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Journal articles on the topic 'Coloration impaire'
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1
Webster, Richard J., Christopher Hassall, Chris M. Herdman, Jean-Guy J. Godin, and Thomas N. Sherratt. "Disruptive camouflage impairs object recognition." Biology Letters 9, no. 6 (December 23, 2013): 20130501. http://dx.doi.org/10.1098/rsbl.2013.0501.
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Whether hiding from predators, or avoiding battlefield casualties, camouflage is widely employed to prevent detection. Disruptive coloration is a seemingly well-known camouflage mechanism proposed to function by breaking up an object's salient features (for example their characteristic outline), rendering objects more difficult to recognize. However, while a wide range of animals are thought to evade detection using disruptive patterns, there is no direct experimental evidence that disruptive coloration impairs recognition. Using humans searching for computer-generated moth targets, we demonstrate that the number of edge-intersecting patches on a target reduces the likelihood of it being detected, even at the expense of reduced background matching. Crucially, eye-tracking data show that targets with more edge-intersecting patches were looked at for longer periods prior to attack, and passed-over more frequently during search tasks. We therefore show directly that edge patches enhance survivorship by impairing recognition, confirming that disruptive coloration is a distinct camouflage strategy, not simply an artefact of background matching.
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Marshall, Kate L. A., Kate E. Philpot, and Martin Stevens. "Conspicuous male coloration impairs survival against avian predators in Aegean wall lizards, Podarcis erhardii." Ecology and Evolution 5, no. 18 (September 2015): 4115–31. http://dx.doi.org/10.1002/ece3.1650.
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Adakole, John Ameh, and J. B. Balogun. "Acute ecotoxicity of aqueous and ethanolic extract of leaves of <i>Khaya senegalensis</i> on chironomid larvae." Brazilian Journal of Aquatic Science and Technology 15, no. 2 (December 19, 2011): 41–45. http://dx.doi.org/10.14210/bjast.v15n2.p41-45.
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Protection of aquatic habitat requires an understanding of both the sensitivity of invertebrates to contaminants and their ecological requirements. Phyto-chemical screening of the leaves of extract of Khaya senegalensis revealed the presence of active constituents. Acute ecotoxicities of aqueous and ethanolic extracts of leaves of Khaya senegalensis to Chironomid larvae were evaluated by static bioassay. Bioactivity of the ethanolic extract was found to be greater than the aqueous extract. The LC50 of aqueous and ethanolic extracts were 1.39g/l and 1.20g/l respectively. Stressful behaviors exhibited by the chironomids include deformity of mouthparts, certain body segments being filled with black particles and change in body coloration. All behaviors were dose-dependent. The larvae were not repelled by the extract, indicating that antifeedant activity was not a mortality factor. Mortality was probably due to the disappearance of the reddish coloration of the hemoglobin component and consequently impaired metabolism of the larvae. The results were discussed and compared with those of other studies.
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Kermicle, Jerry L., and Mary Alleman. "Gametic imprinting in maize in relation to the angiosperm life cycle." Development 108, Supplement (April 1, 1990): 9–14. http://dx.doi.org/10.1242/dev.108.supplement.9.
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Differences in the activity of maternally and paternally derived genomes in maize endosperm have been observed at three levels of genetic manipulation. When the balance of entire chromosome sets departs from the standard ratio of two of maternal origin to one of paternal origin, development is impaired, often leading to seed failure. At the level of individual chromosomes, absence of a paternal representative for 8 of the 19 chromosome arms tested causes a marked reduction in kernel size. Replacement of the missing arms by ones of maternal origin does not complement this defect. At the gene level, some alleles of R confer solid coloration on the aleurone layer when transmitted maternally but patchy coloration (mottled) when transmitted via pollen. In contrast with the endosperm, no effect of parentage on R phenotype has been detected in embryonic and seedling tissues. Furthermore, gynogenetic and androgenetic haploid plants are viable in maize and are similar in appearance. The detection of parental effects in the endosperm, but not the embryo, points to the few cell divisions of the gametophytes as a critical stage in imprinting. Chromosomally based epigenetic variation originating at this stage would be reflected as imprinting effects. A separate fertilization establishes a line of genetic descent in the embryo that appears to be relatively free of imprinted genes.
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Mullakaev, Orazali, Minsagit Lutfullin, Evgeny Kirillov, Elena Zaikina, and Gulnar Nizamova. "Effect of the drug “Degelm-14” on spontaneously infected chickens with eimeriosis." BIO Web of Conferences 52 (2022): 00042. http://dx.doi.org/10.1051/bioconf/20225200042.
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The studies show that when using the preparation "Degelm-14" after infection of birds, the histological structure in most of the studied organs was gradually restored. In the glandular stomach and small intestine on the 22nd day after application of the studied preparation the microstructure of the organ recovered completely. Microstructural changes in the cloacal pouch and spleen after application of Degelm-14 indicated restoration of the proliferative activity of the cells of the germinal centers. In the liver, at the final stage of the study, there were no signs of metabolic disorders in hepatocytes, and the dark pink coloration of their cytoplasm indicated an increase in synthetic processes in the cells of the organ parenchyma. But in the kidneys there were still observed signs of impaired glomerular filtration, regulating the function of the organ.
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Arellano-Aguilar, Omar, and Constantino Macías Garcia. "Exposure to pesticides impairs the expression of fish ornaments reducing the availability of attractive males." Proceedings of the Royal Society B: Biological Sciences 275, no. 1640 (March 18, 2008): 1343–51. http://dx.doi.org/10.1098/rspb.2008.0163.
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Ornament magnitude often reflects a local balance between sexual selection and other sources of natural selection opposing their elaboration. Human activity may disrupt this balance if it modifies the costs of producing, maintaining or displaying the ornaments. When costs are increased, a shortage of acceptable partners may ensue, with consequences commensurate with how stringent (and effective) the process of mate choice is. Here, we show that the expression of ornaments in the viviparous amarillo fish ( Girardinichthys multiradiatus ) is influenced by embryonic exposure to low concentrations of an organophosphorus insecticide. Male ornamental fin size, dimorphic yellow coloration and display rates were all compromised in exposed fish, but unaffected in their paternal half-sibling controls and in their sisters (morphology and colour). Exposure resulted in smaller fish of both sexes, thus the differential effect by sex was restricted to attributes such as fin size only above the naturally selected magnitude shown by females. Father phenotype predicted offspring morphology of controls, but not of exposed males, which were discriminated against by both control and exposed females. Since stringent female mate choice can result in females refusing to mate with suboptimal mates, this sub-lethal developmental effect can reduce the effective population size of amarillo fish populations.
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Si, Si, Xiao Xu, Yan Zhuang, Xiaodong Gao, Honghai Zhang, Zhengting Zou, and Shu-Jin Luo. "The genetics and evolution of eye color in domestic pigeons (Columba livia)." PLOS Genetics 17, no. 8 (August 30, 2021): e1009770. http://dx.doi.org/10.1371/journal.pgen.1009770.
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The eye color of birds, generally referring to the color of the iris, results from both pigmentation and structural coloration. Avian iris colors exhibit striking interspecific and intraspecific variations that correspond to unique evolutionary and ecological histories. Here, we identified the genetic basis of pearl (white) iris color in domestic pigeons (Columba livia) to explore the largely unknown genetic mechanism underlying the evolution of avian iris coloration. Using a genome-wide association study (GWAS) approach in 92 pigeons, we mapped the pearl iris trait to a 9 kb region containing the facilitative glucose transporter gene SLC2A11B. A nonsense mutation (W49X) leading to a premature stop codon in SLC2A11B was identified as the causal variant. Transcriptome analysis suggested that SLC2A11B loss of function may downregulate the xanthophore-differentiation gene CSF1R and the key pteridine biosynthesis gene GCH1, thus resulting in the pearl iris phenotype. Coalescence and phylogenetic analyses indicated that the mutation originated approximately 5,400 years ago, coinciding with the onset of pigeon domestication, while positive selection was likely associated with artificial breeding. Within Aves, potentially impaired SLC2A11B was found in six species from six distinct lineages, four of which associated with their signature brown or blue eyes and lack of pteridine. Analysis of vertebrate SLC2A11B orthologs revealed relaxed selection in the avian clade, consistent with the scenario that during and after avian divergence from the reptilian ancestor, the SLC2A11B-involved development of dermal chromatophores likely degenerated in the presence of feather coverage. Our findings provide new insight into the mechanism of avian iris color variations and the evolution of pigmentation in vertebrates.
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Oliveira, Sueyde F. de, Denis S. da Costa, Simone da C. Mello, Ana Dionisia da LC Novembre, and Francisco G. Gomes-Junior. "Germination of parsley seeds influenced by mericarps color and internal morphology." Horticultura Brasileira 31, no. 2 (June 2013): 231–35. http://dx.doi.org/10.1590/s0102-05362013000200009.
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The objective of the present study was to establish a relationship between mericarps color and internal morphology of parsley with the germination, using sorting by coloration and the X-ray test. The completely randomized design was used, with four replications per treatment. The treatments were constituted of four lots (A, B, C and D) and three mericarps colors (green, yellow and black) in 4×3 factorial experiment. The mericarps were exposed to X-ray test (60s; 20kV), being used the digital equipment Faxitron X-ray, model MX-20 DC12 and then, the irradiated mericarps were submitted to the germination test. The yellow mericarps showed higher germination and speed germination index. The green mericarps showed deformations and impaired formation of embryo, while black and yellow mericarps showed up without deformation and with a well-formed embryo. We concluded that there is a relationship between parsley seed germination and mericarps color. Poorly formed embryos and misshapened seed coats are related to green mericarps.
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Leiva-Ampuero, Andrés, Mario Agurto, José Tomás Matus, Gustavo Hoppe, Camila Huidobro, Claudio Inostroza-Blancheteau, Marjorie Reyes-Díaz, Claudia Stange, Paulo Canessa, and Andrea Vega. "Salinity impairs photosynthetic capacity and enhances carotenoid-related gene expression and biosynthesis in tomato (Solanum lycopersicum L. cv. Micro-Tom)." PeerJ 8 (September 17, 2020): e9742. http://dx.doi.org/10.7717/peerj.9742.
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Carotenoids are essential components of the photosynthetic antenna and reaction center complexes, being also responsible for antioxidant defense, coloration, and many other functions in multiple plant tissues. In tomato, salinity negatively affects the development of vegetative organs and productivity, but according to previous studies it might also increase fruit color and taste, improving its quality, which is a current agricultural challenge. The fruit quality parameters that are increased by salinity are cultivar-specific and include carotenoid, sugar, and organic acid contents. However, the relationship between vegetative and reproductive organs and response to salinity is still poorly understood. Considering this, Solanum lycopersicum cv. Micro-Tom plants were grown in the absence of salt supplementation as well as with increasing concentrations of NaCl for 14 weeks, evaluating plant performance from vegetative to reproductive stages. In response to salinity, plants showed a significant reduction in net photosynthesis, stomatal conductance, PSII quantum yield, and electron transport rate, in addition to an increase in non-photochemical quenching. In line with these responses the number of tomato clusters decreased, and smaller fruits with higher soluble solids content were obtained. Mature-green fruits also displayed a salt-dependent higher induction in the expression of PSY1, PDS, ZDS, and LYCB, key genes of the carotenoid biosynthesis pathway, in correlation with increased lycopene, lutein, β-carotene, and violaxanthin levels. These results suggest a key relationship between photosynthetic plant response and yield, involving impaired photosynthetic capacity, increased carotenoid-related gene expression, and carotenoid biosynthesis.
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Rowe, Melissah, Gábor Árpád Czirják, Kevin J. McGraw, and Mathieu Giraudeau. "Sexual ornamentation reflects antibacterial activity of ejaculates in mallards." Biology Letters 7, no. 5 (April 13, 2011): 740–42. http://dx.doi.org/10.1098/rsbl.2011.0276.
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Bacteria present in ejaculates can impair sperm function and reduce male reproductive success. Thus, selection should favour the evolution of antimicrobial defences to limit the detrimental effects of sperm-associated bacteria. Additionally, current hypotheses suggest that ornamental traits may signal information about the infection status of an individual or the ability of an individual to resist bacterial-induced sperm damage. However, despite the evolutionary implications of ejaculate antimicrobials, and the putative importance of pathogens for the evolution of male ornamentation, tests of these hypotheses are lacking. We examined the antibacterial activity of semen from mallard ducks ( Anas platyrhynchos ) and tested whether the bactericidal capacity of semen was associated with bill coloration, a sexually selected trait. We show that mallard semen exhibits significant antibacterial activity, as measured by the in vitro capacity to kill Escherichia coli and Staphylococcus aureus . Furthermore, we demonstrate that males with more colourful bills have semen with superior bacterial-killing ability. These results suggest that females could use male phenotypic traits to avoid sexually transmitted pathogens and acquire partners whose sperm suffer less bacteria-induced damage.
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Fan, Yan-Gen, Ting-Ting Zhao, Qin-Zeng Xiang, Xiao-Yang Han, Shu-Sen Yang, Li-Xia Zhang, and Li-Jun Ren. "Multi-Omics Research Accelerates the Clarification of the Formation Mechanism and the Influence of Leaf Color Variation in Tea (Camellia sinensis) Plants." Plants 13, no. 3 (January 31, 2024): 426. http://dx.doi.org/10.3390/plants13030426.
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Tea is a popular beverage with characteristic functional and flavor qualities, known to be rich in bioactive metabolites such as tea polyphenols and theanine. Recently, tea varieties with variations in leaf color have been widely used in agriculture production due to their potential advantages in terms of tea quality. Numerous studies have used genome, transcriptome, metabolome, proteome, and lipidome methods to uncover the causes of leaf color variations and investigate their impacts on the accumulation of crucial bioactive metabolites in tea plants. Through a comprehensive review of various omics investigations, we note that decreased expression levels of critical genes in the biosynthesis of chlorophyll and carotenoids, activated chlorophyll degradation, and an impaired photosynthetic chain function are related to the chlorina phenotype in tea plants. For purple-leaf tea, increased expression levels of late biosynthetic genes in the flavonoid synthesis pathway and anthocyanin transport genes are the major and common causes of purple coloration. We have also summarized the influence of leaf color variation on amino acid, polyphenol, and lipid contents and put forward possible causes of these metabolic changes. Finally, this review further proposes the research demands in this field in the future.
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Chan, Sze Wa, and Brian Tomlinson. "Effects of Bilberry Supplementation on Metabolic and Cardiovascular Disease Risk." Molecules 25, no. 7 (April 3, 2020): 1653. http://dx.doi.org/10.3390/molecules25071653.
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Metabolic syndrome is a cluster of interrelated conditions that is associated with an increased risk of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). Oxidative stress may impair normal physiological functions, leading to various illnesses. T2DM is considered to be associated with increased oxidative stress, inflammation, and dyslipidemia, which may play a significant role in the development of cardiovascular complications, cancer and vision loss through cataracts and retinopathy. While conventional therapies are a cornerstone for the management of the major risk factors of metabolic syndrome, increasing antioxidant defense by increasing intake of antioxidant-rich foods may improve long term prospects in CVD, obesity and T2DM. Bilberry (Vaccinium myrtillus L.) is one of the richest natural sources of anthocyanins which give berries their red/purple/blue coloration. Anthocyanins are powerful antioxidants and are reported to play an important role in the prevention of metabolic disease and CVD as well as cancer and other conditions. This review focuses on the potential effects of bilberry supplementation on metabolic and cardiovascular risk factors. Although there is evidence to support the use of bilberry supplementation as part of a healthy diet, the potential benefits from the use of bilberry supplementation in patients with T2DM or CVD needs to be clarified in large clinical trials.
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FL, Camara, Balde H, Barry AM, Camara SN, Diakite SY, Balde AK, Soromou G, et al. "Achalasia of the Esophagus at Donka National Hospital: A Case Report." Journal of Medical Research and Surgery 4, no. 4 (July 18, 2023): 70–72. http://dx.doi.org/10.52916/jmrs234111.
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Background: Esophageal achalasia is an esophageal motility disorder of unknown etiology that results in impaired lower esophageal sphincter relaxation and loss of esophageal peristalsis. The aim of our study was to show our experience in the management of esophageal achalasia in a case treated by laparotomy in our service. Case Report: 21-year-old patient, student, admitted to our department for progressive dysphagia to solids accompanied by regurgitation, epigastric pain, nocturnal cough and weight loss, evolving for 5 years. ATCD of pulmonary tuberculosis. The physical examination noted a deterioration in general condition, stage (I) of the WHO; there was hypo coloration of the integuments and conjunctivae, TA=120/80mmHg, Pulse=70/min. The abdomen was symmetrical with presence of sluggish skin folds, supple and painless without a palpable mass, the digital rectal examination did not present any particularity. The thorax was symmetrical with a FR=20 c/mn. The biology showed a normo chrome and normocytic anemia of 8 g/l Group O+. The esogastroduodenal transit was in favor of an amputation (tight stenosis) extended on the cardia with megaesophagus upstream. We performed a cardiomyotomy according to Heller associated with a hemivalve according to Toupet. We performed a followed by preesophageal and subhepatic drainage. The postoperative course was simple, marked by a resumption of food on D6 postoperatively. The control test carried out with gastrographine 10 days after the surgical intervention noted a regression of the signs with passage of the product of contrast in the small intestine. The patient seen again 6 months after the operation showed no particularities. Conclusion: Achalasia is a chronic esophageal motility disorder characterized by the inability of the lower esophageal sphincter to relax. Heller cardiomyotomy by laparotomy associated with Toupet-type fundoplication retains its place in its management in our exercise context.
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Dinalli, Raíssa Pereira, Salatiér Buzetti, Rodolfo de Niro Gazola, Regina Maria Monteiro de Castilho, Arshad Jalal, Fernando Shintate Galindo, and Marcelo Carvalho Minhoto Teixeira Filho. "Nitrogen Fertilization and Glyphosate as a Growth Regulator: Effects on the Nutritional Efficiency and Nutrient Balance in Emerald Grass." Agronomy 12, no. 10 (October 11, 2022): 2473. http://dx.doi.org/10.3390/agronomy12102473.
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Nitrogen (N) is one of the promising nutrients for lawn growth and is required for the lawn’s proper growth and development, but it also increases mowing frequency. Glyphosate herbicide application in sub-doses, as a growth regulator, can reduce the maintenance costs without any adverse reduction in the density and nutritional status of grasses. The objective of this study was to evaluate the influences of nitrogen and glyphosate doses on the growth, aesthetic quality and nutritional status of emerald grass (Zoysia japonica Steud.). The experiment was conducted at the Research and Extension Education Farm of São Paulo State University (UNESP), Ilha Solteira, SP, Brazil, in an Ultisol. The experiment was designed as a randomized block with 12 treatments arranged in a 3 × 4 factorial scheme with 4 replications, comprised of a control (without N), 15 and 30 g N m−2 of urea, applied in five splits annually, and glyphosate doses (0, 200, 400 and 600 g ha−1 of the active ingredient, a.i.). The split N fertilization at the rate of 15 g m−2 and glyphosate at the dose of 400 g ha−1 maintained nutritional status of emerald grass. Nitrogen at the rate 15 g N m−2 (in five splits per year) was observed to produce lower growth traits, an adequate aesthetic quality and longer stability of the nutrients in emerald grasses through lower exportation, with removal of “clipping” after mowing. In addition, glyphosate, at the dose of 400 g a.i. ha−1, was efficient in reducing the leaf area, plant height, shoot dry matter and total dry matter by 18.3, 14.7, 6.8 and 8.1%, respectively, as compared to the control. However, this dose did not impair the coloration and resulted in a lower exportation of nutrients by reducing the need to replenish by fertilization. Therefore, fertilization with 15 g N m−2, associated with application of 400 g a.i. ha−1 of glyphosate, is recommended for emerald grass in the tropical savannah of Brazil.
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Megía-Palma, Rodrigo, Santiago Merino, and Rafael Barrientos. "Longitudinal effects of habitat quality, body condition, and parasites on colour patches of a multiornamented lizard." Behavioral Ecology and Sociobiology 76, no. 6 (May 23, 2022). http://dx.doi.org/10.1007/s00265-022-03182-w.
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Abstract Ontogeny is expected to be a determinant factor affecting production of colour patches in lizards, while immune challenges or sudden weight loss may impair the maintenance of pigment-based coloration within a breeding season. We translocated males of the lizard Psammodromus algirus between two sampling plots that differed in distance to a road, vegetation structure, and predator abundance. We analysed variation in spectral reflectance of their colour patches the same and the following year. The change in the reflectance of the lizard colour patches within the first breeding season was explained by the interaction between plot and treatment, but not body condition. The maintenance of the breeding coloration was impaired only in those males translocated close to the road, probably reflecting that it is a poor-quality habitat for P. algirus. The following year, lizards that produced a more elaborate coloration were those that increased their body condition and controlled some parasitic infections, although suffered an increase of others. This study shows that colour patch production is plastic in P. algirus. Lizards increasing parasites or losing weight reduced pigmentation, although habitat quality can cushion these negative effects on pigmentation. However, not all parasites constrain the investment in coloration. In fact, some increased in those lizards that allocated more pigments to colour patches. In conclusion, longitudinal studies following experimental manipulation can contribute to understand pigment allocation rules in lizards. Significance statement Pigments involved in colour patches of animals are limiting resources that can be reallocated off the skin to other functions. However, longitudinal evidence of this phenomenon is scarce in reptiles. We designed a manipulative mark-recapture experiment to investigate effects of habitat and parasitic infections on colour patch maintenance (within-year variation) and production (between-year variation) in male free-ranging lizards that were reciprocally translocated between two patches of habitat that differed in quality. During the first year, lizards translocated to the habitat with more predators and worse vegetation impoverished their coloration, while lizards translocated to the more favourable habitat maintained it despite all translocated lizards loose body condition. The next year we detected different effects on the coloration of three different parasites investigated, suggesting that coloration can reflect the virulence of the infections.
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Kawaguchi, Yuri, Koyo Nakamura, Masaki Tomonaga, and Ikuma Adachi. "Impairment effect of infantile coloration on face discrimination in chimpanzees." Royal Society Open Science 8, no. 11 (November 2021). http://dx.doi.org/10.1098/rsos.211421.
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Impaired face recognition for certain face categories, such as faces of other species or other age class faces, is known in both humans and non-human primates. A previous study found that it is more difficult for chimpanzees to differentiate infant faces than adult faces. Infant faces of chimpanzees differ from adult faces in shape and colour, but the latter is especially a salient cue for chimpanzees. Therefore, impaired face differentiation of infant faces may be due to a specific colour. In the present study, we investigated which feature of infant faces has a greater effect on face identification difficulty. Adult chimpanzees were tested using a matching-to-sample task with four types of face stimuli whose shape and colour were manipulated as either infant or adult one independently. Chimpanzees' discrimination performance decreased as they matched faces with infant coloration, regardless of the shape. This study is the first to demonstrate the impairment effect of infantile coloration on face recognition in non-human primates, suggesting that the face recognition strategies of humans and chimpanzees overlap as both species show proficient face recognition for certain face colours.
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Stiefenhofer, Georg. "Hearing aid delay in open-fit devices – coloration-pitch discrimination in normal-hearing and hearing-impaired." International Journal of Audiology, March 17, 2022, 1–9. http://dx.doi.org/10.1080/14992027.2022.2049380.
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Fernández-Eslava, Blanca, Alejandro Cantarero, Daniel Alonso, and Carlos Alonso-Alvarez. "Wild common crossbills produce redder body feathers when their wings are clipped." BMC Zoology 7, no. 1 (August 23, 2022). http://dx.doi.org/10.1186/s40850-022-00150-9.
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Abstract Background The animal signaling theory posits that conspicuous colorations exhibited by many animals have evolved as reliable signals of individual quality. Red carotenoid-based ornaments may depend on enzymatic transformations (oxidation) of dietary yellow carotenoids, which could occur in the inner mitochondrial membrane (IMM). Thus, carotenoid ketolation and cell respiration could share the same biochemical pathways. Accordingly, the level of trait expression (redness) would directly reveal the efficiency of individuals’ metabolism and, hence, the bearer quality in an unfalsifiable way. Different avian studies have described that the flying effort may induce oxidative stress. A redox metabolism modified during the flight could thus influence the carotenoid conversion rate and, ultimately, animal coloration. Here, we aimed to infer the link between red carotenoid-based ornament expression and flight metabolism by increasing flying effort in wild male common crossbills Loxia curvirostra (Linnaeus). In this order, 295 adult males were captured with mist nets in an Iberian population during winter. Approximately half of the birds were experimentally handicapped through wing feather clipping to increase their flying effort, the other half being used as a control group. To stimulate the plumage regrown of a small surface during a short time-lapse, we also plucked the rump feathers from all the birds. Results A fraction of the birds with fully grown rump feathers (34 individuals) could be recaptured during the subsequent weeks. We did not detect any significant bias in recovery rates and morphological variables in this reduced subsample. However, among recaptured birds, individuals with experimentally impaired flying capacity showed body mass loss, whereas controls showed a trend to increase their weight. Moreover, clipped males showed redder feathers in the newly regrown rump area compared to controls. Conclusions The results suggest that wing-clipped individuals could have endured higher energy expenditure as they lost body mass. Despite the small sample size, the difference in plumage redness between the two experimental groups would support the hypothesis that the flying metabolism may influence the redox enzymatic reactions required for converting yellow dietary carotenoids to red ketocarotenoids.
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Alabd, Ahmed, Mudassar Ahmad, Xiao Zhang, Yuhao Gao, Lin Peng, Lu Zhang, Junbei Ni, Songling Bai, and Yuanwen Teng. "Light-responsive transcription factor PpWRKY44 induces anthocyanin accumulation by regulating PpMYB10 expression in pear." Horticulture Research, September 6, 2022. http://dx.doi.org/10.1093/hr/uhac199.
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Abstract Anthocyanins are a valuable source of antioxidants in the human diet and contribute to fruit coloration. In red-skinned pears, anthocyanin biosynthesis can be induced by light, in which the MYB–bHLH–WDR complex plays a critically important role in transcriptional regulation. However, the knowledge of WRKY-mediated transcriptional regulation of light-induced anthocyanin biosynthesis is scarce in red pears. This work identified and functionally characterized a light-inducing WRKY TF, PpWRKY44, in pear. Functional analysis based on overexpressed pear calli showed that PpWRKY44 promoted anthocyanin accumulation. Also, transiently overexpressed PpWRKY44 in pear leaves and fruit peels significantly enhanced the accumulation of anthocyanin, whereas silencing PpWRKY44 in pear fruit peels impaired induction of the accumulation of anthocyanin by light. By chromatin immunoprecipitation and electrophoretic mobility shift assay coupled to a quantitative polymerase chain reaction, we found that PpWRKY44 bound in-vivo and in-vitro to the PpMYB10 promoter, revealing it as a direct downstream target gene. Moreover, PpWRKY44 was activated by PpBBX18, a light signal transduction pathway component. Our results explained the mechanism mediating the impacts of PpWRKY44 on the transcriptional regulation of anthocyanin accumulation, with potential implications for fine-tuning the fruit peel coloration triggered by light in red pears.
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Shinohara, Yukari, Satoshi Kasagi, Noriko Amiya, Yukihiro Hoshino, Ryo Ishii, Noriyuki Hyodo, Hiroaki Yamaguchi, et al. "Taisho-Sanshoku koi have hardly faded skin and show attenuated melanophore sensitivity to adrenaline and melanin-concentrating hormone." Frontiers in Endocrinology 13 (December 22, 2022). http://dx.doi.org/10.3389/fendo.2022.994060.
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IntroductionKoi carp, an ornamental fish derived from the common carp Cyprinus carpio (CC), is characterized by beautiful skin color patterns. However, the mechanism that gives rise to the characteristic vivid skin coloration of koi carp has not been clarified. The skin coloration of many teleosts changes in response to differences in the background color. This change in skin coloration is caused by diffusion or aggregation of pigment granules in chromatophores and is regulated mainly by sympathetic nerves and hormones. We hypothesized that there would be some abnormality in the mechanism of skin color regulation in koi carp, which impairs skin color fading in response to background color.MethodsWe compared the function of melanin-concentrating hormone (MCH), noradrenaline, and adrenaline in CC and Taisho-Sanshoku (TS), a variety of tri-colored koi.Results and DiscussionIn CC acclimated to a white background, the skin color became paler and pigment granules aggregated in melanophores in the scales compared to that in black-acclimated CC. There were no clear differences in skin color or pigment granule aggregation in white- or black-acclimated TS. The expression of mch1 mRNA in the brain was higher in the white-acclimated CC than that in the black-acclimated CC. However, the expression of mch1 mRNA in the brain in the TS did not change in response to the background color. Additionally, plasma MCH levels did not differ between white- and black-acclimated fish in either CC or TS. In vitro experiments showed that noradrenaline induced pigment aggregation in scale melanophores in both CC and TS, whereas adrenaline induced pigment aggregation in the CC but not in the TS. In vitro administration of MCH induced pigment granule aggregation in the CC but not in the TS. However, intraperitoneal injection of MCH resulted in pigment granule aggregation in both CC and TS. Collectively, these results suggest that the weak sensitivity of scale melanophores to MCH and adrenaline might be responsible for the lack of skin color change in response to background color in the TS.
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Ma, Yang-Yang, Jian-Cheng Shi, Dan-Juan Wang, Xia Liang, Feng Wei, Chun-Mei Gong, Li-Juan Qiu, et al. "A point mutation in the gene encoding Mg-chelatase subunit I influences strawberry leaf color and metabolism." Plant Physiology, April 22, 2023. http://dx.doi.org/10.1093/plphys/kiad247.
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Abstract Magnesium chelatase catalyzes the insertion of magnesium into protoporphyrin IX, a vital step in chlorophyll biogenesis. The enzyme consists of three subunits, (Magnesium chelatase I subunit, CHLI), (Magnesium chelatase D subunit, CHLD) and (Magnesium chelatase H subunit, CHLH). The CHLI subunit is an ATPase that mediates catalysis. Previous studies on CHLI have mainly focused on model plant species, and its functions in other species have not been well described, especially with regard to leaf coloration and metabolism. In this study, we identified and characterized a CHLI mutant in strawberry species Fragaria pentaphylla. The mutant, noted as p240, exhibits yellow-green leaves and a low chlorophyll (Chl) level. RNA-seq identified a mutation in the 186th amino acid of the CHLI subunit, a base conserved in most photosynthetic organisms. Transient transformation of wild-type CHLI into p240 leaves complemented the mutant phenotype. Further mutants generated from RNA-interference (RNAi) and CRISPR/Cas9 gene editing recapitulated the mutant phenotype. Notably, heterozygous chli mutants accumulated more chlorophyll under low light conditions compared to high light conditions. Metabolite analysis of null mutants under high light conditions revealed substantial changes in both nitrogen and carbon metabolism. Further analysis indicated that mutation in Glu186 of CHLI does not affect its subcellular localization, nor the interaction between CHLI and CHLD. However, intramolecular interactions were impaired, leading to reduced ATPase and magnesium chelatase activity. These findings demonstrate that Glu186 plays a key role in enzyme function, affecting leaf coloration via the formation of the hexameric ring itself, and that manipulation of CHLI may be a means to improve strawberry plant fitness and photosynthetic efficiency under low light conditions.
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Nunes Junior, Donaldo Antônio, Heder José D’Avila Lima, Jean Kaique Valentim, Laura Aline Zanelatto Souza, Nayara Emanoelle Matos e. Silva, Ana Carolina da Silva Martins, Tatiana Marques Bittencourt, and Janaína Palermo Mendes. "Vegetable pigments in sorghum-based diets for laying hens." Caderno de Ciências Agrárias 12 (November 4, 2020). http://dx.doi.org/10.35699/2447-6218.2020.24309.
Full textAbstract:
The main objective of this research is to evaluate the inclusion of different natural pigment solutions in diets formulated with maize and sorghum solutions on the growth performance and egg quality of commercial laying hens created in hot climates. Throughout the conduction of this experiment, were used 252 laying hens of the Hisex Brow, in a completely randomized design, with six treatments, seven repetitions, and six birds per plot. The experimental diets were assigned with different energy sources and adding pigmentation solutions, diet 1 (corn), diet 2 (corn + annatto), diet 3 (corn + carrot), diet 4 (sorghum), diet 5 (sorghum + annatto), diet 6 (sorghum + Carrot). Afterward, being evaluated the performance and quality of eggs. It was observed significant difference with reference t egg production, egg weight (g), gem weight (g), the weight of shell (g), albumin in weight (g), and gem coloration (tons) among the treatments. There was no difference in the parameters of performance and quality of eggs evaluated, only the variable yolk color had a significant effect between treatments. Replacing the energy source of the corn diet with sorghum in the diet of laying hens at peak production provides similar performance and egg quality, which can be a substitute for quality and efficiency. The use of annatto and carrots as a natural pigmentation promotes greater pigmentation of the egg yolks of laying Hisex Brown eggs and does not impair the performance of the birds.
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Bryla, Amadeusz, Elisavet Zagkle, Edyta T. Sadowska, Mariusz Cichoń, and Ulf Bauchinger. "Measurements of body temperature and oxidative stress in plasma reveal differential costs associated with humoral immune function in a passerine bird." Journal of Experimental Biology, October 31, 2022. http://dx.doi.org/10.1242/jeb.244897.
Full textAbstract:
Eco-immunology considers resistance to antigens a costly trait for an organism, but actual quantification of such costs appears not straight forward. Costs of the immune response (IR) are e.g., visible in impaired coloration, reduced growth or reproductive success. Activation of the humoral IR is a slow, complex, and long-lasting process, which makes the quantification of its energetic cost a potential losing game. We implemented near continuous measurements of body temperature in zebra finches (Taeniopygia guttata) as a proxy for the energetic cost with particular interests in the body temperature from activation of the humoral IR until the peak of antibody release several days later. At the peak of the antibody release we additionally measured oxygen consumption (open-flow respirometry) and markers of oxidative stress (dROMs, OXY). Birds with activated IR defended a higher night time body temperature during the first four nights after an immune challenge in comparison to controls, implying increased night time energy use. At the peak of antibody production, we did not find differences in night time body temperature and oxygen consumption but observed a differentiated results for oxygen consumption during day time. Immune challenged females had significantly higher oxygen consumption than other groups. Moreover, we found that activation of the humoral IR increases oxidative damage, a potential cost of defending higher night time body temperature crucial at the early stage of the IR. The costs generated by the immune system appear to consist of two components energetic and non-energetic, and these may appear separated in time.
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Afifi, Maha, David Obenland, and Ashraf El-kereamy. "The Complexity of Modulating Anthocyanin Biosynthesis Pathway by Deficit Irrigation in Table Grapes." Frontiers in Plant Science 12 (August 18, 2021). http://dx.doi.org/10.3389/fpls.2021.713277.
Full textAbstract:
Deficit irrigation (DI) is an irrigation scheduling technique that is used in grapes to improve red color development; however, results are not always satisfactory in table grapes. The red color in grapes is mainly due to the plant pigment anthocyanin. In the present study, the anthocyanin biosynthesis in Scarlet Royal grapes (Vitis vinifera L.) grown in the San Joaquin and Coachella Valleys, and subjected to two different DI strategies was investigated. The objective of this study was to identify potential regulatory factors that may lead to potential treatments to improve red color in table grapes, especially under warm climate conditions. In both locations, DI induced the expression of several genes involved in three major pathways that control the red color in table grapes: anthocyanin biosynthesis, hormone biosynthesis, and antioxidant system. DI at veraison induced anthocyanin accumulation and enhanced red color in berries at harvest time. However, anthocyanin accumulation was lower at the Coachella Valley compared to the San Joaquin Valley. The lower level of anthocyanin was associated with lower expression of critical genes involved in anthocyanin biosynthesis, such as flavonoid-3-O-glucosyltransferase (UFGT), myb-related regulatory gene (R2R3-MYB) (MYBA1), basic helix-loop-helix (bHLH) (MYCA1) and the tryptophan-aspartic acid repeat (WDR or WD40) proteins (WDR1). Further, gene expression analysis revealed the association of ABA biosynthesis gene 9-cis-epoxycarotenoid dioxygenase (NCED1), 1-aminocyclopropane-1-carboxylic acid oxidase (ACO3), and the gibberellic acid (GA) catabolic gene GA2 oxidase (GA2ox1) in the induction of anthocyanin biosynthesis. An increase in the chalcone synthase gene (CHS2) was observed in response to DI treatments in both sites. However, CHS2 expression was higher in Coachella Valley after ending the DI treatment, suggesting the involvement of environmental stress in elevating its transcripts. This data was also supported by the lower level of antioxidant gene expression and enzyme activities in the Coachella Valley compared to the San Joaquin Valley. The present data suggested that the lack of grape red coloration could partially be due to the lower level of antioxidant activities resulting in accelerated anthocyanin degradation and impaired anthocyanin biosynthesis. It seems that under challenging warmer conditions, several factors are required to optimize anthocyanin accumulation via DI, including an active antioxidant system, proper light perception, and hormonal balance.