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2000年  第21卷  第1期

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研究论文
Recent progress in study on learning and memory of mutant mice was summarized in this paper.In our work the conditioned avoidance training of Fyn-deficient mice was carried out in a one way avoidance box.In order to avoid eliciting the hyperreactivity to the aversive stimulus,the minimal intensity of electric shock for driving the mouse to run to the safe compartment.The homozygous mutant mice needed much more numbers of trials (79.13±30.1) for reaching the learning criterion than heterozygous (27.38±7.86) and wild-type (34.87±10.9) mice did.These results showed that Fyn-deficiency impairs associative learning.It was supposed that to select the proper behavioral models seems very important for studying on learning and memory of mutant mice.The behavioral model of conditioned avoidance task may be useful for behavioral study of mutant mice.Moreover,as the gene expression may be different in defferent stages of development,to study the behavioral changes of transgenic mice in different stage of development will provide us more information about the functions of genes.The preliminary results of our recent study on behavior of GABA-transported gene (GAT1) transgenic mice showed that in adult mice GAT1 was expressed much more than that in young animals.
Optical imaging based on intrinsic signals is a newly emerged technique to detect the functional signals in the brain.Since it has no toxic effect and could provide a high spatial resolution it has been widely used in the functional architecture study of the visual,auditory and somatosensory cortex.In this paper,we introduced the recent progress on the vision research using this technique,and compared it with other brain functional imaging technique and single unit recording.We established the first optical imaging system in China.Using this system,the orientation map has been successfully recorded in the primary visual cortex in the cat at different depths,By now,a lot of work has been done with the system recently.
Interaction between growth and reproduction occurs in many vetebrates.The endocrine factors which regulate growth and metabolism are also affected on puberty and gonadal development.Similarly,the hormones which effect on reproduction are also influ enced on growth and metabolism.Recent studies on fish revealed the neuroendocrine interactions between the gonadotropic axis and the somatotropic axis.For example,gonadotropin-releasing hormone (GnRH) and dopamine could stimulate the release of growth hormone,sex steroid could modulate growth hormone secretion;also,growth hormone could accelerate gonadal development and maturation.Some new findings from studies on fish have not yet been obtained in mammals and other vertebrates are remains to be further investigated.
Apoptosis and programmed cell death are normal processes in multicellular organisms.They are as important as proliferation for tissue development and homeostasis.Disregulation of apoptosis and programmed cell death would not only result in disturbance of tissue development and homeostasis,but would also cause a serial pathological changes.The aim of this review is to summarize the current knowledge on morphology,induction,genetic regulation and biochemical background of apoptosis and programmed cell death.
China s first generation of contraceptive vaccine has been developed through the multi-center collaboration research program supported by National Research Project during the past ten years.The basic principle of the vaccine s formulation was designed to use a key pregnant-depentent,transit present,tissue specific and molecular structure well-known glycoprotein hormone—human chorionic gonadotropic hormone through the application of protein engineering techniques,the crossreactivity with three other pituitary glycoprotein hormones and the immunotolerance of the body to this "self" hormone have been overcome and the biological activity of hCG remained intact.Pre-clinical nonhuman primate toxicology & safety study has been carried out in Guangdong Primate Center successfully.Two principal investigators of this research project have received the pilot inoculation of China s first generation of contraceptive vaccine to obtain the direct experience of immune response,ten volunteers of tubular ligated female have entered into the first phase clinical pilot trial in 1995 and successfully proved that China s first generation of hCG controceptive vaccine is immunogenic,safe,no toxic reactions in human beings. The formulation of second generation of a new vaccine to enhance the immunogenecity through protein and genetic engineering is now in progress.
Whether panda belongs to Ursidae,Procyonidae or an independent family had been debated until the 1980s,when O Brien and others posed a series of researches on the protein and DNA of the giant panda.Until the 1990s,most of the western scholars agreed that panda belonged to Ursidae while most of the Chinese scholars insisted that it should be an independent family,considering every factor of biology and researches on the molecular level as well as on palaeontology.QIU Zhan-xiang et al.studied the fossils of pandas ancestors found in Yunnan Province in 1989.HUANG Wan-bo studied pandas skulls,mandibles and teeth in 1993.All these studies have further proved that it was in the later Miocene period that the Ailurarctos and Ursavus began to develop parallelly:the former had developed to panda while the latter had developed to bear (all the species in Ursidae). The studies on population ecology of panda during the latest years are summarized overall in five aspects.The first is population.With different methods,we believe that there is 200 or so in Qingling mountains,300 or so in Mingshan and Qionglai mountains,less than 40 in Daxiangling and Xiaoxiangling mountains,more than 100 in Liangshan mountains,the total is 1000 or so.The second is population characteristic.The third is population growth and fluctuation.The fourth is genetic diversity.The genetic diversity from high to low in different mountains is:Qionglaishan→Mingshan→Qingling→Liangshan→Xiaoxiangling→Daxiangling.There is distinct genetic differentiation in different mountains,especially in polymorphic aspect of genetic group.There are three different genetic groups:the populations in Qingling mountains,Mingshan-Qionglai mountains and Liangshan mountains are in kinship.There are close kinship between the populations in Mingshan-Qionglai mountains and Liangshan mountains,but their kinship with Qingling mountains is quite far.The fifth is viability analysis.At the same time,some problems existed among them are brought up and discussed.
The genetic polymorphism in populations of the Chinese shrimp,Penaeus chinensis,along the coast of China was examined with mitochondrial DNA analysis.A portion of the 16S ribosomal RNA (16S rRNA) genes from 17 individuals,five from each of samples caught off Changdao,Yantai,Qingdao,and also for two individuals from a cultured stock sampled from Ningbo was amplified with the polymerase chain reaction (PCR) and sequenced.Out of 523 nucleotide sites,37 nucleotide positions (7.07%) were variable and 17 haplotypes were found.Molecular phylogenetic tree constructed by UPGMA method suggested that there were some genetic differential among different geographic populations of Chinese shrimp.Changdao population and Yantai population had a closer genetic relationship.The second was Ningbo population.Qingdao populations diverged to be as one relatively independent branch.
The cDNA encoding a variant of α-bungarotoxin was cloned from the venom glands of Bungarus multicinctus by RT-PCR.The deduced protein precursor contained a 21 amino acid signal peptide and a following 74 amino acid mature protein.The signal peptide is very similar to those of short chain neurotoxins,κ-neurotoxins and cardiotoxins.The amino acid sequence of the mature protein is identical to α-bungarotoxin (V31),a minor variant of α-bungarotoxin identified by protein sequencing technique.Furthermore,the cDNA encoding the deletion precursor of α-bungarotoxin was also cloned.By use of pMAL-p2,the variant was overexpressed in E.coli as a soluble fusion protein and purified by sepharose 6B-amylose affinity chromatography,which was confirmed by western blotting with the antisera against α-bungarotoxin.The recombinant variant was achieved after digestion by factor X[a].It displayed about 1/6 in vivo toxicity of natural α-bungarotoxin.The successful cloning and functional expression of α-bungarotoxin provided a basis for the future study of structure-function of long neurotoxins.
From June to October in 1996,the situation of giant pandas selection and utilization for one of its main foods—Fargesia nitida was studied in detail in Huanglongsi Reserve and compared with the data obtained from other mountains .Results show as follows:(1)We can divide one year into four periods for giant pandas selection on food,through the analysis of droppings and feeding places monthly.(a) From November of last year to June of next year.the stems of bamboo are the main food of pandas (80%),and the percentage of each age group is:old shoots∶two-year olds∶many-year olds=1∶2.33∶5.33.(b) The first and second ten days of July are the transition period (In this period,giant panda feeds not only on the stem but also on some new shoots occasionally and the percentage of each age group is:new shoots∶old shoots∶two-year olds∶many-year olds=1∶1.8∶0.5∶0.8).? From the last ten days of July to the second ten days of September,the giant panda feeds on the new shoots (>75%) and some stems occasionally.(d)From the last ten days of September to October,the giant panda feeds on the leaves and branches as well as a small number of stems.(2)Bamboo plots was set up and Vanderploeg and Scavia selectivity index was used to assess the pandas selection for Faresia nitida,we also compared it with other mountains .The results show that for a long time,the giant panda in different mountains adapts the different species of bamboo,which bring about the difference in their feeding habits.However,there is a general tendency that they always prefer the thick stems and thick shoots,which obey the economic principle.(3)The giant panda in Huanglong prefer the stems (basal diameter>10 mm) and the shoots (basal diameter>10 mm),but refuse to eat the slim stems (basal diameter<4 mm) and the shoots (basal diameter<6 mm).(4)The comparison sample height method was used to study the using rate of bamboo stems eaten by giant panda,the result is 22.825%.
Greater Brown Wren Warbler (Prinia subflava) and yellow-bellied Wren Warbler (P.flaviventris) are the sympatric species pair in south China.In this paper,the interspecific niche relationship between the two bird species was studied.The authors intended to determine if there is a interspecific competition by means of regression analysis of niche breadth,niche overlaps and complex population density.The results indicated that there was a competition between the two species of Wren Warbler.They did not discrease their niche breadth to avoid competition.On the contrary,they increase their niche breadth respectively to reduce the proportion of overlap so that competition pressure could be discreased.These conditions are favorable to the coexistence.
From 1994 to 1998,observations on the breeding habits and growth of the nestling of black-crowned heron were made in the Changshan and Yuhang Bird Reserve,Zhejiang Province.The results were as following:1)The adults migrated to this reserve in the middle and late April and lefted in the late September.2)Average height of nests from grownd was 8.51 m and the nests were simple,dash-shapped with following measurements:external diameter 30-50 cm,internal diameter 20-30 cm,depth 3.5-8.0 cm.3.)The average number of egg of 35 clutches was 3.49,the incubation period 22-26 days,the survival rate in incubation period 95.45%,the length of nursing period about 30-35 days.4)The body weight of the nesting was 26.8 g at the 1st day of hatching,and increases to a maximun of 556 g at the 51 th day.The growth of weight in 51 days after birth was fitted by the following model:W[t]=560/1+e[-0.231(t-12)] with R[2]=0.99.The length-weight relationship could be expres sed in the following formula:W=0.000246 L[2.5029].5)The process of establishment of homeothermal ability involved 3 periods:(I)the confused growth period (1-16 day);(ii)the growth period (17-28 day);(iii)the homeothermal period (after 28 day).6)The main food of nestlings is Cambaroides (45%),Cyprinidae (40%),Cobitaidae (15%).
During Aug.-Oct.1994 and Nov-Dec.1995,the studies on the fragmentation of habitats used by Elliots pheasant were done in Shuiwu,Xiaobeilong and Yancun of Kaihua County,western Zhejiang with field observation and measurement.The index of the fragmentation (F) and its formula were produced in this paper.The fragmentation of the habitats,used by Elliots pheasant was measured with this index.The results showed that the habitat fragmentation and loss would cause the loss of habitats used by Elliots pheasant.
This paper deals with the composition of ant communities and species diversity.Trap and sample plot were used in the investigation in the fragments of seasonal rain forest of different size and environmental status.The ants collected in the 4 spots belong to 4 subfamilies,24 genera and 50 species.The number of species in Chengzi Holly Hill was the highest.Dominant species in these spots were different.The common species were fewer and only 4 species appear in all the spots.The similarity of ant communities between plots was low and the coefficient was 0.1622-0.3548.A dendrogram constructed by the Jaccard index showed that similarity between Chengzi and Botanical Garden Reserve was the highest (0.3548).Species diversity indexes (H) of ants in the Chengzi Holly Hill,the Manyangguang Holly Hill,the Botanical Garden Reserve and the Nature Reserve were 1.7771,1.6521,2.3785,0.9612 respectively.
Laizhou Bay (37°10′-38°20′N,118°30′-120°30′E) is not only an important spawning site and habitat for fishery resources in the Yellow Sea and the Bohai Sea,but also a traditional fishing site.The results from pair-trawl surveys in different seasons in the area indicate that fishs abundance,diversity and dominance have changed dramatically.The mean catches per haul are 258,117,77.5 and 8.5 kg/h in 1959,1982,1992-1993 and 1998,respectively.The largesized demersal fish,such as largehead hairtail (Trichiurus haumela) and small yellow croaker (Pseudosciaena polyactis) have been replaced by halffin anchovy (Setipinna taty),anchovy (Engraulis japonicus) etc.since the 1980s.The community structure of fishery resources has apparently varied.The continuous releasing penaeid shrimp (Penaeus chinensis) in large-scale has caused the decrease of genetic heterozygosity in the wild stock.The corresponding protection measures to inhabiting environment and biodiversity are suggested based on the analyses of variation of main fishery resources.
44 Enhydris chinensis (29 females,14 males,1 focus) got in the market were used in the examination of the middle cross-sections of vertebrae ground in an ordinary abrasive disc way (taking five vertebraes near the heart).Under a microscope their annual rings were observed.We can see that the older the snakes are,the clearer their rings are.Correctness of the resorbed growth layers in the process of the skeleton growth by the regression equation of vertebrae radius vs growthlayer width and von Bertalanffy growth equation indicates that the ages of the Enhydric chinensis specimens range from 0-11.2 years,their ages and their body length form a ringe relationship,the regression equation of the females is L (total length)=272.4+647.2l g A (year),r=0.9598,P<0.01;that of the males being L=317.5+46.3 A (year),r=0.9527,P<0.01,and the earliest sexual maturity of the females appears at the age of 1.8 years,that of the males at 1.0 year.