng Lie Islands is tsutsugamushi disease nature foci.
文摘OBJECTIVE: To investigate natural foci of tsutsugamushi disease whose incidence has increased in the Nan Peng Lie Islands in China, an area where this disease has not been previously recorded. METHODS: We recorded the natural foci and isolated Orientia tsutsugamushi (O. tsutsugamushi) organism. We also studied prevention measures. RESULTS: These islands had the natural foci of a south subtropical zone. The main host and vector were Rattus norvegicus and Leptotrombidium deliens (L. deliens), respectively. The seasonal quantity trends of Rattus norvegicus and Leptotrombidium deliens were consistent with the incidence of human infection. Thirty-five strains of O. tsutsugamushi were isolated from Rattus norvegicus and L. deliense. The identification of 7 strains showed that most strains were Karp. Seroepidemiology showed a high prevalence of antibody against O. tsatsugamushi among local people. After prevention measures were used, the incidence was decreased. CONCLUSION: This was the first successful confirmation that the Nan Peng Lie Islands were natural foci of tsutsugamushi disease.
文摘The conservation behavior framework is useful to identify key linkages between behavior and conservation practice. We apply this framework to a novel host-parasite system on the Galapagos Islands and ask if there have been changes in parasite oviposition behavior and host mortality patterns across the first decade （2004-2013） of its known association. The Dipteran parasite Philornis downsi was first discovered in Darwin＇s finch nests in 1997 and is the biggest threat to the survival of Galapagos land birds. Host mortality has increased over the past decade. In Dipterans, pupation and pupae size are determined by access to host resources. Here, we test the hypothesis that P downsi flies are laying eggs in finch nests earlier in the nestling phase to maximize larval feeding time and therefore chance of pupation success before host death. The results show fewer 1st instar larvae later in the host nesting cycle in support of earlier egg laying behavior by female flies. Between 2004 and 2013, parasite intensity increased from -28 to -48 parasites per nest, host mortality increased from -50% to -90%, and host age at death decreased from -11 to -5 days. The earlier age at host death was correlated with fewer pupae （from -50% to -20%） and smaller pupae size （-10% decrease）. Changes in parasite behavior reveal new fitness costs to both the parasite and Darwin＇s finches. These findings un- derscore the need for urgent conservation action to save Darwin＇s finches from extinction due to a novel, lethal and introduced parasite [Current Zoology 60 （4）： 542-550, 2014].
