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951.
Alexandra Průchová Oldřich Nedvěd Petr Veselý Bára Ernestová Roman Fuchs 《Entomologia Experimentalis et Applicata》2014,151(2):128-134
Previous studies have suggested that spotted patterns are important in the protection of ladybirds against attack by avian predators. Nevertheless, these studies were based on the comparison of several ladybird species differing in colouration, but also in other traits (e.g., chemical protection). We presented natural as well as artificial colour modifications (using brown, red, and black paint) of the ladybird Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) – an invasive alien species for Europe – to an avian predator, the great tit, Parus major L. (Passeriformes: Paridae). All forms were considered to be equal in size, but differed in colouration and in the presence of spots. The chemical protection was equal except for one form. The birds displayed strong avoidance of all forms with red and black colouration; beetles with artificially removed red colouration (painted brown) were attacked more often. The beetles painted brown with black spots were slightly better protected than the painted beetles without spots. We can sum up that spots are of some importance in the protection of ladybirds; nevertheless, red and black colouration is the main part of the visual signal. 相似文献
952.
Jiří Friml 《European journal of cell biology》2010,89(2-3):231-235
The directional transport of the plant hormone auxin is a unique process mediating a wide variety of developmental processes. Auxin movement between cells depends on AUX1/LAX, PGP and PIN protein families that mediate auxin transport across the plasma membrane. The directionality of auxin flow within tissues is largely determined by polar, subcellular localization of PIN auxin efflux carriers. PIN proteins undergo rapid subcellular dynamics that is important for the process of auxin transport and its directionality. Furthermore, various environmental and endogenous signals can modulate trafficking and polarity of PIN proteins and by this mechanism change auxin distribution. Thus, the subcellular dynamics of auxin transport proteins represents an important interface between cellular processes and development of the whole plant. This review summarizes our recent contributions to the field of PIN trafficking and auxin transport regulation. 相似文献
953.
Zheng-ke Zhan Kun-mei Ji Xiao-yu Liu Zhi-gang Liu Meng Li Jia-jie Chen Jia-na Li Shi Qiu 《Experimental & applied acarology》2010,52(1):63-71
Home dust mite derived materials are known to be a major source of problematic inhalant allergens. The aim of this study was
to determine the localization of the group 3 allergen, Der f 3, within Dermatophagoides farinae, in order to assess the relative importance of excreted materials and nonexcreted body components as allergen sources. Recombinant
Der f 3 (rDer f 3) was expressed in bacteria and purified as an immunogen for production of monoclonal antibodies (mAb) against
it. Dermatophagoides farinae mites and their faecal pellets were embedded in paraffin, and serial sections were immunoprobed with mAb clone 3D3 against
Der f 3. D. farinae midgut mucosa, gut contents and faecal pellets were strongly immunopositive for Der f 3. Der f 3 immunoreactive products
were not detected in any other internal organs of the mite. These results suggest that Der f 3 allergen may be synthesized
in and secreted from the digestive tract and excreted from the mite’s body in the faecal pellets. 相似文献
954.
Development of a stepwise aeration control strategy for efficient docosahexaenoic acid production by Schizochytrium sp. 总被引:1,自引:0,他引:1
Lu-Jing Ren Xiao-Jun Ji He Huang Liang Qu Yun Feng Qian-Qian Tong Ping-Kai Ouyang 《Applied microbiology and biotechnology》2010,87(5):1649-1656
The effect of aeration on the performance of docosahexaenoic acid (DHA) production by Schizochytrium sp. was investigated in a 1,500-L bioreactor using fed-batch fermentation. Six parameters, including specific growth rate,
specific glucose consumption rate, specific lipid accumulation rate, cell yield coefficient, lipid yield coefficient, and
DHA yield coefficient, were used to understand the relationship between aeration and the fermentation characteristics. Based
on the information obtained from the parameters, a stepwise aeration control strategy was proposed. The aeration rate was
controlled at 0.4 volume of air per volume of liquid per minute (vvm) for the first 24 h, then shifted to 0.6 vvm until 96 h,
and then switched back to 0.4 vvm until the end of the fermentation. High cell density (71 g/L), high lipid content (35.75 g/L),
and high DHA percentage (48.95%) were achieved by using this strategy, and DHA productivity reached 119 mg/L h, which was
11.21% over the best results obtained by constant aeration rate. 相似文献
955.
夏季舟山渔场及邻近海域浮游动物群落结构特征分析 总被引:5,自引:0,他引:5
2006年8月在舟山渔场及邻近海域(29°30′ ~31°30′ N,124°30′ E以西)开展海洋生态系统综合调查,用浅水Ⅰ型浮游生物网采集的浮游动物样本,对该海域浮游动物的种类组成、数量分布、生物多样性等群落结构特征进行了分析。结果得知,在调查海域共鉴定出浮游动物93种(不包含浮游幼虫),其中以桡足类的种类数为最多,有50种,优势种主要有精致真刺水蚤(Euchaeta concinna)、软拟海樽(Dolioletta gegenbauri)、肥胖箭虫(Sagitta enflata)、百陶箭虫(Sagitta bedoti)、中华哲水蚤(Calanus sinicus)、普通波水蚤(Undinula vulgaris)、微刺哲水蚤(Canthocalanus paupe)、长尾类幼虫(Macruran larvae)、双生水母(Diphyes chamissonis)、背针胸刺水蚤(Centropages dorsispinatus)、肥胖三角溞(Evadne tergestina)、太平洋纺锤水蚤(Acartia pacifica)等12种。调查海域浮游动物丰度平面分布呈现南部高、北部低,近岸高、外海低的特征。生物多样性分析表明,调查海域浮游动物种类数较多,且具有较高的均匀度(0.70),因此其生物多样性指数较高(4.98)。根据聚类分析结果,可将夏季调查海域的浮游动物在17.13%相似性水平上分为A、B、C三个组群。生物8722;环境匹配分析显示,浮游动物的丰度除了与表层盐度、硝酸氮和硅酸盐含量有关外,还与镉、铅的含量存在着一定相关性。 相似文献
956.
The Mre11/Rad50/Nbs1 (MRN) complex has a central function in facilitating activation of the ATM protein kinase at sites of DNA double‐strand breaks (DSBs). However, several other factors are also required in human cells for efficient signalling through MRN and ATM, including the tumour suppressor proteins p53‐binding protein 1 (53BP1) and BRCA1. In this study, we investigate the functions of these mediator proteins in ATM activation and find that the presence of 53BP1 and BRCA1 can amplify the effects of MRN when interactions between MRN and ATM are compromised. This effect is dependent on a direct interaction between MRN and the tandem breast cancer carboxy‐terminal (BRCT) repeats in 53BP1, and is accompanied by hyper‐phosphorylation of both Nbs1 and 53BP1. We also find that the BRCT domains of 53BP1 affect the overall structure of 53BP1 multimers and that this structure is important for promoting ATM phosphorylation of substrates as well as for the repair of DNA DSBs in mammalian cells. 相似文献
957.
Xiaoyun Ji Geoff Sutton Gwyndaf Evans Danny Axford Robin Owen David I Stuart 《The EMBO journal》2010,29(2):505-514
Natural protein crystals (polyhedra) armour certain viruses, allowing them to survive for years under hostile conditions. We have determined the structure of polyhedra of the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV), revealing a highly symmetrical covalently cross‐braced robust lattice, the subunits of which possess a flexible adaptor enabling this supra‐molecular assembly to specifically entrap massive baculoviruses. Inter‐subunit chemical switches modulate the controlled release of virus particles in the unusual high pH environment of the target insect's gut. Surprisingly, the polyhedrin subunits are more similar to picornavirus coat proteins than to the polyhedrin of cytoplasmic polyhedrosis virus (CPV). It is, therefore, remarkable that both AcMNPV and CPV polyhedra possess identical crystal lattices and crystal symmetry. This crystalline arrangement must be particularly well suited to the functional requirements of the polyhedra and has been either preserved or re‐selected during evolution. The use of flexible adaptors to generate a powerful system for packaging irregular particles is characteristic of the AcMNPV polyhedrin and may provide a vehicle to sequester a wide range of objects such as biological nano‐particles. 相似文献
958.
Wenyan Liu Ji Wang Qiuling Li Zhihua Ju Jinming Huang Hongmei Wang Shunde Liu Jianbin Li Jifeng Zhong Changfa Wang 《Molecular biology reports》2010,37(8):3771-3777
As an essential signaling modulator, Src gene appears to be necessary for increased expression of the prolactin receptor, normal downstream signaling, and alveolar cell organization. In this study, we detected the polymorphism of Src gene by polymerase chain reaction-restriction fragment length polymorphism assay (PCR-RFLP) and DNA sequencing methods in 985 individuals from three Chinese cattle breeds. Three novel single nucleotide polymorphisms (SNPs) (g.14062C>T ss161151834, g.17302G>A ss161151835, g.18107T>C ss161151836) were detected. Least squares analysis showed that cows with g.14062C>T-CC genotypes and g.18107T>C-TT genotypes had the highest protein rate, while the cows with g.17302G>A-GG genotype had higher 305 d milk yield (p < 0.05), fat yield (p < 0.01) and protein yield (p < 0.01) than the ones with genotypes g.17302G>A-GA. These results revealed the statistical significant effects of three SNPs of the Src gene on the milk production traits in Chinese Holstein. In addition, based on the nine genotypes constructed from 27 combined haplotypes, the association analysis between combined haplotypes and milk production traits was carried out. Statistic results showed that the cows with combined haplotypes H2H4(CCGATT) had the highest fat rate and the highest protein rate and the cows with combined haplotypes H1H8(TCGATC) and H3H7(TCGGCC) had greater 305 d mild yield than H1H2(CCAATC)(P < 0.05). Our finding demonstrated that the Src gene possibly contributed to conducting association analysis and can be recognized as genetic marker in milk production traits and other performance for animal breeding and genetics. 相似文献
959.
John Yeuk-Hon Chan Li Li Ji Miao Dong-Qing Cai Kenneth Ka-Ho Lee Yiu-Loon Chui 《Molecular biology reports》2010,37(1):363-368
Stress-responsive genes play critical roles in many biological functions that includes apoptosis, survival, differentiation
and regeneration. We have identified a novel stress-responsive gene called BRE which interacts with TNF-receptor-1 and blocks the apoptotic effect of TNF-α. BRE enhances tumor growth in vivo and is up-regulated in hepatocellular and esophageal carcinomas. BRE also regulates the ubiquitination of the DNA repair complex BRCC, and the synthesis of steroid hormones. Here, we examined
BRE-mRNA in cells after treatments with UV and ionizing radiation (IR). UV and IR treatment alone suppressed BRE-mRNA levels by more than 90% at 24 h, while hydroxyurea, fluorodeoxyuridine, aphidicolin, known inhibitors of S-phase DNA
synthesis, had no significant effect. BRE protein expression was unaltered in cells treated with TNF-α, Interleukin-1 and Dexamethasone, while a threefold increase
was observed following chorionic gonadotropin exposure. Although BRE plays a regulatory role in many different pathways, yet its expression is apparently under very stringent control. 相似文献
960.
Martina Kyselková Jiří Janata Markéta Ságová-Marečková Jan Kopecký 《Archives of microbiology》2010,192(3):195-200
In acetohydroxy acid synthase from Streptomyces cinnamonensis mutants affected in valine regulation, the impact of mutations on interactions between the catalytic and the regulatory subunits
was examined using yeast two-hybrid system. Mutations in the catalytic and the regulatory subunits were projected into homology
models of the respective proteins. Two changes in the catalytic subunit, E139A (α domain) and ΔQ217 (β domain), both located
on the surface of the catalytic subunit dimer, lowered the interaction with the regulatory subunit. Three consecutive changes
in the N-terminal part of the regulatory subunit were examined. Changes G16D and V17D in a loop and adjacent α-helix of ACT
domain affected the interaction considerably, indicating that this region might be in contact with the catalytic subunit during
allosteric regulation. In contrast, the adjacent mutation L18F did not influence the interaction at all. Thus, L18 might participate
in valine binding or conformational change transfer within the regulatory subunits. Shortening of the regulatory subunit to
107 residues reduced the interaction essentially, suggesting that the C-terminal part of the regulatory subunit is also important
for the catalytic subunit binding. 相似文献