Genetic analysis established that Aitaiyin3, a dwarf rice variety derived from a semidwarf cultivar Taiyin1, carries two recessive semidwarf genes. By using simple sequence repeat (SSR) markers, we mapped the two semidwarf genes, sd-1 and sd-t2 on chromosomes 1 and 4, respectively. Sd-t2 was thus named because the semidrawf gene sd-t has already been identified from Aitaiyin 2 whose origin could be traced back to Taiyin1. The result of the molecular mapping of sd-1 gene revealed it is linked to four SSR markers found on chromosome 1. These markers are: RM297, RM302, RM212, and OSR3 spaced at 4.7 cM, 0 cM, 0.8cM and 0 cM, respectively. Sd-t2 was found to be located on chromosome 4 using five SSR markers: two markers, SSR332 and RM1305 located proximal to sd-t2 are spaced 11.6 cM, 3.8 cM, respectively, while the three distally located primers, RM5633, RM307, and RM401 are separated by distances of 0.4 cM, 0.0 cM, and 0.4 cM, respectively.

Human placental ribonuclease inhibitor (hRI) is an acidic protein of Mr?50kDa with unusually high contents of leucine and cysteine residues. It is a cytosolic protein that protects cells from the adventitious invasion of pancreatic-type ribonuclease. hRI has 32 cysteine residues, and the oxidative formation of disulfide bonds from those cysteine residues is a rapid cooperative process that inactivates hRI. The most proximal cysteine residues in native hRI are two pairs that are adjacent in sequence. In the present aork, two molecules of alanine substituting for Cys328 and Cys329 were performed by site-directed mutagenesis. The site-mutated RI cDNA was constructed into plasmid pPIC9K and then transformed Pichia pastoris GS115 by electroporation. After colony screening, the bacterium was cultured and the product was purified with affinity chromatography. The affinity of the recombinant human RI with double site mutation was examined for RNase A and its anti-oxidative effect. Results indicated that there were not many changes in the affinity for RNase A detected when compared with the wild type of RI. But the capacity of anti-oxidative effect increased by 7~9 times. The enhancement in anti-oxidative effect might be attributed to preventing the formation of disulfide bond between Cys328 and Cys329 and the three dimensional structure of RI was thereby maintained.

A recombinant strain of Salmonella choleraesuis C500, containing a eukaryotic expression plasmid pBO1 with the immune-dominant epitope of foot-and-mouth disease virus, was constructed. Specific immune response to this recombinant strain was evaluated by oral administration of the recombinant live bacteria pBO1/S. cho in rabbits. Results showed that T cell response and specific antibody production were elicited. This approach may present a general strategy for eliciting immune responses with DNA vaccine delivered by live bacterial vectors. The stimulated indexes of T lymphoproliferation by specific antigens of FMDV in rabbits, can reach up to 11.0 and an antibody titer of 1/32 as detected in the erum with liquid block ELISA.

Yeast two-hybrid approach is popularly used nowadays as an important technical method in the field of studying protein-protein interactions. Although yeast two-hybrid system is obviously advantageous in searching interacting proteins and setting up the network of proteins interaction, not all of proteins can use routine yeast two-hybrid method to search interacting proteins. Many important proteins, such as some nucleoprotein transcriptional factor, carry out the regular method and construct the bait-BD vector to screen the library containing AD vector. However, it usually results in failures because it contains the activate domain and can self-activate the reporter gene. In this study, we changed the research strategy, fused the bait gene (FOXA3) with the AD vector to screen the library containing BD vector, so that we constructed a two-hybrid library containing BD vector and can bypass the interference of self-activation. And we used this two-hybrid library to screen FOXA3, a hepatocyte nuclear factor, and found out an interacting protein: complement component C3.

Malondialdehyde (MDA) is a well known inducer of carbonyl stress in a variety of human cells, however, its effects on human bone marrow mesenchymal stem cells (hMSCs) have not been documented. In this study, the effects of MDA concentration on the growth rate and proliferation of hMSCs in vitro were assessed. Under high concentrations of MDA, the cell count was decreased and the population doubling time (PDT) was lengthened. Flow cytometry (FCM) demonstrated that MDA triggered cells to undergo apoptosis, in parallel with the findings in MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay which showed that it can also impair cellular viability. Surprisingly, FCM also determined that the percentage of hMSCs in G₂/M- and S- phases also increased in a dose-dependent manner with respect to MDA concentration. These results strongly suggest that even though hMSCs were severely impaired by high concentrations of MDA, they were still able to send signals that resulted in accelerated cellular proliferation process. This study provided important insights on how carbonyl stress affects cell cycle and proliferation of hMSCs.

The effects of hematopoietic stem/progenitor cells (HSPCs) expanded in the two step coculture with human bone marrow mesenchymal stem cells (hMSCs) on the hematopoietic reconstruction of irradiated NOD/SCID mice were studied. Mononuclear cells (MNCs) were isolated from human umbilical cord blood (UCB) and cultured in the non-coculture scheme of rhSCF + rhG-CSF + rhMDGF combination and the coculture scheme of rhSCF + rhG-CSF + rhMDGF + hMSCs. Sublethally-irradiated NOD/SCID mice were transplanted with ex vivo expanded HSPCs with the dose of 8.5 ? 10⁶ cells per mouse. After transplantation, the dynamics of WBC in the transplanted mice was measured periodically, and the Alu sequence fragment special for human in the transplanted mice was inspected by PCR. Results showed that the coculture scheme increased proliferation of UCB-derived HSPCs. After transplantation with expanded HSPCs, the population of WBC in the transplanted mice increased in 12 d and reached the first peak in 25 d, then showed the second increasing of WBC in 45~55 d. Expanded cells from the coculture scheme appeared to be favorable for the second increasing of WBC in the transplanted mice. After 85 d, the Alu sequence fragment was detected in the probability of 87.5% (7/8) for the non-coculture scheme and 88.9% (8/9) for the coculture scheme.

Soil animals are abundant in forest litter layer, but little attention has been paid to the vertical distribution of community structure of soil animals in the layers at different plant community succession stages. The forest litter layer can be divided into fresh litter layer (L), fermentation layer (F) and humus layer (H), which may represent different litter decomposition stages. The aim of the study is to ascertain the vertical distribution features of soil animal communities among the three litter layers and the change in the succession process of the Evergreen Broad-Leaved Forest (EBLF) in Tiantong, Zhejiang Province, China. Soil animal communities in the five plant communities at different succession stages were investigated during the 2003 winter. Soil animals, which were collected by using Tullgren funnels, amounted to a total of 13 381 individuals falling into 2 phyla, 8 classes and 20 orders. The dominant groups were Acarina and Collembola, accounting for 94.24% of the total individuals, with the number of Acarina individuals 7.66 times than that of Collembola. The common group was Diptera. The results indicated that there was a distinctive vertical distribution of the soil animal communities in the forest litter layer, but it differed from that in soil below the litter layer. In contrast to those in the soil, the soil animals in the litter layer generally tended to increase in both group abundance and density from the top fresh litter layer to the bottom humus layer. Altogether 19 groups and 59.03% of total individuals were found in the bottom layer, while only 8 groups and 5.35% of the total individuals in the top. Moreover, there were some variations in the distribution of the soil animals at different plant succession stages. 85.19% of Homoptera and 100% of Symphyla were found in the litter layer at the climax succession stage, while 75.61% of Thysanoptera at the intermediate succession stage. Therefore, these groups might be seen as indicative groups. The total numbers of soil animal groups and individuals in the litter layers greatly changed in the succession process of the EBLF. They both were greatest at the climax, moderate at the intermediate and smallest at the primary succession stage. However, the main soil animal groups in the litter at the different succession stages were essentially the same. They were Acarina, Collembola, Diptera and Lepidoptera. Although similarity analysis revealed that the soil animal communities in the litter at the intermediate succession stage were most similar to those at the climax succession stage, they differed greatly from each other in the Shannon-Wiener diversity index. The Shannon-Wiener index was highest at the climax succession stage and lowest at the intermediate succession stage. Finally, the paper discusses the following three questions: the role of soil animals as indicators for plant community succession; the role of different soil animal groups in the litter decomposition at different stages; and the major factors affecting the composition and distribution of soil animals in the litter. This paper provides a new perspective for the research on the succession mechanism of plant communities and the decomposition functions of soil animals.

The genetic diversity within and among populations of Hepatacodium miconioides collected at three different altitudes in Tiantai Mountain, Zhejiang Province and its relationships to environmental factors were analyzed by random amplified polymorphic DNA (RAPD) technique. Amplification using 12 random primers of 60 plants and 122 repetitive loci were produced. The percentage of polymorphic loci of three populations ranged from 18.85% to 23.77% with an average of 21.86%, indicating the relatively low genetic diversity of H. miconioides. The average Shannon index of phenotypic diversity (0.1329) and Nei index (0.0925) within populations were relatively low. A distinct genetic differentiation existed among populations of H. miconioides in spite of the relatively small geographical distribution. The average genetic diversity within populations of H. miconioides accounted for 33.58% of the total genetic diversity while the genetic diversity among populations accounted for 66.42% as estimated by the Shannon index of phenotypic diversity, The genetic differentiation among populations of H. miconioides was 0.6546, as estimated by Nei index. The gene flow estimated from G_ST was only 0.2656 and it indicated that gene flow among populations of H. miconioides was relatively low. The mean value of the genetic identity among populations of H. miconioides was 0.7126 and the average of genetic distance of H. miconioides was 0.3412. The genetic identity between populations at the elevation of 990 m and at the elevation of 780 m was the highest. The genetic identity between population at the elevation 500 m and other two populations was relatively low. The correlation analysis showed that the genetic diversity within populations was significantly related with the soil total nitrogen.

Mountain Yunmeng (37?20 2N?113?54 2E ) is 1 520m above sea level and part of the Taihang Mountains. With a temperate continental monsoon climate, the mountain area belongs to the warm temperate deciduous broad-leaved forest region. This thesis was mostly based on the study of more than 2 000 packages of bryophytes which were mainly collected by the authors in Mt.Yunmeng, Hebei Province. Of these specimens, there are 36 families, 99 genera, and 244 species (including 17 varieties, 5 formes, and 1 subspecies) which have been studied and identified. Moreover, it could be seen that Mt.Yunmeng has a diverse population of bryophytes. The bryoflora could be divided into 10 geographical elements: north temperate element make up the majority, accounting for 52.11% of the entire known bryoflora, and another belongs to the East Asian element, accounting for 19.25%. All temperate elements, not including 14 endemic to China and 31 Cosmopolitans, were added up to 188 species, which took 88.3% of all the entire known bryoflora in Mt.Yunmeng. However, there were only 11 Subtropical and Tropical elements. To all appearances, the bryoflora of Mt.Yunmeng showed obvious temperate characteristics. The authors conclude that the bryoflora in Mt.Yunmeng belongs to the middle type, between the warm and dry northern mountain area and the warm and damp southern mountain area. The microclimatic environment greatly influences the bryoflora.

The communities of Larix chinensis and their ecotone in Qinling Mountains were investigated by sampling belt method. Species richness, Simpson diversity, Shannon-Weiner diversity, PIE and Pielou evenness indices of vascular plants in their communities and ecotone were calculated. Structure and composition of the communities in 6 sampling belts within the sites were analyzed. The results showed that the edge effect was obvious in the ecotone with a less changing environment (such as soil and terrain) and acute variation of composition and structure, while inconspicuous or even none in the ecotone with worse environmental condition (such as great space fluctuation). It is apparent that the edge effect of community was affected by soil and terrain, but not by microclimate.

Endophyte-infected (EI) seeds of Lolium perenne L. were used to attain endophyte-free (EF) population by heating the seeds at 43! for 15 min and then 57! for 25 min. Relative water content (RWC), chlorophyll, soluble sugar and starch content of EI and EF populations under normal and drought stress conditions were compared to investigate the effect of endophyte infection on the host plant. Under severe stress, RWC of EI leaf was significantly higher than that of EF leaf, i.e. EI plants took more advantages over EF plants in water-holding ability. Under mild stress, endophyte could enhance soluble sugars in host plants to improve their osmotic ability. With stress intensification, the improvement of endophyte no longer existed, and more photosynthetic products (such as starch) accumulated in EI plants to survive through the undesirable conditions. In the next spring, EI populations will recover more rapidly than EF populations. The biomass of a population is closely related to its photosynthesis. Under severe stress, EI population significantly accumulated more biomass than EF population. As far as photosynthetic pigments were concerned, contents of Chla, Chlb and Car of EI plants were close to those of EF plants, which suggested that endophyte infection didn t alleviate photosynthetic pigments from being destroyed by drought stress, and endophyte might improve photosynthesis ability of its host plant in other ways.

Home range and habitat use of male Reeves s pheasant (Syrmaticus reevesii) were studied during winter of 2001~2002 and 2002~2003 in the Dongzhai National Nature Reserve, Henan Province. Results from five individuals of Reeves s pheasant with over 30 relocations, indicated that the average size of home range was 10.03 ? 1.17 hm² by Minimum Convex Polygon method, 8.60 ? 0.35 hm² by 90% Harmonic Mean Transformation method, and 9.50 ?1.90 hm² by 95% Fixed Kernel method. It was observed that the winter range is smaller than that in the breeding season. The mean core area of the home range was found to be 1.88 ? 0.37 hm². Although the habitat composition of the core area varied greatly for individuals, a large part of the habitats used were composed of conifer and broadleaf mixed forests, masson pine forests, fir forests, and shrubs. Habitat use within the study area was non-random, while habitats within home ranges were randomly used. Habitat use was dictated by tree diameter at breast height, shrub height and coverage at 2.0 m. The proximity between forests and shrubs were also found to be important in providing refuge for the birds during winter. Recommendations for conservation management include protecting the existing habitats in Dongzhai National Nature Reserve, increasing suitable habitat for Reeves s Pheasant through artificial plantations (e.g. firs), and restoring some parts of the large shrub area into forests.

The dynamics of tree layer biomass was studied by combining 35 sample plots of field census with biomass model estimation in a natural Quercus aliena var. acutesrata community on Mountain Xiaolong in Gansu Province, China. The tree layer biomass of Quercus aliena var. acutesrata community was 183 660 kg/ha, in which the slow growth group accounted for 64.89% of the total biomass. The fast-medium growth group accounted for 33.40% and the coniferous group accounted for 1.38%. The organs biomass was found to be in the following order: trunk > root > branch > leaf. The total biomass accumulated with the development of the community. The total biomass and the biomass of the organs were highest in the mature community and became stable as the community developed. The relative growth rate of organs was in the following order: trunk > branch > root > leaf. The biomass ratio of the slow growth group trees tended to increase and the fast-medium group trees tended to decrease as the community developed, which was reveresed in the decline development stage. The biomass of the coniferous group was very small throughout the development process.

The vegetation pattern in the upstream of Minjiang River, and its relationship with environment factors, such as landscape position (elevation, slope, aspect), precipitation and temperature and soil are analyzed in this paper. The data used in this paper were based on the landscape map derived from 1994 TM imagery. The results were as follows: 1) dominant landscape types were forest, shrub land and grassland, which were very similar in terms of area ratio (32.87%, 31.85% and 28.44%, respectively); 2) the patch shape of conifer forest and mixed forest was complicated while that of broad-leaved forest and cultivated land was simple; 3) the fragmentation of conifer forest and mixed forest was serious in contrast with low fragmentation of broad-leaved forest and cultivated land; and 4) closed scrub and grassland had a high contagion and good connectivity while mixed forest had a lower contagion and bad connectivity. In addition, the vegetation distribution pattern of upstream of Minjiang River was closely related with elevation and temperature, but the relationship between vegetation and precipitation was not statistically significant.

A cellular automata model to simulate penicillin fed-batch fermentation process (CAPFM) was established in this study, based on a morphologically structured dynamic penicillin production model, that is in turn based on the growth mechanism of penicillin producing microorganisms and the characteristics of penicillin fed-batch fermentation. CAPFM uses the three-dimensional cellular automata as a growth space, and a Moore-type neighborhood as the cellular neighborhood. The transition rules of CAPFM are designed based on mechanical and structural kinetic models of penicillin batch-fed fermentation processes. Every cell of CAPFM represents a single or specific number of penicillin producing microorganisms, and has various state. The simulation experimental results show that CAPFM replicates the evolutionary behavior of penicillin batch-fed fermentation processes described by the structured penicillin production kinetic model accordingly.

Here we report a new method to detect DNA point mutations. The method is based on the formation and deformation of double-stranded DNA (dsDNA) membranes on a gold surface. It can encage reporter molecules between the gold surface and the double-stranded DNA or keep them away from the gold surface. In these systems, Fe(CN)₆^3- was used as the reporter. As the temperature increases, a sharp electrochemical signal change in the melting curve of wild-type dsDNA appears. At a special temperature, the method gives 100:1 selectivity for the perfect complement and single base mutation target. Thus, the system provides a simple and sensitive method to detect DNA point mutations without labeling targets.

The apoptosis of cells is one of the fields that attract increasing attention in biology today. Usually, the cells are treated with chemicals when detecting apoptosis. It is highly desired to detect apoptosis in a real-time basis. Apoptosis of Jurkat cells was studied using a real-time electrorotation chip. This chip allows the detection of the cell membrane capacitance changes during the course of apoptosis and therefore facilitates the analysis of apoptosis in a real-time basis without involving any chemical treatment.

Recent collections from six sections in Lanongla area, Tethyan Himalaya allow the establishment of four buchia assemblages. In ascending order, they are Buchia-Buchia spitiensis, Buchia masquensis-Buchia rugasa, Buchia blanfordiana, Buchia piochii and Buchia subokensis assemblages. These Buchia assemblages first demonstrate that not only the Upper Jurassic strata but also the highest Buchia assemblage-Buchia subokensis, which appeared in Lower Cretaceous strata all over the world are present in Lanongla area. This first records the highest Buchia assemblage in Lanongla area.