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41.
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
42.
Naresh Kumar Aniket Saraf Sagarika Pal Deeksha Mishra Prashant Singh Jeffrey R. Johansen 《Journal of phycology》2023,59(1):204-220
Three novel strains in Calotrichaceae from tropical habitats were isolated and characterized with regard to their morphology, phylogenetic placement, and secondary structures of conserved domains in the 16S-23S internal transcribed spacer (ITS). The strains fell into two clades formerly identified as Calothrix from freshwater and brackish habitats. Based on both morphology and ecology, they differed from the type species of Calothrix, C. confervicola, which is marine, has wide trichomes with short cells, and narrows abruptly to a hyaline hair. The first clade grouped species with heteropolar filaments widened at the base and narrowed gradually toward the apex but not ending in a hair, with basal heterocytes that are formed in series as the apically placed heterocytes senesce; this clade is being named Fulbrightiella gen. nov., with two named species, F. bharadwajae sp. nov. and F. oahuensis sp. nov. The second clade was comprised of a single species with isopolar trichomes that are untapering as hormogonia, but which widen midfilament and taper toward both ends following growth. These trichomes develop pairs of heterocyte mid-filament, causing fragmentation into heteropolar trichomes with basal heterocytes and ends that taper, but not to a hair. This clade consists of a single species at present, Sherwoodiella mauiensis. With this action, four clades in the Calotrichaceae have been named: Macrochaete, Dulcicalothrix, Fulbrightiella, and Sherwoodiella. Calothrix sensu stricto is truly marine, morphologically distinct, and unsequenced; finding and sequencing the generitype for Calothrix remains as the most important and unfinished task in the revision of the Calotrichaceae. 相似文献
43.
Sangita Pal D. Sasmal B. Guhathakurta G.B. Nair S.K. Bhattacharya R. Mallick A. Datta 《FEMS immunology and medical microbiology》1996,15(2-3):143-148
Abstract The outer membrane (OM) protein components of a Vibrio cholerae O1 and four V. cholerae O139 strains, collected from cholera patients, were analysed by SDS-PAGE. A protein of 69 kDa molecular mass was observed only when the OMPs were prepared from strains grown in synthetic broth. As a result of passage in the rabbit ileal loop (RIL), virulence was enhanced, and a protein component around 18 kDa of the V. cholerae O139 OM became the major protein component. On immunoblot analysis with rabbit antiserum against V. cholerae O139 OM, it was shown that, apart from the major protein component of V. cholerae O1 OM of around 45 kDa and that of V. cholerae O139 OM of around 38 kDa, all other minor protein components were cross-reactive between the two serogroups. In immunoblot assays with convalescent sera obtained from V. cholerae O139-infected patients, it was observed that in addition to the lipopolysaccharide (LPS)-induced antibody, only the 38 kDa major protein component elicited considerable levels of antibody in the pateint. Minor OM components of 18 kDa were detected in the immunoblot analysis by LPS-directed antibody, however, as the OM proteins are known to be associated with LPS. 相似文献
44.
Minakshi Basu K. Pal A. S. Malhotra R. Prasad R. C. Sawhney 《International journal of biometeorology》1995,39(1):17-21
Alterations in circulatory levels of total T4 (TT4), total T3 (TT3), free T4 (FT4), free T3 (FT3), thyrotropin (TSH) and T3 uptake (T3U) were studied in male and female sea-level residents (SLR) at sea level, in Armed forces personnel staying at high altitude (3750 m) for prolonged duration (acclimatized lowlanders, ALL) and in high-altitude natives (HAN). Identical studies were also performed on male ALL who trekked to an extreme altitude of 5080 m and stayed at an altitude of more than 6300 m for about 6 months. The total as well as free thyroid hormones were found to be significantly higher in ALL and HAN as compared to SLR values. Both male as well as female HAN had higher levels of thyroid hormones. The rise in hormone levels in different ALL ethnic groups drawn from amongst the southern and northern parts of the country was more or less identical. In both HAN and ALL a decline in FT3 and FT4 occurred when these subjects trekked at subzero temperatures to extreme altitude of 5080 m but the levels were found to be higher in ALL who stayed at 6300 m for a prolonged duration. Plasma TSH did not show any appreciable change at lower altitudes but was found to be decreased at extreme altitude. The increase in thyroid hormones at high altitude was not due to an increase in hormone binding proteins, since T3U was found to be higher at high altitudes. A decline in TSH and hormone binding proteins and an increase in the free moiety of the hormones is indicative of a subtle degree of tissue hyperthyroidism which may be playing an important role in combating the extreme cold and hypoxic environment of high altitudes. 相似文献
45.
46.
A negative selection scheme based on the expression of cytosine deaminase in plastids 总被引:2,自引:0,他引:2
The enzyme cytosine deaminase (CD) encoded by codA catalyzes deamination of cytosine to uracil. CD is present in prokaryotes and in many eukaryotic micro-organisms, but is absent in higher plants. 5-fluorocytosine (5FC) is metabolized in CD-expressing cells, causing cellular death. A chimeric codA has been introduced into the tobacco plastid genome and 5FC was used to select against tissue culture cells and seedlings expressing CD. This negative selection scheme will be useful in identifying nuclear genes which control plastid gene expression in higher plants. 相似文献
47.
P-Element Insertion Alleles of Essential Genes on the Third Chromosome of Drosophila Melanogaster: Correlation of Physical and Cytogenetic Maps in Chromosomal Region 86e-87f 总被引:2,自引:0,他引:2 下载免费PDF全文
P. Deak M. M. Omar RDC. Saunders M. Pal O. Komonyi J. Szidonya P. Maroy Y. Zhang M. Ashburner P. Benos C. Savakis I. Siden-Kiamos C. Louis V. N. Bolshakov F. C. Kafatos E. Madueno J. Modolell D. M. Glover 《Genetics》1997,147(4):1697-1722
We have established a collection of 2460 lethal or semi-lethal mutant lines using a procedure thought to insert single P elements into vital genes on the third chromosome of Drosophila melanogaster. More than 1200 randomly selected lines were examined by in situ hybridization and 90% found to contain single insertions at sites that mark 89% of all lettered subdivisions of the Bridges' map. A set of chromosomal deficiencies that collectively uncover ~25% of the euchromatin of chromosome 3 reveal lethal mutations in 468 lines corresponding to 145 complementation groups. We undertook a detailed analysis of the cytogenetic interval 86E-87F and identified 87 P-element-induced mutations falling into 38 complementation groups, 16 of which correspond to previously known genes. Twenty-one of these 38 complementation groups have at least one allele that has a P-element insertion at a position consistent with the cytogenetics of the locus. We have rescued P elements and flanking chromosomal sequences from the 86E-87F region in 35 lines with either lethal or genetically silent P insertions, and used these as probes to identify cosmids and P1 clones from the Drosophila genome projects. This has tied together the physical and genetic maps and has linked 44 previously identified cosmid contigs into seven ``supercontigs' that span the interval. STS data for sequences flanking one side of the P-element insertions in 49 lines has identified insertions in the αγ element at 87C, two known transposable elements, and the open reading frames of seven putative single copy genes. These correspond to five known genes in this interval, and two genes identified by the homology of their predicted products to known proteins from other organisms. 相似文献
48.
Induction of neuronal type nitric oxide synthase in skeletal muscle by chronic electrical stimulation in vivo 总被引:2,自引:0,他引:2
Reiser, Peter J., William O. Kline, and Pal L. Vaghy.Induction of neuronal type nitric oxide synthase in skeletal muscle by chronic electrical stimulation in vivo. J. Appl. Physiol. 82(4): 1250-1255, 1997.Fast-twitch skeletal muscles contain more neuronal-type nitricoxide synthase (nNOS) than slow-twitch muscles because nNOS is presentonly in fast (type II) muscle fibers. Chronic in vivo electricalstimulation of tibialis anterior and extensor digitorum longus musclesof rabbits was used as a method of inducing fast-to-slow fiber typetransformation. We have studied whether an increase in musclecontractile activity induced by electrical stimulation alters nNOSexpression, and if so, whether the nNOS expression decreases to thelevels present in slow muscles. Changes in the expression of myosinheavy chain isoforms and maximum velocity of shortening of skinnedfibers indicated characteristic fast-to-slow fiber type transformationafter 3 wk of stimulation. At the same time, activity of NOS doubled inthe stimulated muscles, and this correlated with an increase in theexpression of nNOS shown by immunoblot analysis. These data suggestthat nNOS expression in skeletal muscle is regulated by muscle activityand that this regulation does not necessarily follow the fast-twitchand slow-twitch pattern during the dynamic phase of phenotypetransformation. 相似文献
49.
Summary A new mutation strategy, which involves -irradiation of cells followed by a selective enzymatic enrichment step, was worked out to obtain auxotrophic mutants from the astaxanthin-producing yeast P. rhodozyma. Under the optimized conditions described, different mutants suitable for strain improvement were isolated. 相似文献
50.
M. Pal A. M. Calvo M. C. Terrón A. E. González 《World journal of microbiology & biotechnology》1995,11(5):541-545
The mushroom Flammulina velutipes and the white-rot fungus Trametes versicolor were cultivated separately on sugarcane bagasse for 40 days. Trametes versicolor produced laccase and manganese-peroxidase activities, showing a simultaneous degradation of lignin and holocellulose. However, only phenoloxidase activity was found with Flammulina velutipes. A preferential degradation of lignin was detected in F. velutipes, which exhibited a greater reduction in the ratio of weight loss to lignin loss than T. versicolor. A decrease in the syringyl/guaiacyl ratio observed with both fungi indicated the preferential degradation of non-condensed (syringyl-type) lignin units. An increase in the relative abundance of aromatic carboxylic acids suggested that the oxidative transformation of lignin unit side-chains was occurring. This was more noticeable with Flammulina velutipes than with T. versicolor. 相似文献