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101.
A library of monoclonal antibodies specific for myosin heavy chain (HC) was used to study myosin expression in regenerating fibers. The response to cold injury of slow skeletal ALD muscle previously induced to eliminate SM1 myosin by weight overload was compared to that of its contralateral control. Native gel electrophoresis combined with immunoblotting demonstrated that slow SM1 myosin HC eliminated from hypertrophic muscle reappeared both at the site of active regeneration and unexpectedly, also distal to the site of injury. The regeneration response of hypertrophied muscles was similar to that of the controls. In addition to SM1 myosin HC, ventricular-like and embryonic/fast isoforms were also expressed in both muscles during the early stages of regeneration and disappeared as the muscle fibers matured. These observations demonstrate that regenerating slow muscle fibers reexpress myosins' characteristic of developing muscle irrespective of the myosin phenotype prior to injury. The reappearance of repressed myosin HC in the hypertrophied ALD muscle is consistent with the presence of newly differentiated myonuclei. 相似文献
102.
103.
Xiujuan Li Laura Gualandi Sina Koch Malin Jarvius Ola Söderberg Andrey Anisimov Bronislaw Pytowski Megan Baldwin Seppo Ylä‐Herttuala Kari Alitalo Johan Kreuger Lena Claesson‐Welsh 《The EMBO journal》2010,29(8):1377-1388
The vascular endothelial growth factors VEGFA and VEGFC are crucial regulators of vascular development. They exert their effects by dimerization and activation of the cognate receptors VEGFR2 and VEGFR3. Here, we have used in situ proximity ligation to detect receptor complexes in intact endothelial cells. We show that both VEGFA and VEGFC potently induce formation of VEGFR2/‐3 heterodimers. Receptor heterodimers were found in both developing blood vessels and immature lymphatic structures in embryoid bodies. We present evidence that heterodimers frequently localize to tip cell filopodia. Interestingly, in the presence of VEGFC, heterodimers were enriched in the leading tip cells as compared with trailing stalk cells of growing sprouts. Neutralization of VEGFR3 to prevent heterodimer formation in response to VEGFA decreased the extent of angiogenic sprouting. We conclude that VEGFR2/‐3 heterodimers on angiogenic sprouts induced by VEGFA or VEGFC may serve to positively regulate angiogenic sprouting. 相似文献
104.
CD46 is a cellular receptor for human herpesvirus 6 总被引:29,自引:0,他引:29
Human herpesvirus 6 (HHV-6) is the etiologic agent of exanthema subitum, causes opportunistic infections in immunocompromised patients, and has been implicated in multiple sclerosis and in the progression of AIDS. Here, we show that the two major HHV-6 subgroups (A and B) use human CD46 as a cellular receptor. Downregulation of surface CD46 was documented during the course of HHV-6 infection. Both acute infection and cell fusion mediated by HHV-6 were specifically inhibited by a monoclonal antibody to CD46; fusion was also blocked by soluble CD46. Nonhuman cells that were resistant to HHV-6 fusion and entry became susceptible upon expression of recombinant human CD46. The use of a ubiquitous immunoregulatory receptor opens novel perspectives for understanding the tropism and pathogenicity of HHV-6. 相似文献
105.
人蛔虫和猪蛔虫同域种群DNA多态性研究 总被引:1,自引:0,他引:1
在我国蛔虫感染遍布各地,受染人数达5亿多.而在多数农村流行区,生猪饲养十分普遍,人群和猪群的蛔虫感染往往并存,且人、猪接触密切.据作者在江西省新建县蔓湖村进行的一年纵向调查,当地人群蛔虫感染率和猪群蛔虫感染率比较接近(约60%-70%),土壤蛔虫卵污染普遍而严重,并长年稳定 ( Peng, W.D. et al. 1996 Ascaris, people and pigs in rural Jiangxi, China. Parasitology 113:547~557.). 因此这些地区人蛔虫和猪蛔虫交叉感染的机会是大量存在的. 相似文献
106.
Metagenomic approaches to exploit the biotechnological potential of the microbial consortia of marine sponges 总被引:1,自引:0,他引:1
Natural products isolated from sponges are an important source of new biologically active compounds. However, the development
of these compounds into drugs has been held back by the difficulties in achieving a sustainable supply of these often-complex
molecules for pre-clinical and clinical development. Increasing evidence implicates microbial symbionts as the source of many
of these biologically active compounds, but the vast majority of the sponge microbial community remain uncultured. Metagenomics
offers a biotechnological solution to this supply problem. Metagenomes of sponge microbial communities have been shown to
contain genes and gene clusters typical for the biosynthesis of biologically active natural products. Heterologous expression
approaches have also led to the isolation of secondary metabolism gene clusters from uncultured microbial symbionts of marine
invertebrates and from soil metagenomic libraries. Combining a metagenomic approach with heterologous expression holds much
promise for the sustainable exploitation of the chemical diversity present in the sponge microbial community. 相似文献
107.
Pleiotropic quantitative trait loci contribute to population divergence in traits associated with life-history variation in Mimulus guttatus 下载免费PDF全文
Evolutionary biologists seek to understand the genetic basis for multivariate phenotypic divergence. We constructed an F2 mapping population (N = 539) between two distinct populations of Mimulus guttatus. We measured 20 floral, vegetative, and life-history characters on parents and F1 and F2 hybrids in a common garden experiment. We employed multitrait composite interval mapping to determine the number, effect, and degree of pleiotropy in quantitative trait loci (QTL) affecting divergence in floral, vegetative, and life-history characters. We detected 16 QTL affecting floral traits; 7 affecting vegetative traits; and 5 affecting selected floral, vegetative, and life-history traits. Floral and vegetative traits are clearly polygenic. We detected a few major QTL, with all remaining QTL of small effect. Most detected QTL are pleiotropic, implying that the evolutionary shift between these annual and perennial populations is constrained. We also compared the genetic architecture controlling floral trait divergence both within (our intraspecific study) and between species, on the basis of a previously published analysis of M. guttatus and M. nasutus. Eleven of our 16 floral QTL map to approximately the same location in the interspecific map based on shared, collinear markers, implying that there may be a shared genetic basis for floral divergence within and among species of Mimulus. 相似文献
108.
Chloroplast DNA variation and population structure in the widespread forest tree, Eucalyptus grandis
Megan E. Jones Mervyn Shepherd Robert J. Henry Angela Delves 《Conservation Genetics》2006,7(5):691-703
Recognition of genetic structure of populations and the ability to identify vulnerable populations is useful for the formation of conservation management strategies for plants. Eucalyptus grandis is a tall forest tree that has a major area of occurrence in subtropical eastern Australia, with smaller populations located in the east coast tropics. Many widespread forest species exhibit population differentiation that corresponds to geographic regions. However, Eucalyptus grandis appears to be an exception based on isozyme and morphological data. This is intriguing given a large discontinuity between northern populations and those in the southern part of the species range. In this study, the distribution of a maternally inherited chloroplast locus was examined because it was more likely to reveal genetic structure due to the slower evolution of the chloroplast genome and limited dispersal of seed in eucalypts. As expected, the G
ST for chloroplast DNA was higher than that for nuclear DNA but indicated low population differentiation for a forest tree species. Phylogeographic analysis indicated that the 15 populations grouped into three broad geographical regions; however, overall population structure was weak suggesting that the large geographical disjunction in the distribution of E. grandis may be relatively recent. A paradigm for conservation management of E. grandis based on chloroplast DNA haplotype distribution would take into account the low differentiation among populations. 相似文献
109.
Established populations of Pseudodacrylogyrus anguillae are reported from eels in England for the first time. Prevalence and abundance peak in late summer in all three localities and the parasite overwinters at low levels on eels. 相似文献
110.
G. Senthilraja T. Anand C. Durairaj J.S. Kennedy S. Suresh T. Raguchander 《Biocontrol Science and Technology》2010,20(5):449-464
The virulence of 20 isolates of Beauveria bassiana (Balsamo) Vuillemin to larvae of the leafminer, Aproaerema modicella, was tested in the laboratory. Leafminer larvae were sprayed with a standard concentration of 1×108 condia/mL of each B. bassiana isolate. All the B. bassiana isolates tested were pathogenic to A. modicella and the mortality varied between 16.7 and 68.9%. Beauveria bassiana isolate B2 was found to be the most virulent followed by isolate B4 which resulted in 59% mortality. Beauveria isolate B2 was selected for dose–response mortality studies with four different doses (1×102, 1×104, 1×106 and 1×108 conidia/mL). Among the various doses tested, 1×108 conidia/mL produced the highest mortality (70.7%). In addition, morphogenesis of the insect pest in all stages, larval, pupal and adult was greatly affected due to fungal infection. Further, B. bassiana isolate B2 and two Pseudomonas fluorescens strains, TDK1 and Pf1 were tested alone and in combination for suppression of groundnut leafminer and collar rot disease and promotion of plant growth and yield both under glasshouse and field conditions. The mixture of B. bassiana and P. fluorescens strains significantly reduced the leafminer and collar rot disease incidences when applied as talc-based formulation through seed, soil and foliar application under glasshouse and field conditions. 相似文献