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Ultracytochemical localization of Ca2+ during the phloem ganglion development in Phyllostachys edulis
YU Fen, DING Yulong
Front. Biol.. 2006, 1 (3): 219-224.
https://doi.org/10.1007/s11515-006-0026-7
Ultracytochemical localization of Ca2+ was investigated using the potassium pyroantimonate precipitation method during the development of phloem ganglion. The result showed that Ca2+ was mainly localized in the cell wall and intercellular spaces in the initiating phase. With the development of the phloem ganglion, the distribution of Ca2+ transferred to the vacuole, and the Ca2+ deposits in the cell wall and intercellular space decreased. At the later stage of the developmental phase, Ca2+ was distributed in the tonoplast and vacuole phagocytosis, and the vacuole became the main calcium storage in this phase. At the early stage of maturation of the phloem ganglion, most of the phloem ganglion cells vacuoles cracked, and the cytoplastic Ca2+ content increased in large number. In the mature phloem ganglion, not only were there a few Ca2+ localized in the cytoplast of mature cells, but also in the differentiating cells in the vacuoles. Ca2+ was distributed in the tonoplast and vacuole contents; initiating cells almost had no Ca2+. In general, Ca2+ concentration in mature phloem ganglion cells was at a low level. The results indicated that the changes in Ca2+ distribution evoked the phloem ganglion generation, and Ca2+ regulated the physiological function of the phloem ganglion.
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Cytokines mRNA in bone marrow-derived dendritic cells in asthmatic mouse
YU Duowei, WU Jianqing, YUAN Sheng, SUN Yun
Front. Biol.. 2006, 1 (3): 241-245.
https://doi.org/10.1007/s11515-006-0029-4
By inducing and amplifying dendritic cells (DCs) derived from the bone marrow of asthma murine in vitro, cytokines mRNA were expressed, and the functions of DCs were investigated. Cells isolated from murine bone marrow have been cultured with rmGM-CSF and rmIL-4, and the expression of cytokines mRNA was determined by ribonuclease protection assay combined with multi-probe templates. Large numbers of DCs have been obtained from bone marrow, and they expressed interleukin-13 (IL-13), interleukin-9 (IL-9), and interleukin-3 (IL-3) mRNA. Moreover, the level of IL-13 mRNA and IL-9 mRNA expressed by DCs in asthmatic mice was significantly higher than those in the control groups (P<0.05). But, the level of IL-3 mRNA showed no discrepancy between the two groups (P>0.05). DCs are very important in the forming and developing of asthma, which implies that the therapy targeted at DCs will possibly become a new goal.
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Purification and properties of alkaline phosphatase of silkworm Bombyx mori
TANG Yunming, CEN Liang, LI Changchun, XU Min, LUO Ying, LU Cheng
Front. Biol.. 2006, 1 (3): 246-253.
https://doi.org/10.1007/s11515-006-0030-y
Alkaline phosphatase (AKP), from the succus entericus of silkworm, was purified using 10% 50% ammonium sulfate fractions, ion exchange chromatography of DEAE-Sepharose, and size exclusion chromatography of Sephacryl S-200. The purification fold was 464 times and specified activity was 3 936 U/mg. Optimum pH value of the phosphatase was 10.5, and was stable between pH 7.5 and 11. The optimum temperature of the phosphatase was 40?C and it was unstable over 50?C. Km value of the phosphatase was 1.25 mmol/L. In a given condition, the phosphatase was selectively modified by PCMB, NBS, PMSF, TNBS, SUAN, DTT, BrAc, and IAc, the results indicate that PMSF, SUA, BrAc, IAc, and TNBS could obviously inhibit the activity of the phosphatase, and the degree of inhibition depended on the concentration of these reagents. There was little effect on the activity of phosphatase after treatment by PMSF, DTT, and NBT. We primarily conclude that mercapto and imidazole are essential for AKP from silkworm. Also, Lys residue and disulfide bands are necessary to protect the catalysis of the AKP.
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Isolation and cultivation of murine hematopoietic stem cells and expression of hFIX mediated by recombinant lentiviral vectors in vitro
YAO Hengmei, CHEN Haoming, HUANG Lu, SHEN Qi, JIA Weiguo, XUE Jinglun
Front. Biol.. 2006, 1 (3): 259-262.
https://doi.org/10.1007/s11515-006-0016-9
Hematopoietic stem cells (HSCs) are an attractive target for gene therapy, especially for inherited blood diseases. Moreover, recombinant lentiviral vectors are considered to be prospective in HSCs gene therapy for the high efficiency of infection. In this study, murine mononuclear cells (MNCs) were isolated from bone marrow and cultured in suspension, and then Lin-CD117+ HSCs were isolated by immunomagnetic beads. During culturing, cells and colonies increased in HSCs supplied with cytokines while no change was observed in the control group without cytokines. FUXW recombinant lentiviral vectors were produced by calcium phosphate-mediated transient cotransfection infected MNCs from ICR and C57 mice. The hFIX expressions were 41.7 ± 4.2 ng / mL and 34.5 ± 6.6 ng/mL in supernatant on 7d. The hFIX expressions of HSCs infected by FUXW recombinant lentiviral vectors were 46.6 ± 5.7 ng/mL (with cytokines) and 33.3 ± 4.8 ng/mL (without cytokines) in supernatant on 7d. Results indicate that recombinant lentiviral vectors can infect murine MNCs and Lin-CD117+ HSCs efficiently, and expression of the transgene can be improved when supplied with cytokines.
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Postglacial population expansion of Dacrydium pectinatum (Podocarpaceae) in Hainan, southern China, based on cpDNA trnL-F nocoding sequence data
SU Yingjuan, SUN Yufei, JIANG Yu, DENG Feng, WANG Bosun, WANG Ting, CHEN Guopei
Front. Biol.. 2006, 1 (3): 263-269.
https://doi.org/10.1007/s11515-006-0032-9
This study determined the sequences of chloroplast DNA (cpDNA) trnL-F non-coding regions of individuals of a tropical coniferous species, Dacrydium pectinatum, collected from 12 natural populations located in Hainan Province, southern China. Sequence length varied from 868 bp to 876 bp, indicating length polymorphism. Base composition in the sequences was high in A+T content between 64.17% and 64.95%, and no recombination event occurred (Rm = 0). Thirty haplotypes were identified based on statistical parsimony algorithm by running the TCS program. Populations of D. pectinatum in Hainan were lacking genetic differentiation. Such a deduction was supported by the observed FST values (0.00), AMOVA (24.17% of molecular variance attributed to difference among populations, P>0.05), high values of Nm (ranging from 1.92 to 2.50) and the branching structure in neighbor-joining (NJ) tree constructed from haplotypes. A star-like pattern was exhibited in the TCS network of trnL-F haplotypes, and majority of the haplotypes coalesced near the tips in NJ tree. Gene genealogies of cpDNA haplotypes proposed a recent population expansion of D. pectinatum in Hainan, which was further supported by the results from Tajima s D test and mismatch distribution analysis. Our data, in conjunction with geological and palynological evidences, showed that in the Holocene, due to global warming, refugee populations of D. pectinatum in Hainan might experience a range expansion.
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A comparison of in vitro anticancerous activity and mechanism of ethanolic extracts from different Ganoderma genus
ZHOU Yueqin, LI Xuquan, FENG Huiqin, MI Ke, YANG Qingyao, YANG Xiaotong
Front. Biol.. 2006, 1 (3): 275-279.
https://doi.org/10.1007/s11515-006-0034-7
Five ethanolic extracts from the mycelia of Ganoderma lucidum, G. tsugae, G. oerstedii, G. subamboinense, and G. resinaceum were respectively studied on their anticancerous activities against leukemic HL-60 cell
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Karyotype analysis and physical mapping of 45S rDNA in eight species of Sophora, Robinia, and Amorpha
LIU Bo, CHEN Chengbin, LI Xiulan, QI Liwang, HAN Suying
Front. Biol.. 2006, 1 (3): 290-294.
https://doi.org/10.1007/s11515-006-0036-5
The karyotype analysis and physical locations of 45S rDNA were carried out by means of fluorescence in situ hybridization in three species, and two forms of Sophora, two species of Robina, and one specie
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Seasonal dynamics of fine root biomass, root length density, specific root length, and soil resource availability in a Larix gmelinii plantation
CHENG Yunhuan, WANG Qingcheng, WANG Zhengquan, HAN Youzhi
Front. Biol.. 2006, 1 (3): 310-317.
https://doi.org/10.1007/s11515-006-0039-2
Fine root turnover is a major pathway for carbon and nutrient cycling in terrestrial ecosystems and is most likely sensitive to many global change factors. Despite the importance of fine root turnover in plant C allocation and nutrient cycling dynamics and the tremendous research efforts in the past, our understanding of it remains limited. This is because the dynamics processes associated with soil resources availability are still poorly understood. Soil moisture, temperature, and available nitrogen are the most important soil characteristics that impact fine root growth and mortality at both the individual root branch and at the ecosystem level. In temperate forest ecosystems, seasonal changes of soil resource availability will alter the pattern of carbon allocation to belowground. Therefore, fine root biomass, root length density (RLD) and specific root length (SRL) vary during the growing season. Studying seasonal changes of fine root biomass, RLD, and SRL associated with soil resource availability will help us understand the mechanistic controls of carbon to fine root longevity and turnover. The objective of this study was to understand whether seasonal variations of fine root biomass, RLD and SRL were associated with soil resource availability, such as moisture, temperature, and nitrogen, and to understand how these soil components impact fine root dynamics in Larix gmelinii plantation. We used a soil coring method to obtain fine root samples ("d2 mm in diameter) every month from May to October in 2002 from a 17-year-old L. gmelinii plantation in Maoershan Experiment Station, Northeast Forestry University, China. Seventy-two soil cores (inside diameter 60 mm; depth intervals: 0 10 cm, 10 20 cm, 20 30 cm) were sampled randomly from three replicates 25 m?30 m plots to estimate fine root biomass (live and dead), and calculate RLD and SRL. Soil moisture, temperature, and nitrogen (ammonia and nitrates) at three depth intervals were also analyzed in these plots. Results showed that the average standing fine root biomass (live and dead) was 189.1 g "m-2 "a-1, 50% (95.4 g "m-2 "a-1) in the surface soil layer (0 10 cm), 33% (61.5 g "m-2 "a-1), 17% 32.2 g "m-2 "a-1) in the middle (10 20 cm) and deep layer 20 30cm), respectively. Live and dead fine root biomass was the highest from May to July and in September, but lower in August and October. The live fine root biomass decreased and dead biomass increased during the growing season. Mean RLD (7,411.56 m "m-3 "a-1) and SRL (10.83 m "g-1 "a-1) in the surface layer were higher than RLD 1 474.68 m "m-3 "a-1) and SRL (8.56 m "g-1 "a-1) in the deep soil layer. RLD and SRL in May were the highest 10 621.45 m "m-3 and 14.83m "g-1) compared with those in the other months, and RLD was the lowest in September 2 198.20 m "m-3) and SRL in October (3.77 m "g-1). Seasonal dynamics of fine root biomass, RLD, and SRL showed a close relationship with changes in soil moisture, temperature, and nitrogen availability. To a lesser extent, the temperature could be determined by regression analysis. Fine roots in the upper soil layer have a function of absorbing moisture and nutrients, while the main function of deeper soil may be moisture uptake rather than nutrient acquisition. Therefore, carbon allocation to roots in the upper soil layer and deeper soil layer was different. Multiple regression analysis showed that variation in soil resource availability could explain 71 73% of the seasonal variation of RLD and SRL and 58% of the variation in fine root biomass. These results suggested a greater metabolic activity of fine roots living in soil with higher resource availability, which resulted in an increased allocation of carbohydrate to these roots, but a lower allocation of carbohydrate to those in soil with lower resource availability.
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Fruits foraging patterns and seed dispersal effect of frugivorous birds on Hippophae rhamnoides sinensis
LU Xianwen, SUN Kun, MA Ruijun, ZHANG Hui, SU Xue, WANG Mingli
Front. Biol.. 2006, 1 (3): 318-322.
https://doi.org/10.1007/s11515-006-0040-9
Behaviors of 18 species of birds eating fruits of Hippophae rhamnoides spp. sinensis were observed from September 2003 to March 2004. Their foraging patterns were found to be very different and can be divided into five classes: (1) direct swallowing the fruits on crown of the shrubs and sometimes regurgitating seeds soon after; (2) carrying the fruits to their perching sites and swallowing; (3) pecking the fruits from the shrubs to the ground, eating pulp and seeds but leaving pericarp; (4) pecking through the pericarp, eating pulp and leaving pericarp and seeds; (5) pecking through the pericarp on the top of fruits, and only eating seeds. These foraging patterns have different effects on seed dispersal of H. rhamnoides spp. sinensis. The germination experiment of three groups of seeds (seeds from feces, dry fruits and extracted seeds from dry fruits) was carried out. Although ingestion processes of birds had some adverse effects on the seed germination of H. rhamnoides spp. sinensis, the seeds from feces still have a relatively higher germination ratio. H. rhamnoides spp. sinensis provides food to a variety of frugivorous birds, and the birds disperse its seeds. Thus, a mutually beneficial relationship between the bird and the seed is formed.
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Ecosystem health assessment on the hill and gully area of Loess Plateau in lnner Mongolia, China
HUANG Heping, YANG Jie, SONG Bingyu, BAO Tiejun
Front. Biol.. 2006, 1 (3): 323-331.
https://doi.org/10.1007/s11515-006-0041-8
Maintenance of ecosystem health is the primary focus of a sound ecological restoration. Yet methods involved in quantifying and assessing the health level remain a challenge to the ecological community. In this study, we selected the hill and gully area of Loess Plateau, Inner Mongolia, China, as our study area. The soil and water erosions in this area continue to be responsible for many environmental problems in northern China because of its fragility and long disturbance history. In this study, we developed an assessment method of indicator system (AMIS) based on analytical hierarchy process (AHP), fuzzy mathematics, and the theory of net-hierarchy. At ecosystem or catchment scale, three sample areas, that is (1) intact vegetation (i.e., Aguimiao Natural Reserve, 110º45 2E, 39º28 2N), (2) reconstructed vegetation (Wufendigou Soil and Water Conservation Experimental Area, 111º07 2E, 39º45 2N), and (3) severely degraded vegetation (Yangquangou Catchment, 111º06 2E, 39º45 2N) in the hill and gully area of Loess Plateau in Inner Mongolia, China, were selected to examine ecosystem vigor, organizational structure, service function, and soil health. We applied the AMIS for all three landscapes by categorizing each ecosystem into five health levels. We found that the health index for reconstructed vegetation were at levels of IV, II, IV, and III, while those of degraded vegetation were ranked at V, IV, V, and IV. Overall, the comprehensive ecosystem health index of reconstructed vegetation was lower than that of intact vegetation but higher than that of degraded vegetation. The health index for reconstructed vegetation was at level III, and that of degraded vegetation was still at level IV. The contributing values were: organization structure > soil health > vigor > service function. Based on our results and assessments, we proposed several management recommendations and methods for restoring the regional ecosystems.
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Early Silurian (Telychian) rugose coral fauna of Daguan area, northeast Yunnan Province, China
CHEN Jianqiang, HE Xinyi, TANG Lan
Front. Biol.. 2006, 1 (3): 332-344.
https://doi.org/10.1007/s11515-006-0042-7
Study on rugose coral fauna of the Sifengya Formation (early Telychian) and Daluzhai Formation (mid-late Telychian) in Daguan area, northeast Yunnan Province, China was carried out. Rugose coral fauna of the Sifengya Formation included 18 genera and 34 species, while Daluzhai Formation with nine genera, ten species. We described rugose coral fauna (12 genera, 19 species) including one new genus and five new species, i.e. Protoketophyllum daguanense gen. et sp. nov., Crassilasma huanggexiense sp. nov., Pseudophaulactis heae sp. nov., P. convolutus sp. nov., and Shensiphyllum minor sp. nov.. The characteristics and geological significance of rugose coral fauna of Sifengya Formation and Daluzhai Formation were analyzed. Particularly, rugose coral fauna of the Sifengya Formation represent early Telychian rugosan fauna in the Upper Yangtze region and improve the sequences of early Silurian (Llandovery) rugose coral assemblages in Yangtze region. It is therefore very meaningful to further analyze radiation period of rugose coral fauna in such epoch.
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