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31.
Seeds of theHordeum patagonicum complex were collected from the field and grown in the greenhouse. The aim was to take a sample of members of the complex, and on the basis of the phenotypic similarities in some morphological and physiological characters, determine whether distinct groups exist. When cluster analyses, to generate hypotheses, and orthodox statistical procedures, for hypotheses obtained a priori, were applied to the reproductive morphology, germination and flowering patterns, onlyH. patagonicum subsp.magellanicum, out of the five recognized taxa, could be distinguished consistently. The remaining four taxa, which overlapped considerably, could be re-formed into three groups whose centroids were different but whose ranges of variation were not distinct from each other. We conclude that the highly cross-compatible members of theH. patagonicum complex, first defined as species and later redefined as subspecies are probably no more than biotypes. 相似文献
32.
Analysis of gene expression in a human cell line stably transduced with herpesvirus saimiri 下载免费PDF全文
Hall KT Giles MS Goodwin DJ Calderwood MA Carr IM Stevenson AJ Markham AF Whitehouse A 《Journal of virology》2000,74(16):7331-7337
Herpesvirus saimiri (HVS) is the prototype gamma-2 herpesvirus; it has significant homology to the human gammaherpesviruses Kaposi's sarcoma-associated virus and Epstein-Barr virus and the murine gammaherpesvirus murine herpesvirus 68. HVS causes a persistent asymptomatic infection in its natural host, the squirrel monkey. Both subgroups A and C possess the ability to immortalize common marmoset T lymphocytes to interleukin-2-independent proliferation. However, only subgroup C is capable of transforming human, rabbit, and rhesus monkey lymphocytes in vitro. In addition, HVS can stably transduce a variety of human cell lines where the virus persists as a nonintegrating circular episome. In this study, we have developed a system in which the HVS DNA is stably maintained as a nonintegrated circular episome in the human lung carcinoma cell line A549. Virus production can be reactivated using chemical inducing agents, including tetradecanoyl phorbol acetate and n-butyrate, suggesting that the infection in human A549 cells is latent. To analyze virus gene expression in these stably transduced cells, Northern blot analysis was performed using a series of probes produced from restriction fragments spanning the entire coding region of the HVS genome. This demonstrated that an adjacent set of genes containing open reading frames (ORFs) 71 to 73 are expressed in this stably transduced cell line. Moreover, these genes are transcribed as a polycistronic mRNA species produced from a common promoter upstream of ORF 73. This model may serve as a useful tool in the further analysis of the role of ORFs 71 to 73 in gamma-2 herpesvirus latency. 相似文献
33.
Lindstrom S Schumacher F Siddiq A Travis RC Campa D Berndt SI Diver WR Severi G Allen N Andriole G Bueno-de-Mesquita B Chanock SJ Crawford D Gaziano JM Giles GG Giovannucci E Guo C Haiman CA Hayes RB Halkjaer J Hunter DJ Johansson M Kaaks R Kolonel LN Navarro C Riboli E Sacerdote C Stampfer M Stram DO Thun MJ Trichopoulos D Virtamo J Weinstein SJ Yeager M Henderson B Ma J Le Marchand L Albanes D Kraft P 《PloS one》2011,6(2):e17142
Genome-wide association studies (GWAS) have identified multiple single nucleotide polymorphisms (SNPs) associated with prostate cancer risk. However, whether these associations can be consistently replicated, vary with disease aggressiveness (tumor stage and grade) and/or interact with non-genetic potential risk factors or other SNPs is unknown. We therefore genotyped 39 SNPs from regions identified by several prostate cancer GWAS in 10,501 prostate cancer cases and 10,831 controls from the NCI Breast and Prostate Cancer Cohort Consortium (BPC3). We replicated 36 out of 39 SNPs (P-values ranging from 0.01 to 10−28). Two SNPs located near KLK3 associated with PSA levels showed differential association with Gleason grade (rs2735839, P = 0.0001 and rs266849, P = 0.0004; case-only test), where the alleles associated with decreasing PSA levels were inversely associated with low-grade (as defined by Gleason grade <8) tumors but positively associated with high-grade tumors. No other SNP showed differential associations according to disease stage or grade. We observed no effect modification by SNP for association with age at diagnosis, family history of prostate cancer, diabetes, BMI, height, smoking or alcohol intake. Moreover, we found no evidence of pair-wise SNP-SNP interactions. While these SNPs represent new independent risk factors for prostate cancer, we saw little evidence for effect modification by other SNPs or by the environmental factors examined. 相似文献
34.
J. Benjamin Miller Amitesh Pratap Akira Miyahara Liang Zhou Stephen Bornemann Richard J. Morris Giles E.D. Oldroyd 《The Plant cell》2013,25(12):5053-5066
The establishment of symbiotic associations in plants requires calcium oscillations that must be decoded to invoke downstream developmental programs. In animal systems, comparable calcium oscillations are decoded by calmodulin (CaM)–dependent protein kinases, but symbiotic signaling involves a calcium/CaM–dependent protein kinase (CCaMK) that is unique to plants. CCaMK differs from the animal CaM kinases by its dual ability to bind free calcium, via calcium binding EF-hand domains on the protein, or to bind calcium complexed with CaM, via a CaM binding domain. In this study, we dissect this dual regulation of CCaMK by calcium. We find that calcium binding to the EF-hand domains promotes autophosphorylation, which negatively regulates CCaMK by stabilizing the inactive state of the protein. By contrast, calcium-dependent CaM binding overrides the effects of autophosphorylation and activates the protein. The differential calcium binding affinities of the EF-hand domains compared with those of CaM suggest that CCaMK is maintained in the inactive state at basal calcium concentrations and is activated via CaM binding during calcium oscillations. This work provides a model for decoding calcium oscillations that uses differential calcium binding affinities to create a robust molecular switch that is responsive to calcium concentrations associated with both the basal state and with oscillations. 相似文献
35.
A fungal metallothionein is required for pathogenicity of Magnaporthe grisea 总被引:1,自引:0,他引:1 下载免费PDF全文
Tucker SL Thornton CR Tasker K Jacob C Giles G Egan M Talbot NJ 《The Plant cell》2004,16(6):1575-1588
The causal agent of rice blast disease, the ascomycete fungus Magnaporthe grisea, infects rice (Oryza sativa) plants by means of specialized infection structures called appressoria, which are formed on the leaf surface and mechanically rupture the cuticle. We have identified a gene, Magnaporthe metallothionein 1 (MMT1), which is highly expressed throughout growth and development by M. grisea and encodes an unusual 22-amino acid metallothionein-like protein containing only six Cys residues. The MMT1-encoded protein shows a very high affinity for zinc and can act as a powerful antioxidant. Targeted gene disruption of MMT1 produced mutants that show accelerated hyphal growth rates and poor sporulation but had no effect on metal tolerance. Mmt1 mutants are incapable of causing plant disease because of an inability to bring about appressorium-mediated cuticle penetration. Mmt1 appears to be distributed in the inner side of the cell wall of the fungus. These findings indicate that Mmt1-like metallothioneins may play a novel role in fungal cell wall biochemistry that is required for fungal virulence. 相似文献
36.
Jon T Giles Moyses Szklo Wendy Post Michelle Petri Roger S Blumenthal Gordon Lam Allan C Gelber Robert Detrano William W Scott Jr Richard A Kronmal Joan M Bathon 《Arthritis research & therapy》2009,11(2):R36
Introduction
Although cardiovascular morbidity and mortality are increased in rheumatoid arthritis, little is known about the burden of subclinical coronary atherosclerosis in these patients.Methods
Using computed tomography, coronary artery calcification was measured in 195 men and women with rheumatoid arthritis aged 45 to 84 years without clinical cardiovascular disease and compared with 1,073 controls without rheumatoid arthritis enrolled in the Baltimore cohort of the Multi-Ethnic Study of Atherosclerosis.Results
The prevalence of coronary calcification (Agatston score > 0) was significantly higher in men, but not women, with rheumatoid arthritis after adjusting for sociodemographic and cardiovascular risk factors (prevalence ratio = 1.19; P = 0.012). Among participants with prevalent calcification, those with rheumatoid arthritis had adjusted mean Agatston scores 53 units higher than controls (P = 0.002); a difference greater for men than women (P for interaction = 0.017). In all analyses, serum IL-6 attenuated the association between rheumatoid arthritis and coronary calcification, suggesting its role as a potential mediator of enhanced atherosclerosis. Notably, increasing severity of rheumatoid arthritis was associated with a higher prevalence and extent of coronary calcification among both men and women with rheumatoid arthritis, and for all age categories. The largest percentage difference in coronary arterial calcification between rheumatoid arthritis patients and their nonrheumatoid arthritis counterparts was observed in the youngest age category.Conclusions
Increasing rheumatoid arthritis disease severity was associated with a higher prevalence and greater extent of coronary artery calcification, potentially mediated through an atherogenic effect of chronic systemic inflammation. Gender and age differences in association with coronary calcification suggest that preventive measures should be emphasized in men with rheumatoid arthritis, and considered even in younger rheumatoid arthritis patients with low levels of traditional cardiovascular risk factors. 相似文献37.
Power management is becoming very important in data centers. To apply power management in cloud computing, Green Computing has been proposed and considered. Cloud computing is one of the new promising techniques, that are appealing to many big companies. In fact, due to its dynamic structure and property in online services, cloud computing differs from current data centers in terms of power management. To better manage the power consumption of web services in cloud computing with dynamic user locations and behaviors, we propose a power budgeting design based on the logical level, using distribution trees. By setting multiple trees or forest, we can differentiate and analyze the effect of workload types and Service Level Agreements (SLAs, e.g. response time) in terms of power characteristics. Based on these, we introduce classified power capping for different services as the control reference to maximize power saving when there are mixed workloads. 相似文献
38.
The vertebrate dermal skeleton has long been interpreted to have evolved from a primitive condition exemplified by chondrichthyans. However, chondrichthyans and osteichthyans evolved from an ancestral gnathostome stem‐lineage in which the dermal skeleton was more extensively developed. To elucidate the histology and skeletal structure of the gnathostome crown‐ancestor we conducted a histological survey of the diversity of the dermal skeleton among the placoderms, a diverse clade or grade of early jawed vertebrates. The dermal skeleton of all placoderms is composed largely of a cancellar architecture of cellular dermal bone, surmounted by dermal tubercles in the most ancestral clades, including antiarchs. Acanthothoracids retain an ancestral condition for the dermal skeleton, and we record its secondary reduction in antiarchs. We also find that mechanisms for remodeling bone and facilitating different growth rates between adjoining plates are widespread throughout the placoderms. J. Morphol., 2013. © 2013 Wiley Periodicals, Inc. 相似文献
39.
Conodonts, thelodonts and acanthodians have previously been collected from the P?ídolí of Shropshire (Welsh Borderland) from bone beds such as the Ludlow Bone Bed. In general, specimens collected from these types of deposit are very abraded and make taxonomic studies difficult. This contribution describes well preserved thelodont microelements from two samples from the Downton Castle Sandstone Formation (P?ídolí, Silurian) of the Much Wenlock area of Shropshire. Head scales, a wide variety of transitional scales, and pore scales of the lateral line sensory canals of the thelodont Paralogania ludlowiensis (Gross) are described for the first time. A new acanthodian Nostolepis linleyensis sp. nov. and elements from the apparatus of the conodont Ozarkodina?hemensis sp. nov. are documented from the same samples. The thelodonts in both samples are typical of upper Ludlow–P?ídolí faunas from across the Welsh Borderland, and are also present in smaller numbers in the Ludlow Series of Gotland, Sweden, Saaremaa Island, Estonia, and in Latvia and Lithuania. The conodont O? hemensis sp. nov. is restricted to the Much Wenlock area of Shropshire. The co-occurrence of well preserved elements of conodonts and thelodonts suggests that they were deposited fairly rapidly with little or no re-working and that a restricted marine environment prevailed in the early P?ídolí in the Much Wenlock area of Shropshire. 相似文献
40.
J. D. Penschow Michelle E. Giles John P. Coghlan R. T. Fernley 《Histochemistry and cell biology》1997,107(5):417-422
Carbonic anhydrase VI (CA VI) is a secreted enzyme produced predominantly by serous acinar cells of submandibular and parotid
glands. We have investigated the developmental pattern of CA VI production by these glands in the sheep, from fetal life to
adulthood, using immunohistochemistry. Also, a specific radioimmunoassay for CA VI was used to measure changes in enzyme expression
in the parotid gland postnatally. CA VI is detectable by immunohistochemistry in parotid excretory ducts from 106 days gestation
(term is 145 days), in striated ducts from 138 days and in acinar cells from 1 day postnatal. The duct cell content of CA
VI declined as the acinar cell population increased, a feature also of CA VI immunoreactivity in the submandibular gland.
Production of CA VI by submandibular duct cells was detectable initially at 125 days gestation, and acinar production was
not seen before 29 days post-natal. Apart from the differing ontogeny of CA VI production in ducts and acini of parotid and
submandibular glands, there was a parallel pattern of CA VI expression during the development of these major salivary glands.With
the development of the acinar tissues in the postnatal lamb, there was a dramatic increase (about 600-fold) in the level of
expression of CA VI in the parotid gland between days 7 and 59 as measured by radioimmunoassay.
Accepted: 19 December 1996 相似文献