留言板

尊敬的读者、作者、审稿人, 关于本刊的投稿、审稿、编辑和出版的任何问题, 您可以本页添加留言。我们将尽快给您答复。谢谢您的支持!

姓名
邮箱
手机号码
标题
留言内容
验证码

2004年  第25卷  第4期

显示方式:
研究论文
Effects of transgenic rice with simultaneously constitutive expression of chitinase (RCH10) and glucanase (Glu) on soil collembolan Folsomia candida,Folsomia fimetaria and Sinella curviseta,and enchytraedes Enchytraeus crypticus were studied.Both transgenic and non-transgenic materials of fresh seedling or dry mature rice were used in three experimental systems:Petri dishes,soil-litter microcosms for single species tests and soil-litter mesocosms for multispecies tests.The results showed:1)After 21 day exposure to the seeding materials in Petri dishes,the reproduction of F.candida fed with transgenic leaves and roots was significantly reduced by 45.5% (P<0.05) and 30.5% (P<0.05),respectively,compared to the control non-transgenic wild rice seedlings;2)After 21 day exposure in soil-litter microcosms,there was a weak reduction by 19.3% (P<0.05) of the reproduction of F.candida by transgenic mature dried residues in amounts corresponding to 30 g plant material kg[-1] soil;3)After 16 week incubation in soil-litter mesocosms,the reproduction of F.candida was significantly reduced by 19.4% by transgenic rice residues corresponding to the concentration of 30 g/kg soil;likewise,the reproduction of enchytrade E.crypticus was significantly reduced by 38.0%.On the contrary,however,the reproduction of S.curviseta was significantly increased by 84.8%.As for the pesticide positive control experiment,reproduction of F.candida was reduced linearly with concentration of the pesticide.Consequently,the transgenic rice influences reproduction or density of both soil Collembola and enchytraedes,but with decreasing for some species while increasing for other species in density.
The study of bellowing of Chinese alligators (Alligator sinensis) was carried out during the period of 2003 in Hongxing reservoir (30°46′N,118°41′E) of Xuancheng,Anhui,China.The reservoir contains a small group (8-10 individuals) of wild and reintroduced alligators.When the bellow was heard,we recorded the date,time and number of bellows,and the weather condition.The results showed that the Chinese alligator began to bellow in March,and ended in November.The bellowing varied markedly on an annual basis (χ[2] test:χ[2]=448.29,df=8,P<0.01).The Chinese alligator bellowed most frequently in June,which accounted for 26.0% of the annual total.There was a significant different in the frequency of alligator bellowing between the reproductive period and non reproductive period (Mann-Whitney U test:U=2.0,P<0.05).The average number of bellows per month was 128 (SD=71.11,n=4) during the reproduction period,and it was obviously higher than that during the non reproductive period.The frequency of bellows also varied significantly on a diurnal basis (χ[2]=233.18,df=17,P<0.01) with two obvious peaks at 6:00-7:00 and 10:00-11:00.The frequency of bellows differed significantly between 06:00-18:00 and 18:00-24:00 (U=12.5,P<0.05),and it was inversely related to the alligators activity.We observed no effect of weather conditions on the frequency of bellowing.Those results indicate that the Chinese alligators bellowing has a close relationship with the reproductive behavior in the wild.The bellowing is believed to play an important role for attracting the opposite sex during the mating period,and has close relationship with females protecting their eggs and young in the hatching period.Moreover,the bellowing has the function of territorial protection and possibly defense of food-resources.
The seed deposition pattern created by seed dispersers is important for plant,and ultimately may influence the regeneration of a plant species.In this study,a declining Chinese endemic plant,Quercus liaotungensis,was studied in Xiaolongmen Forestry Centre,a Nation Park of Beijing from Sept.to Oct.in 2000.Seeds post-dispersal experiments of Q.liaotungensis were conducted with four different treatments (four different kinds of predators:Invertebrates,Invertebrates+rodents,all predators,and all predators with litter covering) in two plots.Sound and invalid seeds were used in 40 treatments;and totally 800 (sound and invalid seeds were 400 respectively) seeds were set in two plots.All of treatments were investigated 9 times during the period of field work.In the two plots,no seeds were moved in all treatment 1.The difference of dispersal seeds was no significant between all treatment 2 (rodents+invertebrates) and all treatment 3 (all predators) (P>0.05);but the difference of seed dispersal was significant between in all treatment 2 and treatment 4,so did treatment 3 and treatment 4.The differences between sound seeds dispersal and invalid seeds dispersal were significant in all treatment 2 of two plots (Plot 1:t=2.407,P<0.05;Plot 2:t=2.65,P<0.05),so did all treatment 3 of two plots (t=3.209,P<0.05;t=3.029,P<0.05).Total gnawing of invalid seeds were much more than those of sound seeds in two plots (χ[2]=14.75,P<0.05;χ[2]=9.85,P<0.05).All of the results confirmed that the rodents in the area,particularly Apodemus peninsulae (74.4% of the community),were the principal post-dispersal predators;and indicated that the microenvironment could affect the speed of seed removal;and showed that the invertebrates and birds had not affection on the dispersal of ground seeds;and indicated that rodents were preferred to predate sound seeds and might judge the quality of the oaks.
Partial sequences of the D-loop and the complete sequences of cytochrome b gene (1140 bp) of the slow lorises (genus Nycticebus) were undertaken to investigate evolutionary relationships among species of Nycticebus.Sequence analysis results consistently provide new taxonomy evidence at the DNA level for supporting Ratajszczak and Groves viewpoint that N.intermedus is merely the adult of N.pygmaeus (Ratajszczak,1998;Groves,1971).Phylogenetic analysis was performed by means of the combined data and these two separate sequences data,respectively,by using various methods,supporting the same topology,in which genus Nycticebus was formed of two clusters.The first cluster was composed of N.pygmaeus,and the second cluster of N.coucang.It also could provide a new molecular genetic evidence to support the view that the genus comprises two species:N.coucang and N.pygmaeus.
Cytosolic Hsp70 genes of two peritrichous ciliates (Vorticella campanula & Carchesium polypinum) were partially sequenced and the lengths are 438 bp,both encoding 146 amino acids.Using bacteria as the outgroup,the phylogenetic trees were constructed based on cytosolic Hsp70 amino acid sequences by maximum-likelihood (ML) and neighbor-joining (NJ) methods.The topology that V.campanula clustered with C.polypinum,and then formed a sister clade with another two species in Oligohymenophorea (Tetrahymena thermophila & Paramecium tetraurelia),suggested the monophyly of the peritrichs and their phylogenetic placement in the class Oligohymenophorea.
The geographical distribution of Galliformes in Hebei Province was analyzed by use of the correlative references of the distribution.The RS image was digitized to the vegetation map and the geomorphologic map utilizing the drawing function of GIS techniques.The dot distribution of the Galliformes was drawn with GIS techniques from the records of the references and the specimens and field survey.The suitable habitat of the Galliformes was defined through the relationship of birds and the environment.The suitable habitat types of every species was picked up and the distribution of the Galliformes in Hebei Province was forecasted by use of the function of analyzing,picking-up and splicing.The result shows that the Galliformes in Hebei Province mainly distribute in the Taihang Yanshan Mountains and the Bashang plateau,and that they can be divided into three types,namely,the species distributing in the whole province (Coturnix coturnix and Phasianus colchicus),the species distributing in the Taihang Yanshan Mountains and the Bashang plateau (Alectoris chukar,Perdix dauuricae and Pucrasia macrolopha),and the species distributing in specific parts (Lyrurus tetrix,Tetrao parvirostris,Bonasa bonasia and Crossoptilon mantchuricum).
We measured the density of the burrows of Phrynocephalus vlangalii at the Zoigê Wetland at elevation about,NW Sichuan,by the quadrate method,and the depth by digging and using a blanch of alpine willows in September 2002.The density of P.vlangalii burrows declined with the plant coverage (r=-0.81,P<0.01),P.vlangalii shows preference to the desert with low plant coverage and could be used as one of indicator species for desertification of grassland.The depth of dwelling burrows was ≥74 cm,which is beyond the layer of frozen earth,living in these burrows is a behavioral mechanism of P.vlangalii to protect themselves from extreme low temperature,and the burrows with depth <74 cm may be used only for avoiding predation during foraging.
Habitat utilization of root vole (Microtus oeconomus) was studied in the region of Haibei Alpine Meadow Ecosystem Research Station,the Chinese Academy of Sciences,from July to September of 2002 and 2003.Three indexes of activity intensities,runway length,runway branch number and burrow entrance number were used to estimate root vole s utilization intensities on four types of habitats,manual cultivated land,true meadow,swamp meadow and Dasiphora fruticosa shrub.It was same that three indexes of activity intensities trended in four types of habitats.The activity intensities of root vole on four types of habitats were in ascending order of the manual cultivated land,true meadow,swamp meadow and D.fruticosa shrub.Three indexes of activity intensities were different significantly between each two types of habitats,except the runway length and runway branch number between the true meadow and swamp meadow.Overall,the root vole preferred the dense microhabitat with abundant food resource and no existence of competitive rodents.
The inhibition of carboxylesterase (CarE) and acetylcholinesterase (AChE) in booklices by dichlorvos,paraoxon,chlorpyrifos and carbosulfan was studied.The results of bioassay revealed that these insecticides showed strong inhibition to Liposcelis spp,and L.bostrychophila was less sensitive than L.entomophila.CarE of L.bostrychophila was more susceptible to inhibition than that of L.entomophila only to dichlorvos.For the AChE,the four inhibitors showed strong inhibition to both L.bostrychophila and L.entomophila and had similar susceptibility tendency with CarE;and inhibition kinetics also indicated the similar tendency.The inhibition pattern for two species was simply tested by PAGE and it was obvious that the endurance of two psocids to these insecticides has no direct relevence with the sensitivity of CarE and AChE.The further study should be done to realize the real mechanism of endurance.
The methods of anatomy,histology,histo-chemistry and electron microscope were applied to study the morphology of head kidney in the southern catfish,Silurus meridionalis Chen.The two parts of head kidney are separated;and they arent joined with kidney.Head kidney consists of blood vessels and three regions:lymphocyte-aggregate region,granulocyte-aggregate region and endocrine tissue region.Its blood vessels include arteries and veins of head kidney,posterior cardinal veins,and branches of posterior cardinal veins.The cells of lymphocyte-aggregate region assemble and reticulate.There are big lymphocyte,litter lymphocyte,plasma cell,monocyte,melano-macrophage and red cell.They are stained the darkest in three regions of head kidney.The granulocyte-aggregate region is stained half tint.The endocrine tissue region is stained very undertone.There are 2 kinds of cells in the endocrine tissue region:inter-renal tissue cell and super-renal tissue cell (chromaffin cell).The inter-renal tissue cells are abundant in mitochondria and smooth endoplasmic reticulum,and a few secretive granules.The super-renal tissue cells distribute around posterior cardinal veins,portal veins and their branches,or in their walls.There are abundant smooth endoplasmic reticulum and secretive granules in the super-renal tissue cells.Some secretive vesicles have electronic dense granules.The head kidney of the southern catfish is an organ of making blood,immunity and endocrine.Its super-renal tissues cells and inter-renal tissues cells are concentrate in the head kidney,which can enhance the function of endocrine and adjust the southern catfish to moving quickly and to hunt other fish for food.
A pair of degenerate primers was designed according to the reported SRY sequences about human,dog and Artiodactyla animals.Two 684 bp CDS regions of SRY gene were cloned and sequenced from male Moschus berezovskii and male M.chrysogaster genomic DNA by PCR method.Sequence analysis were conducted in the light of paternal inheritance and the SRY sequences from M.berezovskii,M.chrysogaster,and the other 18 Artiodactyla animals were used for phylogenetic tree construction by using neighbor-joining (NJ) analysis of MEGA2.1 and maximum parsimony method (MP) analysis of PAUP4.0.The phylogeny showed that the musk deer formed a monophyletic group and it supported that the musk deer should be classified as an individual family Moschidae,instead of a subfamily or a genus.
Giardia lamblia was long recognized as the most primitive eukaryote,but this is challenged recently by several analyses.With PCR and sequencing techniques,lamin gene of G.lamblia was investigated in the present paper.The results showed that its genome had a gene coding a peptide sequence with distinct features of lamin.For example,its 3 end region had a sequence coding the unique motif CaaX,which attached to the inner nuclear membrane in lamins;like type B lamin genes,it had a 27 bp conserved region,which coded a conserved 9 aa fragment in α-helix rod domain.Simultaneously,there existed some differences between these features of G.lamblia and of metazoan.Our results suggest that G.lamblia has already possessed typical eukaryotic type B lamin (gene) or at least type B.like lamin (gene),the evolutionary position of G.lamblia may not be as primitive as it was considered before.
To investigate the hazards of Hydra robusta to fish fry of Coilia mystus at the earlier development stage,we designed an experiment to put a fish fry (1-7 days of age) in the cultured solution of 200 milliliter contained 1-5 polyps.Results of experimental data analyzed by two-way analysis of variance showed that:With the polyps density increased,the death rate of fish fry increased (up to died) and the average weight of fish fry was decreased significantly (P<0.01).With the age of fish fry increased,the death rate was decreased and the average weight was increased significantly (P<0.01).It is concluded that the hazards of Hydra robusta to fish fry of Coilia mystus is extremely serious,but becomes lower and lower with development of fish fry,however,it finally influences the increase in fish weight.
Identification of the larva stage of aquatic insects is one of the most important factors in biomonitoring water quality.So far,the morphological diagnostic character for many mature and early instar larvae are still lacking in China.The partial sequences of the mitochondrial COⅠ,COⅡ and tRNA gene of the adults and larvae of 4 species from Lepidostomatidae were sequenced and compared in this study.The results indicate that intraspecific divergence is <1% between the adult and larva and the interspecific divergence is 14%-24%.The study proves that the mitochondrial DNA sequence analysis is a useful tool to associate the larval and adult stages of Trichoptera,in turn;it will be valuable for health assessment of stream ecosystems.
A limitation in advancing the study of HIV-1 is the lack of a suitable small animal model system that allows for HIV-1 infection to be monitored.A mouse model of AIDS would be very useful because of it practicality and the ready availability of knowledge,reagents and immunogenetics.SCID-hu (Thy/Liv) mouse model,in which human fetal thymus and liver tissue are co-implanted into severe combined immunodeficient mice and resulting in a functional human hematopoietic organ (Thy/Liv),recapitulates the effects of HIV-1 infection in the human thymus.SCID-hu (Thy/Liv) mice are attractive and well-established small animal models for the study of HIV-1 infection in vivo.The humanized SCID mouse model would be served as valuable tools for in vivo studying pathogenesis of HIV,analysis of candidate anti-HIV drugs and vaccines prior to their clinical evaluation in human.
Human immunodeficiency virus type 1 (HIV-1) isolates are classified phenotyically into syncytium-inducing (SI) and non-syncytium-inducing (NSI) according to their capacity to induce syncytia in MT-2 cells.Strains of HIV-1 are also classified based on their co-receptor usage.Viruses using the seven-transmembrane,G-protein-coupled,chemokine receptor CCR5,CXCR4,or both are termed R5,X4,and R5X4,respectively.HIV-1 strains of SI and X4 appear to have identical biological properties such as replication rate,cell tropism,and syncytium-inducing capacity.NSI and R5 viruses also show identical biological properties.The phenotypes of HIV-1 influence and determine viral transmission,pathogenesis and disease progression.In the course of HIV-1 infection,disease progression is associated with a switch in viral phenotype from NSI to SI,and a change in co-receptor usage from CCR5 to CXCR4.The V3 domain of HIV-1 gpl20,specifically,amino acids at V3 position 11 and 25,play a dominant role in determinant of viral phenotype and co-receptor usage.V3 sequences provide important information for prediction of HIV-1 phenotype and disease progression using bioinformatics approaches.