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A comparison of constitutive promoters for expression of transgenes in alfalfa (Medicago sativa).

The activity of constitutive promoters was compared in transgenic alfalfa plants using two marker genes. Three promoters, the 35S promoter from cauliflower mosaic virus (CaMV), the cassava vein mosaic virus (CsVMV) promoter, and the sugarcane bacilliform badnavirus (ScBV) promoter were each fused to the beta-glucuronidase (gusA) gene. The highest GUS enzyme activity was obtained using the CsVMV promoter and all alfalfa cells assayed by in situ staining had high levels of enzyme activity. The 35S promoter was expressed in leaves, roots, and stems at moderate levels, but the promoter was not active in stem pith cells, root cortical cells, or in the symbiotic zones of nodules. The ScBV promoter was active primarily in vascular tissues throughout the plant. In leaves, GUS activity driven by the CsVMV promoter was approximately 24-fold greater than the activity from the 35S promoter and 38-fold greater than the activity from the ScBV promoter. Five promoters, the double 35S promoter, figwort mosaic virus (FMV) promoter, CsVMV promoter, ScBV promoter, and alfalfa small subunit Rubisco (RbcS) promoter were used to control expression of a cDNA from Trichoderma atroviride encoding an endochitinase (ech42). Highest chitinase activity in leaves, roots, and root nodules was obtained in plants containing the CsVMV:ech42 transgene. Plants expressing the endochitinase were challenged with Phoma medicaginis var. medicaginis, the causal agent of spring black stem and leaf spot of alfalfa. Although endochitinase activity in leaves of transgenic plants was 50- to 2650-fold greater than activity in control plants, none of the transgenic plants showed a consistent increase in disease resistance compared to controls. The high constitutive levels of both GUS and endochitinase activity obtained demonstrate that the CsVMV promoter is useful for high-level transgene expression in alfalfa.

Badnavirus↗

Activation of the prolactin promoter in transfected GH3 cells by posterior pituitary cells.

UNLABELLED: We previously reported that PRL production is significantly enhanced by a PRL-releasing/regulating factor derived from the posterior pituitary (PP). Specifically, the levels of PRL messenger RNA synthesis and release were dramatically increased in cocultures of GH3 and PP cells. The present objectives were to: 1) determine whether PP cells activate PRL gene transcription in a promoter- and cell-specific manner; 2) compare promoter activation by PP cells with that caused by selected substances that regulate the PRL gene; and 3) examine which region of the promoter (proximal and/or distal) mediates the action of the PP. In Exp 1, GH3 cells, transfected either with luciferase reporter plasmids containing a wild type PRL promoter, a GH promoter, or a glycoprotein alpha-subunit promoter, were cocultured with PP cells. Luciferase activity was used as an index for promoter activation. PP cells induced an 18-fold stimulation of the PRL promoter, as compared with a 2-fold stimulation of the GH promoter and no effect on the glycoprotein alpha-subunit promoter. In Exp 2, GH3 cells transfected with the wild type PRL promoter were cocultured with PP, anterior pituitary, uterine, or PC12 cells for 24 h. PP cells caused a 20-fold stimulation of the PRL promoter, whereas anterior pituitary cells showed a moderate 5-fold stimulation; uterine and PC12 cells caused minimal (< 2-fold) increases in luciferase activity. In Exp 3, GH3 cells were transfected with either the wild type PRL promoter (-2500 PRLluc) or with a truncated promoter (-425PRLluc) containing the proximal region only and were incubated with PP cells, TRH, vasoactive intestinal peptide (VIP), epidermal growth factor (EGF), or estradiol (E2) for 24 h. Compared with the induction of the wild type promoter, PP cells activated the truncated promoter by 30% only. Stimulation of the promoter by relatively high concentrations of TRH, VIP, EGF, or E2, either alone or in combination, was significantly less effective than that caused by PP cells. CONCLUSIONS: 1) PP cells stimulate PRL gene transcription in a tissue- and promoter-specific manner; 2) the magnitude of induction caused by PP cells far exceeds that caused by high concentrations of TRH, VIP, EGF, or E2; and 3) the distal enhancer region of the rat PRL gene is necessary for maximal responsiveness of the PRL promoter to PP cells.

Animals↗

The extent and nature of food promotion directed to children in Australian supermarkets.

The aim of this study was to describe the nature and amount of sales promotion use on food packaging in selected Australian supermarkets, specifically those directed at children through the use of premium offers, such as giveaways and competitions, and cartoon and movie character promotions. The study also examined the promotion of healthy versus unhealthy foods. Nine supermarkets located across the metropolitan area of Sydney, Australia were surveyed to assess the extent and nature of food promotion directed at children. The number and types of promotions were measured within seven food categories: sweet biscuits, snack foods, confectionery, chips/savoury snacks, cereals, dairy snacks and ice cream. Any foods that utilized promotional tactics were categorized as either healthy or unhealthy, according to set criteria. The study found that within the seven food categories between 9 and 35% of food products used promotional tactics. The use of television, movie celebrities and cartoon characters for promotion was most common, making up 75% of all promotions. Giveaways accounted for 13% of all promotions. When used, giveaways were commonly used in conjunction with another promotional method. Data from this study also confirmed that 82% of all food promotions were for unhealthy foods and only 18% were used to promote healthy foods. However, for dairy snacks and ice cream the majority of promotions, 99 and 65%, respectively, were healthier choices. This was the first study to describe the extent and nature of food promotions used in supermarkets. The promotion of unhealthy foods in supermarkets is common and is one of the many factors contributing to today's obesity promoting environment. Further research is required to determine the impact of food promotions on children's dietary intake, and to determine the most effective ways to restrict the promotion of unhealthy foods.

Cartoons as Topic↗

Quantitative assessment of poxvirus promoters in fowlpox and vaccinia virus recombinants.

A comparison was undertaken of poxvirus promoters in vaccinia and fowlpox virus (FPV) recombinants using the level of beta-galactosidase expressed from the LacZ gene as a measure of promoter function. In this study a comparison was made of the vaccinia virus promoters, P 7.5 and P L11, the major late promoter of cowpox virus, P CPX (expressing the abundant inclusion body protein), and the FPV promoters, P E/L and P L. In vaccinia virus recombinants the FPV P E/L promoter expressed one-third to one-half the level of beta-galactosidase expressed by the P L11 promoter. In comparison with the P 7.5 promoter, the FPV P E/L promoter expressed four to five times the level of beta-galactosidase. In FPV recombinants beta-galactosidase activity expressed was equal for the P E/L and P CPX promoters. Levels expressed by P L11 and P L were one-half and one-fifth that level, respectively. The temporal regulation of the promoters was maintained in both vaccinia virus and FPV recombinants. The P E/L promoter of FPV has the TAAATG sequence characteristic of late poxvirus promoters at the transcription initiation site. In an attempt to enhance the utility of this promoter for the expression of foreign genes in FPV and vaccinia virus recombinants, the effect upon promoter function of changing the G of the ATG to A, T, or C was determined using transient expression assays with vaccinia virus. Substitution of A, T, or C for the G abolished promoter function. Because of its early/late function, the level of expression and the presence of the oppositely oriented late P L promoter, the FPV P E/L promoter will be valuable for the expression of foreign genes in poxvirus recombinants.

Base Sequence↗

The human CYP19 (aromatase P450) gene: update on physiologic roles and genomic organization of promoters.

The human CYP19 (P450arom) gene is located in the chromosome 15q21.2 region and is comprised of a 30 kb coding region and a 93 kb regulatory region. The Internet-based Human Genome Project data enabled us to elucidate its complex organization. The unusually large regulatory region contains 10 tissue-specific promoters that are alternatively used in various cell types. Each promoter is regulated by a distinct set of regulatory sequences in DNA and transcription factors that bind to these specific sequences. In most mammals, P450arom expression is under the control of gonad- and brain-specific promoters. In the human, however, there are at least eight additional promoters that seemed to have been recruited throughout the evolution possibly via alterations in DNA. One of the key mechanisms that permit the recruitment of such a large number of promoters seems to be the extremely promiscuous nature of the common splice acceptor site, since activation of each promoter gives rise splicing of an untranslated first exon onto this common junction immediately upstream of the translation start site in the coding region. These partially tissue-specific promoters are used in the gonads, bone, brain, vascular tissue, adipose tissue, skin, fetal liver and placenta for physiologic estrogen biosynthesis. The most recently characterized promoter (I.7) was cloned by analyzing P450arom mRNA in breast cancer tissue. This TATA-less promoter accounts for the transcription of 29-54% of P450arom mRNAs in breast cancer tissues and contains endothelial-type cis-acting elements that interact with endothelial-type transcription factors, e.g. GATA-2. We hypothesize that this promoter may upregulate aromatase expression in vascular endothelial cells. The in vivo cellular distribution and physiologic roles of promoter I.7 in healthy tissues, however, are not known. The gonads use the proximally located promoter II. The normal breast adipose tissue, on the other hand, maintains low levels of aromatase expression primarily via promoter I.4 that lies 73 kb upstream of the common coding region. Promoters I.3 and II are used only minimally in normal breast adipose tissue. Promoters II and I.3 activities in the breast cancer, however, are strikingly increased. Additionally, the endothelial-type promoter I.7 is also upregulated in breast cancer. Thus, it appears that the prototype estrogen-dependent malignancy breast cancer takes advantage of four promoters (II, I.3, I.7 and I.4) for aromatase expression. The sum of P450arom mRNA species arising from these four promoters markedly increase total P450arom mRNA levels in breast cancer compared with the normal breast.

Adipose Tissue↗

Role of transcriptional interference in the Drosophila melanogaster Adh promoter switch.

The Drosophilia melanogaster alcohol dehydrogenase (Adh) gene is transcribed from two closely linked promoters, which are regulated by two upstream enhancers. The proximal promoter is active primarily in first to early third-instar larvae, whereas the distal promoter is active in late third-instar larvae and adults. The Adh larval enhancer and the proximal promoter are separated by the Adh adult enhancer and the distal promoter. Because the proximal promoter is turned off just as the distal promoter is turned on, we considered the possibility that the distal promoter or adult enhancer has a role in the downregulation of the proximal promoter. We report here that transcription from the distal promoter is required to shut off the proximal promoter. In the absence of the distal promoter, the proximal promoter is active throughout larval development and in adults. The proximal promoter is also aberrantly active in adults when placed upstream of the distal promoter. These results suggest that the developmental switch from proximal to distal promoter is regulated by the stage-specific activation of the distal promoter, and the subsequent repression of the proximal promoter by transcriptional interference.

Alcohol Dehydrogenase↗

Analysis of E.coli promoter structures using neural networks.

Backpropagation neural network is trained to identify E.coli promoters of all spacing classes (15 to 21). A three module approach is employed wherein the first neural net module predicts the consensus boxes, the second module aligns the promoters to a length of 65 bases and the third neural net module predicts the entire sequence of 65 bases taking care of the possible interdependencies between the bases in the promoters. The networks were trained with 106 promoters and random sequences which were 60% AT rich and tested on 126 promoters (Bacterial, Mutant and Phage promoters). The network was 98% successful in promoter recognition and 90.2% successful in non-promoter recognition when tested on 5000 randomly generated sequences. The network was further trained with 11 mutated non-promoters and 8 mutated promoters of the p22ant promoter. The testing set with 7 mutated promoters and 13 mutated non-promoters of p22ant were identified. The network was upgraded using total 1665 data of promoters and non-promoters to identify any promoter sequences in the gene sequences. The network identified the locations of P1, P2 and P3 promoters in the pBR322 plasmid. A search for the start codon, Ribosomal Binding Site and the stop codon by a string search procedure has also been added to find the possible promoters that can yield protein products. The network was also successfully tested on a synthetic plasmid pWM528.

Base Sequence↗

The health-promoting school: what role for nursing?

AIM: To review the existing literature on health-promoting schools and put forward recommendations for continuing progress. BACKGROUND: The World Health Organisation's Ottawa Charter for Health Promotion in 1986 sought to create a framework for health promotion action that conveyed the notion of capacity building as it related to specific settings. It provided the catalyst from which the health-promoting school movement emerged, against the backdrop of health professionals adapting to the changing needs and demands of clients and the evolving social context of the communities in which they live. Since then, the international health-promoting school movement has been one of the most successful of the settings-based projects and has expanded considerably over recent years. METHOD: An extensive review of available health-promoting school-related literature provides the basis for critical discussion and recommendations. FINDINGS: Traditionally, the school nursing movement has provided the backbone of nursing-related health promotion activity in the school setting. The literature, however, is generally critical of its contribution over the years - especially as its role is mainly confined to a 'conventional' health education function and has little to do with health-promoting school projects. There are more and more calls now for the school nursing service to either re-evaluate its function and processes or be devolved back into a broader primary health care practitioner role. CONCLUSION: Nurses should view the health-promoting school movement as another opportunity to embrace evolving broad-based health promotion concepts truly, as a means to forge and own their own health agenda and also as a means to move beyond a traditional reliance on a limited health education role. Schools also need to adapt and expand their efforts to focus on health promotion activities, in collaboration with the ever-widening community networks of health and social agencies. This requires the commitment of all healthcare professional groups. Nurses who practice in all settings, and not just school nurses, should be aiming to initiate and promote radical health promotion reform as set out in the health-promoting school movement. RELEVANCE TO CLINICAL PRACTICE: If health professionals wish to be at the forefront of current health-promoting school strategies they must embrace the radical health promotion reforms that are emerging from the current literature and put forward in this article. Building such group capacity, through developing social interaction, cohesion, participation and political action can only benefit the community at large and further emphasize the health promotion role of nursing. The health-promoting school movement is truly an international concept and, as such, deserves a concerted nursing representation and resourcing well beyond its current commitment.

Attitude of Health Personnel↗

Characterizing exons 11 and 1 promoters of the mu opioid receptor (Oprm) gene in transgenic mice.

BACKGROUND: The complexity of the mouse mu opioid receptor (Oprm) gene was demonstrated by the identification of multiple alternatively spliced variants and promoters. Our previous studies have identified a novel promoter, exon 11 (E11) promoter, in the mouse Oprm gene. The E11 promoter is located approximately 10 kb upstream of the exon 1 (E1) promoter. The E11 promoter controls the expression of nine splice variants in the mouse Oprm gene. Distinguished from the TATA-less E1 promoter, the E11 promoter resembles a typical TATA-containing eukaryote class II promoter. The aim of this study is to further characterize the E11 and E1 promoters in vivo using a transgenic mouse model. RESULTS: We constructed a approximately 20 kb transgenic construct in which a 3.7 kb E11 promoter region and an 8.9 kb E1 promoter region controlled expression of tau/LacZ and tau/GFP reporters, respectively. The construct was used to establish a transgenic mouse line. The expression of the reporter mRNAs, determined by a RT-PCR approach, in the transgenic mice during embryonic development displayed a temporal pattern similar to that of the endogenous promoters. X-gal staining for tau/LacZ reporter and GFP imaging for tau/GFP reporter showed that the transgenic E11 and E1 promoters were widely expressed in various regions of the central nervous system (CNS). The distribution of tau/GFP reporter in the CNS was similar to that of MOR-1-like immunoreactivity using an exon 4-specific antibody. However, differential expression of both promoters was observed in some CNS regions such as the hippocampus and substantia nigra, suggesting that the E11 and E1 promoters were regulated differently in these regions. CONCLUSION: We have generated a transgenic mouse line to study the E11 and E1 promoters in vivo using tau/LacZ and tau/GFP reporters. The reasonable relevance of the transgenic model was demonstrated by the temporal and spatial expression of the transgenes as compared to those of the endogenous transcripts. We believe that these transgenic mice will provide a useful model for further characterizing the E11 and E1 promoter in vivo under different physiological and pathological circumstances such as chronic opioid treatment and chronic pain models.

Animals↗

Analysis of nematode-responsive promoters in sugar beet hairy roots.

One of the strategies to make crops resistant to the beet cyst nematode Heterodera schachtii is the destruction of the feeding site or syncytium. This can be achieved by local expression of the cytotoxic barnase gene under control of a nematode-inducible plant promoter that is active in the syncytium. Expression of barnase outside the feeding site has to be neutralized by its inhibitor barstar driven from a constitutive promoter that is downregulated in the syncytium. Several promoters that are upregulated in feeding structures were identified using the promoter tagging strategy in Arabidopsis thaliana (Barthels et al., 1997) or by differential cDNA screening in tomato (Van der Eycken et al., 1996). Nematode downregulated promoters in Arabidopsis were described by Goddijn et al. (1993). Five nematode-induced promoters (ARM1, 1164, 728, 25 and Lemmi9) and four downregulated promoters (CaMV35S, the nopaline synthase promoter (nos) and the rooting loci promoters RolC and RolD) fused to the beta-glucuronidase (gus) reporter gene were introduced into sugar beet hairy roots by transformation with Agrobacterium rhizogenes to evaluate their expression pattern. All upregulated promoters were found to be active at the base of lateral roots. The 728 and 25 promoter were as well active in root tips. In the 25-gus lines GUS could also be detected in the vascular tissue, while the ARM1 promoter was also active in sugar beet callus. The Lemmi9 promoter and the 4 constitutive promoters were active in the entire root. The transgenic hairy roots were inoculated with Heterodera schachtii and at different time-points (4, 8, 15, 22 days after inoculation; dpi) GUS analysis was performed on the infected roots. For the ARM1, 1164 and 728 promoter the highest gus expression level in syncytia was observed at 8 dpi. In 4 days old syncytia of the 25-gus lines the intensity of the GUS signal was of the same extent as the non-specific vascular signal. In later stages it even disappeared from the feeding sites. The gus expression level in syncytia of Lemmi9-gus hairy roots was equal to that in control roots. The RolC and 35S promoter were found to be downregulated at 8 dpi, the RolD promoter at 15 dpi and the nos promoter already at 4 dpi.

Animals↗

Overview of tumor promotion in animals.

Our present understanding of two-stage carcinogenesis encompasses almost four decades of research. Evidence for chemical promotion or cocarcinogenesis was first provided by Berenblum, who reported that a regimen of croton oil (weak or noncarcinogenic) applied alternately with small doses of benzo(a)pyrene (BP) to mouse skin induced a larger number of tumors than BP alone. Subsequently, Moltram found that a single subcarcinogenic dose of BP followed by multiple applications of croton oil could induce a large number of skin tumors. These investigations as well as a number of others, such as Boutwell, Van Duuren and Hecker, were responsible in defining many important aspects of the initiation and promotion of two-stage carcinogenesis. The initiation stage in mouse skin requires only a single application of either a direct-acting carcinogen or a procarcinogen and is essentially an irreversible step which as data suggests probably involves a somatic cell mutation. The promotion stage in mouse skin can be accomplished by a wide variety of weak or noncarcinogenic agents and is initially reversible later becoming irreversible. Current information suggests that skin tumor promoters are not mutagenic but bring about a number of important epigenetic changes, such as epidermal hyperplasia, and an increase in polyamines, prostaglandins and dark basal keratinocytes as well as other embryonic conditions. Recently, tumor promotion in mouse skin was shown to consist of at least two stages, in which each stage can be accomplished by either a known promoter or a weak or nonpromoting agent. Some of the important characteristics of the first stage of promotion are: (1) only one application of a first-stage promoter, such as phorbol ester tumor promoters, calcium ionophore A23187, hydrogen peroxide and wounding is needed; (2) the action is partially irreversible; (3) an increase in dark basal keratinocytes and prostaglandins is important; and (4) such an increase can be inhibited by antiinflammatory steroids and protease inhibitors. The second stage of promotion is initially reversible but later becomes irreversible. Polyamines and epidermal cell proliferation are important events in the second stage of promotion. A number of weak or nonpromoting agents, such as mezerein, are effective second-stage promoters which can be counteracted by retinoic acid, antiinflammatory steroids and polyamine synthesis inhibitors. Although skin tumor promotion has been extensively studied in mice, not all strains and stocks of mice are susceptible to phorbol ester tumor promoters. In this regard, the C57BL/6 mice appear to be fairly resistant to phorbol ester tumor promoters. In addition, not all species are equally susceptible to phorbol ester tumor promotion. Recently the generality of the two-stage system of inducing tumors has been shown to exist in a number of experimental carcinogenesis systems, such as the liver, bladder, lung, colon, esophagus, stomach, mammary gland, pancreas and cells in culture. In these systems, a wide variety of promoting agents such as diet, bile acids, hormones, saccharin, tryptophan, phenobarbital, polychlorinated biphenyls, polybrominated biphenyls and butylated hydroxytoluene have been used to accomplish the tumor promotion stage. It is not presently known if other experimental carcinogenesis systems and the induction of human cancer involves a series of stages similar to that in the mouse skin.

Animals↗

Chronic exposure to ionizing radiation as a tumor promoter in mouse skin.

We have tested chronic exposure to 90Y beta radiation for its action as a complete tumor promoter, a stage I tumor promoter, or a stage II tumor promoter in SENCAR mouse skin. In skin initiated with a single application of 7,12,dimethylbenz[a]anthracene (DMBA, 10 nmol), chronic exposure to beta radiation as a complete promoter (0.5 Gy, twice/week, 13 weeks) produced no tumors and, when added to a complete chemical promoter (TPA), reduced tumor frequency about 30%. A similar result was observed when beta radiation was tested as a stage II promoter. DMBA-initiated mice that received chemical (12-O-tetradecanoylphorbol-13-acetate, TPA) stage I promotion followed by 13 weeks of beta-radiation exposure (0.5 Gy, twice/week) as stage II promotion produced essentially no tumors, and combining the same chronic beta-radiation exposure with chemical (mezerein) stage II promotion reduced tumor frequency about 20% when compared to a similar group that was not irradiated. Chronic beta-radiation exposure was tested two ways as a stage I tumor promoter in initiated skin that was subsequently treated with mezerein as a stage II promoter. Stage I promotion was shown to proceed with the passage of time, indicating this process occurs naturally in the absence of chemical or physical stimulation. Hyperthermia, previously shown to be a potent inhibitor of chemically stimulated stage I promotion, had no effect on the natural process, indicating at least some differences in mechanism between the two processes. The natural process was, in fact, inhibited by chemical tumor promoters, but not by radiation. In addition to the increase resulting from this natural process, tumor frequency was further increased slightly but significantly (12-15%, P less than or equal to 0.05) when chronic radiation exposure was given as a stage I promoter (0.5 Gy, twice/week, 13 weeks) subsequent to initiation, in spite of the expected 20% reduction resulting from this dose. Exposure of initiated animals to radiation (0.5 or 1.0 Gy, twice/week, 2 weeks) in addition to TPA as stage I promotion produced a similar increase in tumor frequency (P less than 0.02). At higher radiation doses, however, tumor frequency was reduced compared to unirradiated controls. In a third test as a stage I promoter, beta radiation (0.5 Gy twice/week, 4 weeks) was given prior to initiation with N-methyl-N'-nitro-N-nitrosoguanidine in animals subsequently promoted by TPA (twice/week, 13 weeks), and again the radiation slightly but significantly (P less than 0.03) increased tumor frequency compared to the unirradiated control group.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Comparison of promoter region constructs for in vivo intramuscular expression.

BACKGROUND: High transgene expression is generally expected after gene transfer. However, different level, kinetics and localization of expression might be needed for relevant therapeutic applications. Former studies have compared various promoter regions driving gene expression leading to conflicting results. In the present work, two promoter families have been compared using the efficient in vivo intramuscular electrotransfer technique. METHODS: Three promoter regions were constructed by associating the strong ubiquitous cytomegalovirus (CMV) enhancer-promoter to its homologous intron A or to a heterologous intron, or to a hybrid intron. Promoter regions derived from the muscle creatine kinase (MCK) promoter were also studied. The expression of the same transgene (SeAP or neurotrophin-3) under control of these different promoters was compared after plasmid electrotransfer in mouse tibialis-cranialis skeletal muscle. RESULTS: Heterologous intron association to the CMV promoter did not modify gene expression kinetics nor increase gene expression level. Usefulness of intron A or hybrid intron association to the CMV promoter depended on the gene. The various MCK promoters drove efficient gene expression but lower than that obtained with the CMV promoter. Furthermore, peak value was reached earlier with MCK promoter regions (14 days). CONCLUSION: For applications of gene transfer restricted to skeletal muscle, the MCK promoter or a MCK promoter variant would be a promising alternative to the CMV promoter. Indeed, it has been demonstrated that the use of MCK promoter limits humoral and cell-mediated immune responses. Furthermore, the MCK promoter decreases the initial expression peak that may be detrimental, drives a sustained gene expression, and improves gene transfer safety.

Alkaline Phosphatase↗

Predicting Pol II promoter sequences using transcription factor binding sites.

A computer program, PROMOTER SCAN, has been developed to recognize a high percentage of Pol II promoter sequences while allowing only a small rate of false positives. A total of 167 primate Pol II promoter sequences, obtained from the Eukaryotic Promoter Database, and 999 primate non-promoter sequences, obtained from the GenBank sequence databank, were used in the analysis. Both promoter and non-promoter sequences were analyzed for the comparative density of each unique mammalian transcription factor binding site listed in the Ghosh Transcription Factor Database. The density of each of these binding sites was then used to derive a ratio of density of each transcriptional element in promoter compared to non-promoter sequences. The combined individual density ratios of all binding sites were then collectively used to build a scoring profile called the Promoter Recognition Profile. This profile, used in combination with a weighted matrix for scoring a TATA box, was then used by the PROMOTER SCAN program to test the prediction of promoter sequences and the ability of the computer program to discriminate them from non-promoter sequences. When the promoter cutoff score was set so that 70% of promoters were recognized correctly by the program, a false positive rate of about 1/5600 bases was observed in the non-promoter sequence set. PROMOTER SCAN is now being developed for public distribution.

Algorithms↗

Reactivation of the methylation-inactivated late E2A promoter of adenovirus type 2 by E1A (13 S) functions.

The inactivating effect of sequence-specific promoter methylations was extensively studied by using the late E2A promoter of adenovirus type 2 (Ad2) DNA. The modification of the three 5' CCGG 3' sequences at nucleotides +24, +6 and -215, relative to the cap site in this promoter, sufficed to silence the gene in transient expression either in Xenopus laevis oocytes or in mammalian cells, and after the fixation of the E2A promoter-chloramphenicol-acetyltransferase (CAT) gene construct in the genome of hamster cells. It will now be demonstrated that the inactivation of the late promoter of Ad2 DNA can be reversed by transactivating functions that are encoded in the 13S messenger RNA of the E1A region of Ad2 DNA. The reactivation of a methylation-inactivated eukaryotic promoter by transactivating functions has general significance in that the value of a regulatory signal can be fully realized only by its controlled reversibility. It was demonstrated in transient expression experiments that the 5' CCGG 3'-methylated late E2A promoter was at least partly reactivated in cell lines constitutively expressing the E1 region of Ad2 or of adenovirus type 5 (Ad5) DNA. The reactivation led to transcriptional initiation at the authentic cap sites of the late E2A promoter and was not associated with promoter demethylation, at least not in both DNA complements. Reactivation of the methylation-inactivated E2A promoter could also be demonstrated in two BHK21 cell lines (mc14 and mc20), which carried the late E2A promoter-CAT gene assembly in an integrated form. In these cell lines the late E2A promoter was methylated and the CAT gene was not expressed. By transfection of cell lines mc14 and mc20, the reactivating functions were shown to reside in the pAd2E1A-13 S cDNA clone of Ad2 DNA. The pAd2E1A-12 S cDNA clone or the pAd2E1B clone showed no reactivating function. These findings implicated the E1A 289 amino acid residue protein of Ad2, a well-known transactivator, as the reactivating function of the endogenous, previously dormant, late E2A promoter-CAT gene assembly. The methylated promoter was not demethylated, at least not in both complements, and it was shown that reactivation of the methylated promoter entailed transcriptional initiation at the authentic late E2A cap site. Since E1A and E1B jointly had a more pronounced effect, it was conceivable that genes in both regions acted together in the abrogation of the inhibitory effect of promoter methylations in the late E2A promoter.

Adenoviridae↗

A statistical analysis of the magnitude and composition of drug promotion in the United States in 1998.

BACKGROUND: Although pharmaceutical industry marketing and other factors may influence physician decisions regarding medication prescribing in the United States, little information is available about the composition of promotional efforts by promotional mode and medication class. OBJECTIVES: The aims of this study were to determine the magnitude of expenditures for common modes of promotion and to delineate patterns of promotional strategies for particular classes of medications. METHODS: Nationally representative data on expenditures (in US $) for the 250 most promoted medications in the United States in 1998 were available from an independent pharmaceutical market research company for the 5 most commonly used modes of promotion. Key patterns of drug promotion were identified by descriptive statistics, a cluster analysis of expenditures by class, and an analysis of expenditure concentration. RESULTS: In 1998, the pharmaceutical industry spent $12,724 million promoting its products in the United States, of which 85.9% was accounted for by the top 250 drugs and 51.6% by the top 50 drugs. Direct-to-consumer (DTC) advertising was more concentrated on a small subset of medications than was promotion to professionals. Overall, 1998 expenditures were dominated by free drug samples provided to physicians (equivalent retail cost of $6602 million) and office promotion ($3537 million), followed by DTC advertising ($1337 million), hospital promotion ($705 million), and advertising in medical journals ($540 million). Four distinct patterns of expenditures were observed: promotion to office physicians with little consumer promotion (14 drug classes); dual focus on office physicians and consumer advertising (4 drug classes); predominant DTC advertising (1 class: smoking-cessation products); and promotion to office- and hospital-based professionals without consumer advertising (1 class: narcotic analgesics). CONCLUSIONS: The present findings reinforce the perception that the pharmaceutical industry invests heavily in promoting its products and demonstrates that promotional expenditures are concentrated on a small number of medications. Although promotion to professionals remains dominant, DTC advertising has become key for a subset of common medications

Advertising↗

Transgenic sterility in Populus: expression properties of the poplar PTLF, Agrobacterium NOS and two minimal 35S promoters in vegetative tissues.

Transgenic sterility is a desirable trait for containment of many kinds of transgenes and exotic species. Genetically engineered floral sterility can be imparted by expression of a cytotoxin under the control of a predominantly floral-tissue-specific promoter. However, many otherwise desirable floral promoters impart substantial non-floral expression, which can impair plant health or make it impossible to regenerate transgenic plants. We are therefore developing a floral sterility system that is capable of attenuating undesired background vegetative expression. As a first step towards this goal, we compared the vegetative expression properties of the promoter of the poplar (Populus trichocarpa Torr. & Gray) homolog of the floral homeotic gene LEAFY (PTLF), which could be used to impart male and female flower sterility, to that of three candidate attenuator-gene promoters: the cauliflower mosaic virus (CaMV) 35S basal promoter, the CaMV 35S basal promoter fused to the TMV omega element and the nopaline synthase (NOS) promoter. The promoters were evaluated via promoter::GUS gene fusions in a transgenic poplar hybrid (Populus tremula L. x P. alba L.) by both histochemical and fluorometric GUS assays. In leaves, the NOS promoter conveyed the highest activity and had a mean expression level 5-fold higher than PTLF, whereas the CaMV 35S basal promoter fused to the omega element and the CaMV 35S basal promoter alone directed mean expression levels that were 0.5x and 0.35x that of PTLF, respectively. Differential expression in shoots, leaves, stems and roots was observed only for the NOS and PTLF promoters. Strongest expression was observed in roots for the NOS promoter, whereas the PTLF promoter directed highest expression in shoots. The NOS promoter appears best suited to counteract vegetative expression of a cytotoxin driven by the PTLF promoter where 1:1 toxin:attenuator expression is required.

Amino Acid Oxidoreductases↗

Identification of the in vivo promoters of bacteriophages S13 and phi X174 and measurement of their relative activities.

Regions of bacteriophages phi X174 and S13 that contain putative promoter sequences were amplified by the polymerase chain reaction (PCR) and cloned into the reporter vector pKO-1. Assays of galactokinase activity revealed in vivo promoter activity in those constructs containing the promoter sequences with transcription initiation (+1) sites at nucleotide positions 45, 982, 1823, and 5211. These were identical in location to sequences with in vitro promoter activity and to the three known promoters PA, PB, and PD. P5211 is the location of a new, fourth, promoter. A site with a +1 position at nucleotide 4876, previously shown to initiate RNA synthesis in an in vitro run-off transcription assay, had no in vivo promoter activity. To investigate whether flanking sequences had effects on promoter activity, restriction fragments of phi X174 and S13 that encompass the in vivo promoters were cloned into the reporter vector pKO-1. The PA and P5211 promoter constructs showed dramatic effects with increases in activity of up to 7 times that shown with the PCR-generated promoter constructs. The phi X174 PB promoter construct had a 50% decrease in activity compared with the PCR-generated PB clone. While the data showed that in most instances promoter activity is affected by the flanking sequences in which the promoter is embedded, no general pattern correlating flanking sequences and promoter activity could be discerned. Additional evidence that the promoter sequence regions were active in vivo promoters was obtained by S1 nuclease mapping experiments. Initiation of RNA synthesis was shown at positions 45, 982, and 5211.

Bacteriophage phi X 174↗