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11.
12.
Gabriel Gutiérrez Josep Casadesús Jose L. Oliver Antonio Marine 《Journal of molecular evolution》1994,39(4):340-346
E. coli genes that contain a high frequency of the tetranucleotide CTAG are also rich in the tetramers CTTG, CCTA, CCAA, TTGG, TAGG, and CAAG (group-I tetramers). Conversely, E. coli genes lacking CTAG are rich in the tetranucleotides CCTG, CCAG, CTGG, and CAGG (group-II tetramers). These two gene samples differ also in codon usage, amino acid composition, frequency of Dcm sites, and contrast vocabularies. Group-I tetramers have in common that they are depleted by very-short-patch repair (VSP), while group-II tetramers are favored by VSP activity. The VSP system repairs G:T mismatches to G:C, thereby increasing the overall G+C content of the genome; for this reason the CTAG-rich sample has a lower G+C content than the CTAG-poor sample. This compositional heterogeneity can be tentatively explained by a low level of VSP activity on the CTAG-rich sample. A negative correlation is found between the frequency of group-I tetramers and the level of gene expression, as measured by the Codon Adaptation Index (CAI). A possible link between the rate of VSP activity and the level of gene expression is considered.Correspondence to: A. Marine 相似文献
13.
Qiyuan Chen Melanie Smith Tam Nguyen Darryl W. Maher Peter Hersey 《Cancer immunology, immunotherapy : CII》1994,38(6):385-393
Previous studies have shown that recognition of melanoma by cytotoxic T lymphocytes may be restricted by HLA-A1, A2 and other HLA antigens. The present study examined the cytotoxic specificity and major histocompatibility complex restriction of cloned cytotoxic T lymphocytes (CTL) isolated from a patient with the HLA phenotype A3,31 who had been immunized with a vaccine prepared from HLA-A1,3 melanoma cells. Cytotoxic assays against HLA-typed allogeneic melanoma cells indicated that cloned CTL from the patient were able to kill allogeneic melanoma cells expressing HLA-A1 but not other HLA-A1-positive cells. Studies on a representative clone indicated that proliferation and cytokine (tumour necrosis factor ) production in response to melanoma cells was also associated with HLA-A1 on melanoma cells. Response to the melanoma cells was associated with interleukin-4 (IL-4) rather than IL-2 production. The antigen recognized in the context of HLA-A1 on allogeneic melanoma cells was detected in cytotoxic assays on cells from 9 of 12 HLA-A1+ melanoma cell lines and did not appear to be the product of the MAGE-1 or-3 genes. These findings suggest that T cells can recognize melanoma antigens in the context of alloantigens and that allogeneic vaccines containing immunodominant alloantigens may generate CTL that are ineffective against autologous melanoma. The study does not, however, exclude the possibility that CTL with specificity to the latter may be activated by allogeneic vaccines, and further studies are needed to answer this question. 相似文献
14.
David J. Munroe Melanie Haas Eva Bric Tania Whitton Hiroyuki Aburatani Kent Hunter David Ward David E. Housman 《Genomics》1994,19(3)
A significant issue in the analysis of any genomic DNA segment is the generation of a unique set of short single-copy sequences that are representative of that region. In this report we describe a novel technique, IRE-bubble PCR, which was designed to amplify the human DNA content of somatic cell hybrids, YACs, cosmids, and λ phage and result in greater complexity and representation than standard inter-IRE, PCR. Here we demonstrate that IRE-bubble PCR is species specific and that it results in the generation of a product that is at least 10-fold more complex and representative than that produced by standard inter-IRE PCR. In addition, we have addressed the factors that contribute to the representation of the IRE-bubble PCR product and show how they may be used to further increase the complexity of this reaction. Finally, we have illustrated how the complexity and distribution of products generated by IRE-bubble PCR can be exploited and applied to FISH mapping and "chromosome painting" as well as to the generation of STSs targeted to specific chromosomal or subchromosomal regions. 相似文献
15.
Elena P. Sawin Harold B. Dowse Melanie J. Hamblen-Coyle Jeffery C. Hall Marla B. Sokolowski 《Journal of Insect Behavior》1994,7(3):249-262
We examined the locomotor activity ofDrosophila melanogaster for the existence of circadian rhythms, using the wild type and two mutants of theperiod (per) gene,per
o andper
s. This was accomplished using a newly described apparatus for the recording and measurement of larval path lengths over a 96-h test period. None of the larvae examined exhibited appreciable diel rhythms under cycling conditions of light or temperature. Larvae were also not rhythmic under free-running conditions. Our results suggest that theper gene does not influence an observable locomotor behavioral phenotype in the larval stage of development. 相似文献
16.
David W. Kikuchi William L. Allen Kevin Arbuckle Thomas G. Aubier Emmanuelle S. Briolat Emily R. Burdfield-Steel Karen L. Cheney Klára Daňková Marianne Elias Liisa Hämäläinen Marie E. Herberstein Thomas J. Hossie Mathieu Joron Krushnamegh Kunte Brian C. Leavell Carita Lindstedt Ugo Lorioux-Chevalier Melanie McClure Callum F. McLellan Iliana Medina Viraj Nawge Erika Páez Arka Pal Stano Pekár Olivier Penacchio Jan Raška Tom Reader Bibiana Rojas Katja H. Rönkä Daniela C. Rößler Candy Rowe Hannah M. Rowland Arlety Roy Kaitlin A. Schaal Thomas N. Sherratt John Skelhorn Hannah R. Smart Ted Stankowich Amanda M. Stefan Kyle Summers Christopher H. Taylor Rose Thorogood Kate Umbers Anne E. Winters Justin Yeager Alice Exnerová 《Journal of evolutionary biology》2023,36(7):975-991
Prey seldom rely on a single type of antipredator defence, often using multiple defences to avoid predation. In many cases, selection in different contexts may favour the evolution of multiple defences in a prey. However, a prey may use multiple defences to protect itself during a single predator encounter. Such “defence portfolios” that defend prey against a single instance of predation are distributed across and within successive stages of the predation sequence (encounter, detection, identification, approach (attack), subjugation and consumption). We contend that at present, our understanding of defence portfolio evolution is incomplete, and seen from the fragmentary perspective of specific sensory systems (e.g., visual) or specific types of defences (especially aposematism). In this review, we aim to build a comprehensive framework for conceptualizing the evolution of multiple prey defences, beginning with hypotheses for the evolution of multiple defences in general, and defence portfolios in particular. We then examine idealized models of resource trade-offs and functional interactions between traits, along with evidence supporting them. We find that defence portfolios are constrained by resource allocation to other aspects of life history, as well as functional incompatibilities between different defences. We also find that selection is likely to favour combinations of defences that have synergistic effects on predator behaviour and prey survival. Next, we examine specific aspects of prey ecology, genetics and development, and predator cognition that modify the predictions of current hypotheses or introduce competing hypotheses. We outline schema for gathering data on the distribution of prey defences across species and geography, determining how multiple defences are produced, and testing the proximate mechanisms by which multiple prey defences impact predator behaviour. Adopting these approaches will strengthen our understanding of multiple defensive strategies. 相似文献
17.
Maja Wiprächtiger Melanie Haupt Andreas Froemelt Magdalena Klotz Claudio Beretta Dominik Osterwalder Vanessa Burg Stefanie Hellweg 《Journal of Industrial Ecology》2023,27(1):254-271
Industrial ecology (IE) methodologies, such as input/output or material flow analysis and life cycle assessment (LCA), are often used for the environmental evaluation of circular economy strategies. Up to now, an approach that utilizes these methods in a systematic, integrated framework for a holistic assessment of a geographic region's sustainable circular economy potential has been lacking. The approach developed in this study (IE4CE approach) combines IE methodologies to determine the environmental impact mitigation potential of circular economy strategies for a defined geographic region. The approach foresees five steps. First, input/output analysis helps identify sectors with high environmental impacts. Second, a refined analysis is conducted using material flow and LCA. In step 3, circular strategies are used for scenario design and evaluated in step 4. In step 5, the assessment results are compiled and compared across sectors. The approach was applied to a case study of Switzerland, analyzing 8 sectors and more than 30 scenarios in depth. Carbon capture and storage (CCS) from waste incineration, biogas and cement production, food waste prevention in households, hospitality and production, and the increased recycling of plastics had the highest mitigation potential. Most of the scenarios do not influence each other. One exception is the CCS scenarios: waste avoidance scenarios decrease the reduction potential of CCS. A combination of scenarios from different sectors, including their impact on the CCS scenario potential, led to an environmental impact mitigation potential of 11.9 Mt CO2-eq for 2050, which equals 14% of Switzerland's current consumption-based impacts. 相似文献
18.
Melanie R. Maas 《Journal of industrial microbiology & biotechnology》1993,12(3-5):162-167
Summary In the processed meat industry, food safety and microbiological shelf life issues lend themselves to the use of probability modeling. Our research concentrated on predicting the effectiveness of sodium lactate as an antibotulinal agent in vacuum packaged, uncured and cured turkey breast model systems. In uncured turkey breast containing 1.4% NaCl, 0.3% Na phosphate, and 0–3% Na lactate, the antibotulinal effect of sodium lactate can be predicted using the following model: Days to toxicity = 3.13+0.39(Na lactate)2. Using cured turkey breast with 0.3% Na phosphate, 0.2% sucrose, 0–3% Na lactate, the time to toxicity can be predicted from the following model: Days to toxicity = 1.69+4.88(NaCl)–11.16(Na lactate)+7.23(Na lactate)2. Probability models have also been developed to predict the refrigerated shelf life of specific processed meat products. The usefulness of the predictive modeling for food safety and quality in the food industry will also be discussed.This paper was presented at The International Conference on the Application of Predictive Microbiology and Computer Modeling Techniques to the Food Industry, April 12–15 1992, Hyatt Regency Hotel, Tampa, FL, USA. 相似文献
19.
20.
Jérémy Gauthier Joana Meier Fabrice Legeai Melanie McClure Annabel Whibley Anthony Bretaudeau Hélène Boulain Hugues Parrinello Sam T. Mugford Richard Durbin Chenxi Zhou Shane McCarthy Christopher W. Wheat Florence Piron-Prunier Christelle Monsempes Marie-Christine François Paul Jay Camille Noûs Emma Persyn Emmanuelle Jacquin-Joly Camille Meslin Nicolas Montagné Claire Lemaitre Marianne Elias 《Molecular ecology resources》2023,23(4):872-885
The ithomiine butterflies (Nymphalidae: Danainae) represent the largest known radiation of Müllerian mimetic butterflies. They dominate by number the mimetic butterfly communities, which include species such as the iconic neotropical Heliconius genus. Recent studies on the ecology and genetics of speciation in Ithomiini have suggested that sexual pheromones, colour pattern and perhaps hostplant could drive reproductive isolation. However, no reference genome was available for Ithomiini, which has hindered further exploration on the genetic architecture of these candidate traits, and more generally on the genomic patterns of divergence. Here, we generated high-quality, chromosome-scale genome assemblies for two Melinaea species, M. marsaeus and M. menophilus, and a draft genome of the species Ithomia salapia. We obtained genomes with a size ranging from 396 to 503 Mb across the three species and scaffold N50 of 40.5 and 23.2 Mb for the two chromosome-scale assemblies. Using collinearity analyses we identified massive rearrangements between the two closely related Melinaea species. An annotation of transposable elements and gene content was performed, as well as a specialist annotation to target chemosensory genes, which is crucial for host plant detection and mate recognition in mimetic species. A comparative genomic approach revealed independent gene expansions in ithomiines and particularly in gustatory receptor genes. These first three genomes of ithomiine mimetic butterflies constitute a valuable addition and a welcome comparison to existing biological models such as Heliconius, and will enable further understanding of the mechanisms of adaptation in butterflies. 相似文献