Two leaf color variants red-leaf(R-type)and common-leaf(G-type)of Euonymus sacrosancta Koidz.,were employed as experimental materials to elucidate the molecular mechanisms underlying chromatic transition.Physiological...Two leaf color variants red-leaf(R-type)and common-leaf(G-type)of Euonymus sacrosancta Koidz.,were employed as experimental materials to elucidate the molecular mechanisms underlying chromatic transition.Physiological profiling identified anthocyanins and flavo-noids as the predominant pigments responsible for the red foliar phenotype,which exhibited reduced chlorophyll and carotenoid accumulation but elevated soluble sugars and proteins.Comparative transcriptomic analysis revealed that differentially expressed genes(DEGs)between R-type and G-type were significantly enriched in flavonoid biosynthe-sis and carotenoid metabolism pathways.The up-regulation of 22 key genes of anthocyanin synthesis(e.g.,CHS,CHI,LAR,LDOX and UFGT)in R-type may lead to the phenotype of red leaves through the increase of anthocyanin accumula-tion.The downregulated expression of 13 carotenoid syn-thesis-related genes(e.g.,PSY,PDS and VDE)and 6 carot-enoid degradation genes(e.g.,ABA2,CYP707A and NCED)may lead to lower carotenoid content in R-type compared to G-type.Combined with weighted gene co-expression network analysis(WGCNA),five candidate genes(EsLAR,EsLDOX,EsPDS,EsCYP707A and EsABA2)were screened from two modules highly correlated with anthocyanin con-tent in E.sacrosancta leaves.These genes may play key regulatory roles in leaf coloration and could serve as candi-date genetic resources for leaf color improvement in E.sac-rosancta.Additionally,transcription factors such as C2H2s,C3Hs,and WRKYs were identified as potential regulators in the formation of R-type in E.sacrosancta.This study pro-vides the first systematic elucidation of the transcriptional regulatory network governing red-leaf formation in E.sac-rosancta,establishing a critical theoretical foundation for molecular breeding in ornamental plants.展开更多
The color and pattern of watermelon rind are crucial external traits that directly affect consumer preferences.Watermelons with stripes having a stronger color than the background rind are ideal for studying stripe pa...The color and pattern of watermelon rind are crucial external traits that directly affect consumer preferences.Watermelons with stripes having a stronger color than the background rind are ideal for studying stripe patterns in plants,while there is still limited knowledge about the genetic mechanisms underlying stripe coloration due to the lack of germplasm resources.In this study,we focused on a watermelon germplasm with colorless stripes,and genetic analysis revealed that the trait is controlled by a single recessive gene.The gene Clsc(Citrullus lanatus stripe coloration),which is responsible for the colorless stripe,was localized into a 147.6 kb region on Chr9 by linkage analysis in a large F2 mapping population.Further analysis revealed that the Cla97C09G175170 gene encodes the APRR2 transcription factor,plays a crucial role in determining the watermelon colorless stripe phenotype and was deduced to be related to chlorophyll synthesis and chloroplast development.Physiological experiments indicated that Cla97C09G175170 may significantly influence chloroplast development and chlorophyll synthesis in watermelon.The results of this study provide a better understanding of the molecular mechanism of stripe coloration in watermelon and can be useful in the development of marker-assisted selection(MAS)for new watermelon cultivars.展开更多
Sexual selection is thought to play a major role in the evolution of color due to the correlation between a signaler’s physiological state and the displayed color.As such,researchers often investigate how color corre...Sexual selection is thought to play a major role in the evolution of color due to the correlation between a signaler’s physiological state and the displayed color.As such,researchers often investigate how color correlates to the quality of the signaler.However,research on the relationship between color and individual quality is often taxonomically limited and researchers typically investigate how color phenotypes relate to one index of quality,such as a linear measure of body size.Here,we investigated the relationship among body size,claw size,claw muscle mass,lipid content,and the color of the claw in male fiddler crabs(Leptuca uruguayensis)which wield an exaggerated claw that varies in color from brown to red.We hypothesized that if the color was correlated to one or more indices of male quality,the color displayed on the claws of male L.uruguayensis could be under sexual selection.We found L.uruguayensis claw color varies substantially among the individuals we photographed.However,we did not find a correlation between claw color and indices of quality;neither brightness nor hue correlated to the indices of quality we measured.Our findings suggest that claw color in L.uruguayensis is unlikely to have evolved to signal quality,but may instead function as a species identity or as a non-indicator sexual signal.展开更多
While the functions of body coloration have been well characterized in many animal taxa,the molecular mechanisms governing its production remain poorly understood.This study investigated the genetic and biochemical ba...While the functions of body coloration have been well characterized in many animal taxa,the molecular mechanisms governing its production remain poorly understood.This study investigated the genetic and biochemical basis of yellow body coloration in a mutant form of the Yongzhang golden soft-shelled turtle(YGT,Pelodiscus sinensis),which exhibit a striking yellow phenotype.Comparative pigment analysis revealed that YGTs have significantly lower melanin and higher carotenoid pigmentation compared to atrovirens wild-type turtles(AWTs),while pterin concentrations did not differ between the two groups.Functional validation experiments demonstrated that a single amino acid substitution(I481R)in tyrosinase-related protein 1(tyrp1)plays a pivotal role in the reduction of melanin production in YGTs.Expression of tyrp1 from YGTs and AWTs in A375 cells,in which human tyrp1(htyrp1)function was depleted by CRISPR-Cas9,led to a specific reduction in melanin production in cells expressing the YGT-tyrp1 variant.Moreover,bco1 and bco2,genes negatively associated with carotenoid content,showed reduced expression in YGTs,suggesting that yellow coloration is achieved through a reduction in melanin pigmentation combined with an accumulation of carotenoids.These findings elucidate the molecular basis of yellow body coloration in turtles and enhance our understanding of pigment regulation in vertebrates.展开更多
Acer paxii belongs to the evergreen species of Acer,but it exhibits a unique feature of reddish leaves in fall in subtropical regions.Although the association of AP2/ERF transcription factors with color change has bee...Acer paxii belongs to the evergreen species of Acer,but it exhibits a unique feature of reddish leaves in fall in subtropical regions.Although the association of AP2/ERF transcription factors with color change has been well-documented in prior research,molecular investigations focusing on AP2/ERF remain notably lacking in Acer paxii.This research focuses on performing an extensive genome-wide investigation to identify and characterize the AP2/ERF gene family in Acer paxii.As a result,123 ApAP2/ERFs were obtained.Phylogenetic analyses categorized the ApAP2/ERF family members into 15 subfamilies.The evolutionary traits of the ApAP2/ERFs were investigated by analyzing their chromosomal locations,conserved proteinmotifs,and gene duplication events.Moreover,investigating gene promoters revealed their potential involvement in developmental regulation,physiological processes,and stress adaptationmechanisms.Measurements of anthocyanin content revealed a notable increase in red leaves during autumn.Utilizing transcriptome data,transcriptomic profiling revealed that the majority of AP2/ERF genes in Acer paxii displayed significant differential expression between red and green leaves during the color-changing period.Furthermore,through qRT-PCR analysis,it was found that the gene expression levels of ApERF006,ApERF014,ApERF048,ApERF097,and ApERF107 were significantly elevated in red leaves.This indicates their potential participation in leaf pigmentation processes.These findings offer significant insights into the biological significance of ApAP2/ERF transcription factors and lay the groundwork for subsequent investigations into their regulatorymechanisms underlying leaf pigmentation in Acer paxii.展开更多
Animal species exhibit a wide range of coloration and patterns,which are under strong selection and often linked to individual quality,influencing mate choice,recognition,signaling,and interspecific interactions such ...Animal species exhibit a wide range of coloration and patterns,which are under strong selection and often linked to individual quality,influencing mate choice,recognition,signaling,and interspecific interactions such as predator avoidance.In amphibians,coloration can vary based on individual traits as well as environmental conditions,including the coloration of their environment.In this study,we described the dorsal coloration(body coloration reticulated by dark patches)in 676 Western spadefoot toads(Pelobates cultripes)from the French Atlantic coast,comparing color variations across different substrates.In addition,we assessed color change in 18 toads transferred between bright and dark substrates.We demonstrated that the dorsal coloration varies based on capture locations(beach vs.inland)and associated substrate types(bright vs.dark),suggesting background color matching.We showed more pronounced effects in females,which might reflect varying predation risks.Experimentally,we showed that individuals can rapidly adjust their coloration to match the substrate within 24 h.Rapid color changes in response to substrate type indicate significant pigmentation plasticity.Bright individuals from sandy substrates showed less dorsal background(body)color change than dark inland individuals,while patch coloration responded differently depending on the substrate of origin.These findings highlight the complex interactions between substrate type,sex,and pigmentation plasticity.These interactions have potential costs and benefits,which might be linked to melanin production,which warrant further investigation.展开更多
Animal coloration has a wide range of biological functions and may be subject to different,sometimes conficting,selective pressures.In crustaceans,the evolution of coloration is relatively unstudied,despite the broad ...Animal coloration has a wide range of biological functions and may be subject to different,sometimes conficting,selective pressures.In crustaceans,the evolution of coloration is relatively unstudied,despite the broad range of colors and color patterns,which includes variability at multiple levels.Freshwater crayfsh are known to show color variability within species and populations,as well as intra-individual variability,but thefunction,if any,of crayfsh coloration is largely unknown.Here,I report on an experiment to understand patterns of color variability in the crayfsh Faxonius virilis and show that variation is strongly correlated to ontogenetic changes from a summer non-reproductive form to a fall reproductiveform.Crayfsh showed comparatively little inter-and intra-individual color variation in their non-reproductive form,but substantial variation at bothlevels in the reproductive form.Transition to the reproductive form was associated with the development of greener or bluer coloration localizedto the chelae on a subset of individuals,but these changes showed no clear correlation with sex or body size.Future investigations should focuson determining whether differences in color between individuals in the mating season are associated with any physiological or behavioral differences,or with differential susceptibility to predation.展开更多
Localized manipulation of light interference and phase through surface microstructures provides new viable technologies for applications such as anti-counterfeiting,camouflage,high-density optical storage and display....Localized manipulation of light interference and phase through surface microstructures provides new viable technologies for applications such as anti-counterfeiting,camouflage,high-density optical storage and display.However,the single-color rendering mechanism and the material’s intrinsic properties,such as hydrophilicity,low hardness and low melting point,limit the range of applications.In this paper,we propose a structural color based on ultrathin ZrO_(2)thin films,which presents a visible full-spectrum color display.The structural color coating has ultrahigh flame retardancy,super UV resistance,super surface hardness and resistance to acid and alkali corrosion.The use of two different color development mechanisms realizes the hiding of the quick response(QR)code in visible light.The modified film exhibits superhydrophobic properties,unique anti-icing and self-cleaning properties,and shows the material’s potential for camouflage,anti-counterfeiting,military,marine and aerospace applications.展开更多
Female cichlid fish living in African great lakes are known to have sensory systems that are adapted to ambient light environments.These sen-sory system adaptations are hypothesized to have influenced the evolution of...Female cichlid fish living in African great lakes are known to have sensory systems that are adapted to ambient light environments.These sen-sory system adaptations are hypothesized to have influenced the evolution of the diverse male nuptial coloration.In rock-dwelling Lake Malawi mbuna cichlids,however,the extent to which ambient light environments influence female sensory systems and potentially associated male nuptial coloration remains unknown.Yet,the ubiquitous blue flank coloration and UV reflection of male mbuna cichlids suggest the potential impacts of the blue-shifted ambient light environment on these cichlid's visual perception and male nuptial coloration in the shallow water depth in Lake Malawi.In the present study,we explored whether and how the sensory bias of females influences intersexual communication in the mbuna cichlid,Metriaclima zebra.A series of choice experiments in various light environments showed that M.zebra females (1)have a pref-erence for the blue-shifted light environment,(2)prefer to interact with males in blue-shifted light environments,(3)do not show a preference between dominant and subordinate males in full-spectrum,long-wavelength filtered,and short-wavelength filtered light environments,and (4)show a"reversed"preference for subordinate males in the UV-filtered light environment.These results suggest that the visual perception of M.zebra females may be biased to the ambient light spectra in their natural habitat by local adaptation and that this sensory bias may influence the evolution of blueand UV reflectivepatterns in male nuptial coloration.展开更多
The first record of abnormal body coloration in Sebastes koreanus Kim and Lee,1994,from the Yellow Sea of China,was documented based on morphological characteristics and DNA barcoding.The two rockfish specimens were c...The first record of abnormal body coloration in Sebastes koreanus Kim and Lee,1994,from the Yellow Sea of China,was documented based on morphological characteristics and DNA barcoding.The two rockfish specimens were collected from the coastal waters of Qingdao,China,and the whole body and all fins of them were red.Of the two red-colored rockfish,there were tiny deep red spots on each fin,2 red radial stripes behind and below the eyes and 1 large deep red blotch on the opercula,while the similar stripe and spot patterns are also present in the S.koreanus specimens with normal body coloration.The countable characteristics of the two specimens are in the range of the morphometry of S.koreanus.To further clarify the species identity and taxonomic status of the two specimens,DNA barcode analysis was carried out.The genetic distance between the red-colored rockfish and S.koreanus was 0,and the minimum net genetic distances between the red-colored rockfish and other Sebastes species except for S.koreanus were 3.0%,which exceeds the threshold of species delimitation.The phylogenetic analysis showed that the DNA barcoding sequences of the two red-colored rockfish clustered with the S.koreanus sequences.The above results of DNA barcode analysis also support that the two red-colored rockfish could be identified as the species of S.koreanus.The mechanism of color variation in S.koreanus is desirable for further research and the species could be an ideal model to study the color-driven speciation of the rockfishes.展开更多
Anthocyanins play crucial roles in pollen protection and pollinator attraction in flowering plants.However,the mechanisms underlying flower color determination and whether floral anthocyanin regulators participate in ...Anthocyanins play crucial roles in pollen protection and pollinator attraction in flowering plants.However,the mechanisms underlying flower color determination and whether floral anthocyanin regulators participate in other processes remain largely unresolved in soybeans(Glycine max).In this study,we investigated the genetic components and mechanisms governing anthocyanin biosynthesis in soybean flowers.Molecular and genetic studies have characterized two antagonistic regulators,the positive activator GmMYBA3 and the negative repressor GmMYBR1,that modulate the gene expression of anthocyanin biosynthesis in soybean flowers.Further findings revealed a regulatory interplay between GmMYBA3 and GmMYBR1 bridged by GmTT8a,highlighting the complexity of anthocyanin regulation in different soybean organs.Exploration of additional soybean cultivars demonstrated the universality of GmMYBA3 and GmMYBR1 in regulating floral anthocyanin biosynthesis-related genes,with GmF3’5’H identified as a crucial determinant of white flower color.This study provides a molecular mechanism underlying soybean flower color determination,paving the way for the molecular modification of soybean flowers to probably enhance their resistance to abiotic stresses and attractiveness to pollinators.展开更多
Taking the six common anthocyanidins in nature, i.e. cyanidin, delphinidin, malvidin, pelargonidin, peonidin and petunidin, as examples, this paper summarized the main achievements about the structure-activity relatio...Taking the six common anthocyanidins in nature, i.e. cyanidin, delphinidin, malvidin, pelargonidin, peonidin and petunidin, as examples, this paper summarized the main achievements about the structure-activity relationships of the coloration and stability of anthocyanidins. The coloration and stability of anthocyanidins are funda- mentally determined by the chemical and spatial structures of the anthocyanidins. The electron-deficient state, hydroxylation and methylation patterns, especially the ones on the B-ring, and coplanarity of the three rings of anthocyanidins are inde- pendently or synergetically, positively and/or negatively, influence the coloration and stability of the anthocyanidins. Thereinto, the in vivo colorations of anthocyanins are also related to the organ-selective and crystal- or anthocyanic vacuolar inclusion- related existence of the anthocyanidins. This review could provide a reference for the researches of the structure-optimizing and function-exploiting of anthocyanidins and also for the selection of the crops and cultivars containing specific anthocyani- din profiles.展开更多
Carotenoids, which generate yellow, orange, and red colors, are crucial pigments in avian plumage. Investigations into genes associated with carotenoid- based coloration in avian species are important; however, such r...Carotenoids, which generate yellow, orange, and red colors, are crucial pigments in avian plumage. Investigations into genes associated with carotenoid- based coloration in avian species are important; however, such research is difficult because carotenoids cannot be synthetized in vertebrates as they are only derived from dietary sources. Here, the golden pheasant （Chrysolophus pictus） was used as a model in analysis of candidate gene expression profiles implicated in carotenoid binding and deposition. Using mass and Raman spectrometry to confirm the presence of carotenoids in golden pheasant feathers, we found C40H540 and C40H5602 in feathers with yellow to red colors, and in the rachis of iridescent feathers. The global gene expression profiles in golden pheasant skins were analyzed by RNA-seq and all six carotenoid binding candidate genes sequenced were studied by real- time PCR. STAR4, GSTA2, Scarbl, and APOD in feather follicles showed different expressions in red breast and orange nape feathers compared with that of iridescent mantle feathers. Further comparison of golden pheasant yellow rump and Lady Amherst＇s pheasant （Chrysolophus amherstiae） white nape feathers suggested that GSTA2 and APOD played a potential role in carotenoid-based coloration in golden pheasant.展开更多
Autumn leaf senescence and coloration is a complex process and a striking natural phenomenon.Here,through biology approach integrating transcriptomic analyses in Ginkgo biloba,we determined that the content of chlorop...Autumn leaf senescence and coloration is a complex process and a striking natural phenomenon.Here,through biology approach integrating transcriptomic analyses in Ginkgo biloba,we determined that the content of chlorophyll decreased during leaf senescence,while carotenoid components increased until late October in the turning stage(TS)and then decreased in the yellow leaf stage(YS).Simultaneously,chlorophyll biosynthesis genes exhibited significantly lower expression levels while chlorophyll degradation genes showed increased expression from the green leaf stage(GS)to YS.However,carotenoid biosynthesis-related genes showed enhanced expression,especially in TS.An analysis of the expression of genes related to senescence demonstrated that the expression levels of most abscisic acid-and jasmonic acid-related genes,autophagy,WRKY,and NAC genes increased,whereas cytoskeleton-,photosynthesis-,and antioxidation-related genes decreased from GS to YS.Furthermore,G.biloba seedlings exogenously treated with abscisic acid,jasmonic acid,or ultraviolet-B radiation all showed obvious color variation and senescence symptoms.We used these exogenously seedlings to further validate the function of several genes involved in chlorophyll biosynthesis and senescence.Taken together,these results contribute to the elucidation of the molecular mechanisms of leaf coloration and senescence in G.biloba as well as in the identification of candidate genes involved in this process.展开更多
The fruit peel color is a crucial trait of cucumber.To better understand the molecular mechanisms underlying cucumber peel coloration,we compared the UPLC-ESI-MS/MS-based flavonoid metabolomic and RNA sequencing-based...The fruit peel color is a crucial trait of cucumber.To better understand the molecular mechanisms underlying cucumber peel coloration,we compared the UPLC-ESI-MS/MS-based flavonoid metabolomic and RNA sequencing-based transcriptomic profiling of the brown peeled cucumber line‘PW’at six developmental stages.A total of 210 flavonoid metabolites were identified.Of which,117 flavonoid metabolites were differentially accumulated.In this study,weighted gene co-expression network analysis combined with Kyoto Encyclopedia of Gene and Genomes enrichment analysis revealed key genes coding for seven enzymes and eight transcription factors(TFs)associated with flavonoid biosynthesis.Among them,the R2R3MYB CsaV3_4G001130 is the best candidate gene that is responsible for controlling mature fruit colors in cucumber.Sanger sequencing revealed one nonsynonymous SNP in the exon of CsaV3_4G001130 among the selected 11 cucumber lines,which introduced a premature stop codon,generating a truncated protein in pale yellow or creamy peeled fruits.Yeast two-hybrid assays showed a direct interaction of CsaV3_4G001130 with the bHLH TF CsaV3_1G002260 and the WD40 protein CsaV3_5G001800.However,the interactions were influenced by the nonsynonymous SNP we identified.Our finding revealed that the integrated transcriptome and metabolome analysis further demonstrated that the abundance of some pigmented flavonoids(especially anthocyanins and chalcones)contributed to the coloration of‘PW’fruits.These findings pave the way for elucidation of flavonoid biosynthesis and improvement of cucumber peel color in the future.展开更多
Molluscan shell color has received persistent attention for its distinctive diversity and complexity. In the present study, six transcriptome libraries obtained from two developmental stages, pre-pigmentation and post...Molluscan shell color has received persistent attention for its distinctive diversity and complexity. In the present study, six transcriptome libraries obtained from two developmental stages, pre-pigmentation and post-pigmentation, were used for paired-end sequencing in the bay scallop Argopecten irradians. In total, 289 839 646 paired-end reads were assembled into 70 929 transcripts. Using BLASTX and BLASTN, 30 896 unigenes were successfully annotated against the SWISS-PROT, NR, and KOG database. Gene ontology annotation and Kyoto Encyclopedia of Genes and Genomes classification identified numbers of unigenes involved in biomineralization and pigmentation. Digital gene expression analysis revealed that melanin, trace metal elements and porphyrins are potentially involved in shell coloration of A. irradians.展开更多
Despite growing interest in female ornament evolution, we still have a rudimentary understanding of female display traits relative to similar traits in males. Under one popular adaptive scenario, female ornaments are ...Despite growing interest in female ornament evolution, we still have a rudimentary understanding of female display traits relative to similar traits in males. Under one popular adaptive scenario, female ornaments are hypothesized to function in female-female competition and serve as badges of status, such that their expression is linked with elevated aggression in some cases. In this study, we investigated the relationship between 2 female ornaments--male-like red throat color and red spine coloration--and female aggression in 2 independently derived stream-resident populations of three-spined stickleback Gasterosteus aculeatus. Using simulated intrusions, we tested whether females with redder ornaments were generally more aggressive, and for variation in aggressive and social behaviors between the 2 populations. We found that the red intensity of the throat and spine did not predict aggression levels in either population, suggesting a limited role for both female ornaments during female-female interaction. The 2 populations exhibited different levels of aggressive behaviors, unrelated to the color patches. Our results suggest that variation in selective pressures between populations may promote interpopulation variance in aggressive behavior but not the correlation between female ornamentation and aggression, and raise the possibility that red coloration may have evolved through different mechanisms or processes in the 2 populations.展开更多
Sexual selection often leads to evolution of conspicuous signals,raising the chances of attracting not only potential mates,but also predators.In lacertid lizards,ultraviolet(UV)-blue spots on flanks and shoulders rep...Sexual selection often leads to evolution of conspicuous signals,raising the chances of attracting not only potential mates,but also predators.In lacertid lizards,ultraviolet(UV)-blue spots on flanks and shoulders represent such a trait.Some level of correlation between male and female ornamen-tation is also known to exist.Therefore,the phenotype of females may change in the absence of sexual selection.We tested this hypothesis on a complex of parthenogenetic and bisexual lizards of the genus Darevskia.We evaluated area,counts,and chromatic properties(UV opponency,sat-uration)of UV-blue spots and compared the values between the clones and their bisexual progeni-tor species.We found a fair heterogeneity between the parthenogenetic species,but no general tendency toward higher crypsis or conspicuousness.Values of the parthenogens were not signifi-cantly different from the values of sexual females.A possible explanation is that the changes in se-lective forces associated with parthenogenetic reproduction are too small to affect the resulting pattern of selective pressures on the studied traits,or that the phenotypes of the parthenogens re-sult from the unique combination of parental genomes and are conserved by clonal reproduction.展开更多
Tsavorite green colored by Cr3+/V3+ has been traditionally found and mined in Tanzania, Kenya and Madagascar in the Neoproterozoic Mozambique metamorphic belt (NMMB), and recently be found in Sanjiang, Litang, Sichuan...Tsavorite green colored by Cr3+/V3+ has been traditionally found and mined in Tanzania, Kenya and Madagascar in the Neoproterozoic Mozambique metamorphic belt (NMMB), and recently be found in Sanjiang, Litang, Sichuan, China. The differences of the chemical formula, spectroscopic features, as well as the concentrations of the V2O3 and Cr2O3 in the tsavorite crystals collected from major international deposits and Sanjiang, China have been investigated using EPMA, XRF, UV-VIS spectrometers, FTIR, Raman scattering microscopy, DiamondView TM techniques. It was found that the chemical formulas of African tsavorite and Chinese tsavorite are Ca3(Al,V)2[SiO4]3 and Ca3(Al,Cr)2[SiO4]3, respectively, indicating that tsavorite is a solid solution between dominant grossular and minor goldmanite and uvarovite. Two broad bands centered at 430 nm and 605 nm were the main absorption features in the tsavorite samples, which attribute to the absorption of Cr3+ and/or V3+ ions in the lattice. The green coloration is caused by Cr3+ and/or V3+ ions resulting in the absorption of purple and red components of the visible light. Absorptions caused of Fe3+ and Fe2+ ions could add the bluish color component in some of tsavorite samples. The intensity of green color is proportional to the concentrations of V2O3 and Cr2O3. The basic gemological properties, such as refractive index in the investigated samples were presented, and the definition and chemical and spectroscopic properties of tsavorite are discussed.展开更多
N-pivot lariat ethers with picrylamino group as a chromophore (1, 2 and 3) have been prepared by reaction of N-(4-aminoaryl)monoaza crown ethers with picryl chrolide, and the selective coloration of 1, 2 and 3 for alk...N-pivot lariat ethers with picrylamino group as a chromophore (1, 2 and 3) have been prepared by reaction of N-(4-aminoaryl)monoaza crown ethers with picryl chrolide, and the selective coloration of 1, 2 and 3 for alkali metal salts and amines has been studied by UV-Vis spectra.展开更多
基金supported by the National Natural Science Foundation of China(No.32171738)the National Key Research and Development Program of China(No.2021YFD2200304)the Fundamental Research Funds for the Central Universities(No.2572022DQ08).
文摘Two leaf color variants red-leaf(R-type)and common-leaf(G-type)of Euonymus sacrosancta Koidz.,were employed as experimental materials to elucidate the molecular mechanisms underlying chromatic transition.Physiological profiling identified anthocyanins and flavo-noids as the predominant pigments responsible for the red foliar phenotype,which exhibited reduced chlorophyll and carotenoid accumulation but elevated soluble sugars and proteins.Comparative transcriptomic analysis revealed that differentially expressed genes(DEGs)between R-type and G-type were significantly enriched in flavonoid biosynthe-sis and carotenoid metabolism pathways.The up-regulation of 22 key genes of anthocyanin synthesis(e.g.,CHS,CHI,LAR,LDOX and UFGT)in R-type may lead to the phenotype of red leaves through the increase of anthocyanin accumula-tion.The downregulated expression of 13 carotenoid syn-thesis-related genes(e.g.,PSY,PDS and VDE)and 6 carot-enoid degradation genes(e.g.,ABA2,CYP707A and NCED)may lead to lower carotenoid content in R-type compared to G-type.Combined with weighted gene co-expression network analysis(WGCNA),five candidate genes(EsLAR,EsLDOX,EsPDS,EsCYP707A and EsABA2)were screened from two modules highly correlated with anthocyanin con-tent in E.sacrosancta leaves.These genes may play key regulatory roles in leaf coloration and could serve as candi-date genetic resources for leaf color improvement in E.sac-rosancta.Additionally,transcription factors such as C2H2s,C3Hs,and WRKYs were identified as potential regulators in the formation of R-type in E.sacrosancta.This study pro-vides the first systematic elucidation of the transcriptional regulatory network governing red-leaf formation in E.sac-rosancta,establishing a critical theoretical foundation for molecular breeding in ornamental plants.
基金supported by grants from theKey Scientific and Technological Project of Henan Province,China(222102110124)the Joint Fund of Science and Technology Research and Development Plan,Henan Province,China(222103810009)+4 种基金the National Natural Science Foundation of China(32172574,3217180560)the Funding of Joint Research on Agricultural Varieties Improvement of Henan Province,China(2022010503)the Major Science and Technology Project of Henan Province,China(221100110400)the Natural Science Foundation of Henan,China(222300420050)the Science and Technology Innovation Talent Support Program of Henan Province,China(23HASTIT034).
文摘The color and pattern of watermelon rind are crucial external traits that directly affect consumer preferences.Watermelons with stripes having a stronger color than the background rind are ideal for studying stripe patterns in plants,while there is still limited knowledge about the genetic mechanisms underlying stripe coloration due to the lack of germplasm resources.In this study,we focused on a watermelon germplasm with colorless stripes,and genetic analysis revealed that the trait is controlled by a single recessive gene.The gene Clsc(Citrullus lanatus stripe coloration),which is responsible for the colorless stripe,was localized into a 147.6 kb region on Chr9 by linkage analysis in a large F2 mapping population.Further analysis revealed that the Cla97C09G175170 gene encodes the APRR2 transcription factor,plays a crucial role in determining the watermelon colorless stripe phenotype and was deduced to be related to chlorophyll synthesis and chloroplast development.Physiological experiments indicated that Cla97C09G175170 may significantly influence chloroplast development and chlorophyll synthesis in watermelon.The results of this study provide a better understanding of the molecular mechanism of stripe coloration in watermelon and can be useful in the development of marker-assisted selection(MAS)for new watermelon cultivars.
基金funded by Fundacao de Amparoà Pesquisa do Estado de Sao Paulo(process no:2016/22679-3)funded through an undergraduate student scholarship for scientific research provided by Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq,process no:144202/2018-2).
文摘Sexual selection is thought to play a major role in the evolution of color due to the correlation between a signaler’s physiological state and the displayed color.As such,researchers often investigate how color correlates to the quality of the signaler.However,research on the relationship between color and individual quality is often taxonomically limited and researchers typically investigate how color phenotypes relate to one index of quality,such as a linear measure of body size.Here,we investigated the relationship among body size,claw size,claw muscle mass,lipid content,and the color of the claw in male fiddler crabs(Leptuca uruguayensis)which wield an exaggerated claw that varies in color from brown to red.We hypothesized that if the color was correlated to one or more indices of male quality,the color displayed on the claws of male L.uruguayensis could be under sexual selection.We found L.uruguayensis claw color varies substantially among the individuals we photographed.However,we did not find a correlation between claw color and indices of quality;neither brightness nor hue correlated to the indices of quality we measured.Our findings suggest that claw color in L.uruguayensis is unlikely to have evolved to signal quality,but may instead function as a species identity or as a non-indicator sexual signal.
基金supported by the National Natural Science Foundation of China(32030013)Project of Hebei Agricultural Innovation Team of Freshwater Aquaculture(HBCT2023230204)。
文摘While the functions of body coloration have been well characterized in many animal taxa,the molecular mechanisms governing its production remain poorly understood.This study investigated the genetic and biochemical basis of yellow body coloration in a mutant form of the Yongzhang golden soft-shelled turtle(YGT,Pelodiscus sinensis),which exhibit a striking yellow phenotype.Comparative pigment analysis revealed that YGTs have significantly lower melanin and higher carotenoid pigmentation compared to atrovirens wild-type turtles(AWTs),while pterin concentrations did not differ between the two groups.Functional validation experiments demonstrated that a single amino acid substitution(I481R)in tyrosinase-related protein 1(tyrp1)plays a pivotal role in the reduction of melanin production in YGTs.Expression of tyrp1 from YGTs and AWTs in A375 cells,in which human tyrp1(htyrp1)function was depleted by CRISPR-Cas9,led to a specific reduction in melanin production in cells expressing the YGT-tyrp1 variant.Moreover,bco1 and bco2,genes negatively associated with carotenoid content,showed reduced expression in YGTs,suggesting that yellow coloration is achieved through a reduction in melanin pigmentation combined with an accumulation of carotenoids.These findings elucidate the molecular basis of yellow body coloration in turtles and enhance our understanding of pigment regulation in vertebrates.
基金supported by the National Natural Science Foundation of China[grant numbers 32271914 and 32301660]the Quality Engineering Project of Anhui Provincial Department of Education[grant number 2023zygzts007].
文摘Acer paxii belongs to the evergreen species of Acer,but it exhibits a unique feature of reddish leaves in fall in subtropical regions.Although the association of AP2/ERF transcription factors with color change has been well-documented in prior research,molecular investigations focusing on AP2/ERF remain notably lacking in Acer paxii.This research focuses on performing an extensive genome-wide investigation to identify and characterize the AP2/ERF gene family in Acer paxii.As a result,123 ApAP2/ERFs were obtained.Phylogenetic analyses categorized the ApAP2/ERF family members into 15 subfamilies.The evolutionary traits of the ApAP2/ERFs were investigated by analyzing their chromosomal locations,conserved proteinmotifs,and gene duplication events.Moreover,investigating gene promoters revealed their potential involvement in developmental regulation,physiological processes,and stress adaptationmechanisms.Measurements of anthocyanin content revealed a notable increase in red leaves during autumn.Utilizing transcriptome data,transcriptomic profiling revealed that the majority of AP2/ERF genes in Acer paxii displayed significant differential expression between red and green leaves during the color-changing period.Furthermore,through qRT-PCR analysis,it was found that the gene expression levels of ApERF006,ApERF014,ApERF048,ApERF097,and ApERF107 were significantly elevated in red leaves.This indicates their potential participation in leaf pigmentation processes.These findings offer significant insights into the biological significance of ApAP2/ERF transcription factors and lay the groundwork for subsequent investigations into their regulatorymechanisms underlying leaf pigmentation in Acer paxii.
基金Funding was provided by the CNRS,La Rochelle Université,the LPO,the Agence de l’Eau Adour-Garonne,the Conseil Départemental de la Charente-Maritime,the ANR PAMPAS(ANR-18-CE32-0006)the Beauval Nature association,the Contrat de plan Etat-région Econat and the Région Nouvelle Aquitaine(Projet d’Observatoire du Marais de Brouage-PSGAR CRNA 2025).
文摘Animal species exhibit a wide range of coloration and patterns,which are under strong selection and often linked to individual quality,influencing mate choice,recognition,signaling,and interspecific interactions such as predator avoidance.In amphibians,coloration can vary based on individual traits as well as environmental conditions,including the coloration of their environment.In this study,we described the dorsal coloration(body coloration reticulated by dark patches)in 676 Western spadefoot toads(Pelobates cultripes)from the French Atlantic coast,comparing color variations across different substrates.In addition,we assessed color change in 18 toads transferred between bright and dark substrates.We demonstrated that the dorsal coloration varies based on capture locations(beach vs.inland)and associated substrate types(bright vs.dark),suggesting background color matching.We showed more pronounced effects in females,which might reflect varying predation risks.Experimentally,we showed that individuals can rapidly adjust their coloration to match the substrate within 24 h.Rapid color changes in response to substrate type indicate significant pigmentation plasticity.Bright individuals from sandy substrates showed less dorsal background(body)color change than dark inland individuals,while patch coloration responded differently depending on the substrate of origin.These findings highlight the complex interactions between substrate type,sex,and pigmentation plasticity.These interactions have potential costs and benefits,which might be linked to melanin production,which warrant further investigation.
文摘Animal coloration has a wide range of biological functions and may be subject to different,sometimes conficting,selective pressures.In crustaceans,the evolution of coloration is relatively unstudied,despite the broad range of colors and color patterns,which includes variability at multiple levels.Freshwater crayfsh are known to show color variability within species and populations,as well as intra-individual variability,but thefunction,if any,of crayfsh coloration is largely unknown.Here,I report on an experiment to understand patterns of color variability in the crayfsh Faxonius virilis and show that variation is strongly correlated to ontogenetic changes from a summer non-reproductive form to a fall reproductiveform.Crayfsh showed comparatively little inter-and intra-individual color variation in their non-reproductive form,but substantial variation at bothlevels in the reproductive form.Transition to the reproductive form was associated with the development of greener or bluer coloration localizedto the chelae on a subset of individuals,but these changes showed no clear correlation with sex or body size.Future investigations should focuson determining whether differences in color between individuals in the mating season are associated with any physiological or behavioral differences,or with differential susceptibility to predation.
基金supported by the National Key Research and Development Program of China(No.2021YFA1401100)the National Natural Science Foundation of China(Nos.61825403 and 61921005).
文摘Localized manipulation of light interference and phase through surface microstructures provides new viable technologies for applications such as anti-counterfeiting,camouflage,high-density optical storage and display.However,the single-color rendering mechanism and the material’s intrinsic properties,such as hydrophilicity,low hardness and low melting point,limit the range of applications.In this paper,we propose a structural color based on ultrathin ZrO_(2)thin films,which presents a visible full-spectrum color display.The structural color coating has ultrahigh flame retardancy,super UV resistance,super surface hardness and resistance to acid and alkali corrosion.The use of two different color development mechanisms realizes the hiding of the quick response(QR)code in visible light.The modified film exhibits superhydrophobic properties,unique anti-icing and self-cleaning properties,and shows the material’s potential for camouflage,anti-counterfeiting,military,marine and aerospace applications.
文摘Female cichlid fish living in African great lakes are known to have sensory systems that are adapted to ambient light environments.These sen-sory system adaptations are hypothesized to have influenced the evolution of the diverse male nuptial coloration.In rock-dwelling Lake Malawi mbuna cichlids,however,the extent to which ambient light environments influence female sensory systems and potentially associated male nuptial coloration remains unknown.Yet,the ubiquitous blue flank coloration and UV reflection of male mbuna cichlids suggest the potential impacts of the blue-shifted ambient light environment on these cichlid's visual perception and male nuptial coloration in the shallow water depth in Lake Malawi.In the present study,we explored whether and how the sensory bias of females influences intersexual communication in the mbuna cichlid,Metriaclima zebra.A series of choice experiments in various light environments showed that M.zebra females (1)have a pref-erence for the blue-shifted light environment,(2)prefer to interact with males in blue-shifted light environments,(3)do not show a preference between dominant and subordinate males in full-spectrum,long-wavelength filtered,and short-wavelength filtered light environments,and (4)show a"reversed"preference for subordinate males in the UV-filtered light environment.These results suggest that the visual perception of M.zebra females may be biased to the ambient light spectra in their natural habitat by local adaptation and that this sensory bias may influence the evolution of blueand UV reflectivepatterns in male nuptial coloration.
基金Supported by the National Key R&D Program of China (No.2018YFD0900803)the China Agriculture Research System of MOF and MARA (No.CARS-47)the Central Public-Interest Scientific Institution Basal Research Fund (Nos.2021JC01,20603022022024)
文摘The first record of abnormal body coloration in Sebastes koreanus Kim and Lee,1994,from the Yellow Sea of China,was documented based on morphological characteristics and DNA barcoding.The two rockfish specimens were collected from the coastal waters of Qingdao,China,and the whole body and all fins of them were red.Of the two red-colored rockfish,there were tiny deep red spots on each fin,2 red radial stripes behind and below the eyes and 1 large deep red blotch on the opercula,while the similar stripe and spot patterns are also present in the S.koreanus specimens with normal body coloration.The countable characteristics of the two specimens are in the range of the morphometry of S.koreanus.To further clarify the species identity and taxonomic status of the two specimens,DNA barcode analysis was carried out.The genetic distance between the red-colored rockfish and S.koreanus was 0,and the minimum net genetic distances between the red-colored rockfish and other Sebastes species except for S.koreanus were 3.0%,which exceeds the threshold of species delimitation.The phylogenetic analysis showed that the DNA barcoding sequences of the two red-colored rockfish clustered with the S.koreanus sequences.The above results of DNA barcode analysis also support that the two red-colored rockfish could be identified as the species of S.koreanus.The mechanism of color variation in S.koreanus is desirable for further research and the species could be an ideal model to study the color-driven speciation of the rockfishes.
基金supported by the National Natural Science Foundation of China(32201781,32100211)the Department of Science and Technology of Jilin Province(20220508112RC,20210101005JC)+1 种基金the Fundamental Research Fund for the Central Universities(2412023YQ005)China Agriculture Research System(CARS04)。
文摘Anthocyanins play crucial roles in pollen protection and pollinator attraction in flowering plants.However,the mechanisms underlying flower color determination and whether floral anthocyanin regulators participate in other processes remain largely unresolved in soybeans(Glycine max).In this study,we investigated the genetic components and mechanisms governing anthocyanin biosynthesis in soybean flowers.Molecular and genetic studies have characterized two antagonistic regulators,the positive activator GmMYBA3 and the negative repressor GmMYBR1,that modulate the gene expression of anthocyanin biosynthesis in soybean flowers.Further findings revealed a regulatory interplay between GmMYBA3 and GmMYBR1 bridged by GmTT8a,highlighting the complexity of anthocyanin regulation in different soybean organs.Exploration of additional soybean cultivars demonstrated the universality of GmMYBA3 and GmMYBR1 in regulating floral anthocyanin biosynthesis-related genes,with GmF3’5’H identified as a crucial determinant of white flower color.This study provides a molecular mechanism underlying soybean flower color determination,paving the way for the molecular modification of soybean flowers to probably enhance their resistance to abiotic stresses and attractiveness to pollinators.
基金Supported by the National Natural Science Foundation of China(31060045,31260091)~~
文摘Taking the six common anthocyanidins in nature, i.e. cyanidin, delphinidin, malvidin, pelargonidin, peonidin and petunidin, as examples, this paper summarized the main achievements about the structure-activity relationships of the coloration and stability of anthocyanidins. The coloration and stability of anthocyanidins are funda- mentally determined by the chemical and spatial structures of the anthocyanidins. The electron-deficient state, hydroxylation and methylation patterns, especially the ones on the B-ring, and coplanarity of the three rings of anthocyanidins are inde- pendently or synergetically, positively and/or negatively, influence the coloration and stability of the anthocyanidins. Thereinto, the in vivo colorations of anthocyanins are also related to the organ-selective and crystal- or anthocyanic vacuolar inclusion- related existence of the anthocyanidins. This review could provide a reference for the researches of the structure-optimizing and function-exploiting of anthocyanidins and also for the selection of the crops and cultivars containing specific anthocyani- din profiles.
基金supported by the 2014 Fundamental Research Program from Science and Technology of the Inner Mongolia Autonomous Region of China
文摘Carotenoids, which generate yellow, orange, and red colors, are crucial pigments in avian plumage. Investigations into genes associated with carotenoid- based coloration in avian species are important; however, such research is difficult because carotenoids cannot be synthetized in vertebrates as they are only derived from dietary sources. Here, the golden pheasant （Chrysolophus pictus） was used as a model in analysis of candidate gene expression profiles implicated in carotenoid binding and deposition. Using mass and Raman spectrometry to confirm the presence of carotenoids in golden pheasant feathers, we found C40H540 and C40H5602 in feathers with yellow to red colors, and in the rachis of iridescent feathers. The global gene expression profiles in golden pheasant skins were analyzed by RNA-seq and all six carotenoid binding candidate genes sequenced were studied by real- time PCR. STAR4, GSTA2, Scarbl, and APOD in feather follicles showed different expressions in red breast and orange nape feathers compared with that of iridescent mantle feathers. Further comparison of golden pheasant yellow rump and Lady Amherst＇s pheasant （Chrysolophus amherstiae） white nape feathers suggested that GSTA2 and APOD played a potential role in carotenoid-based coloration in golden pheasant.
基金This work was supported financially by National Key R&D Program of China(Grant No.2017YFD0600701)Natural Science Foundation of China(Grant No.31670181)+1 种基金Six talent peaks project in Jiangsu Province(Grant No.NY-090)Qing Lan Project of Jiangsu Province。
文摘Autumn leaf senescence and coloration is a complex process and a striking natural phenomenon.Here,through biology approach integrating transcriptomic analyses in Ginkgo biloba,we determined that the content of chlorophyll decreased during leaf senescence,while carotenoid components increased until late October in the turning stage(TS)and then decreased in the yellow leaf stage(YS).Simultaneously,chlorophyll biosynthesis genes exhibited significantly lower expression levels while chlorophyll degradation genes showed increased expression from the green leaf stage(GS)to YS.However,carotenoid biosynthesis-related genes showed enhanced expression,especially in TS.An analysis of the expression of genes related to senescence demonstrated that the expression levels of most abscisic acid-and jasmonic acid-related genes,autophagy,WRKY,and NAC genes increased,whereas cytoskeleton-,photosynthesis-,and antioxidation-related genes decreased from GS to YS.Furthermore,G.biloba seedlings exogenously treated with abscisic acid,jasmonic acid,or ultraviolet-B radiation all showed obvious color variation and senescence symptoms.We used these exogenously seedlings to further validate the function of several genes involved in chlorophyll biosynthesis and senescence.Taken together,these results contribute to the elucidation of the molecular mechanisms of leaf coloration and senescence in G.biloba as well as in the identification of candidate genes involved in this process.
基金The‘JBGS’Project of Seed Industry Revitalization in Jiangsu Province[Grant No.JBGS(2021)018]the Jiangsu Agricultural Innovation of New Cultivars(Grant No.PZCZ201720)+2 种基金the Jiangsu Agriculture Science and Technology Innovation Fund[Grant No.CX(20)3103]the Open Project Program of Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement(Grant No.K2020030)the Open Project Program of Joint International Research Laboratory of Agriculture and Agri-Product Safety,the Ministry of Education of China(Grant No.JILAR-KF202001).
文摘The fruit peel color is a crucial trait of cucumber.To better understand the molecular mechanisms underlying cucumber peel coloration,we compared the UPLC-ESI-MS/MS-based flavonoid metabolomic and RNA sequencing-based transcriptomic profiling of the brown peeled cucumber line‘PW’at six developmental stages.A total of 210 flavonoid metabolites were identified.Of which,117 flavonoid metabolites were differentially accumulated.In this study,weighted gene co-expression network analysis combined with Kyoto Encyclopedia of Gene and Genomes enrichment analysis revealed key genes coding for seven enzymes and eight transcription factors(TFs)associated with flavonoid biosynthesis.Among them,the R2R3MYB CsaV3_4G001130 is the best candidate gene that is responsible for controlling mature fruit colors in cucumber.Sanger sequencing revealed one nonsynonymous SNP in the exon of CsaV3_4G001130 among the selected 11 cucumber lines,which introduced a premature stop codon,generating a truncated protein in pale yellow or creamy peeled fruits.Yeast two-hybrid assays showed a direct interaction of CsaV3_4G001130 with the bHLH TF CsaV3_1G002260 and the WD40 protein CsaV3_5G001800.However,the interactions were influenced by the nonsynonymous SNP we identified.Our finding revealed that the integrated transcriptome and metabolome analysis further demonstrated that the abundance of some pigmented flavonoids(especially anthocyanins and chalcones)contributed to the coloration of‘PW’fruits.These findings pave the way for elucidation of flavonoid biosynthesis and improvement of cucumber peel color in the future.
基金Supported by the China Agriculture Research System(No.CARS-49)the Science and Technology Service Network Initiative of Chinese Academy of Sciences
文摘Molluscan shell color has received persistent attention for its distinctive diversity and complexity. In the present study, six transcriptome libraries obtained from two developmental stages, pre-pigmentation and post-pigmentation, were used for paired-end sequencing in the bay scallop Argopecten irradians. In total, 289 839 646 paired-end reads were assembled into 70 929 transcripts. Using BLASTX and BLASTN, 30 896 unigenes were successfully annotated against the SWISS-PROT, NR, and KOG database. Gene ontology annotation and Kyoto Encyclopedia of Genes and Genomes classification identified numbers of unigenes involved in biomineralization and pigmentation. Digital gene expression analysis revealed that melanin, trace metal elements and porphyrins are potentially involved in shell coloration of A. irradians.
文摘Despite growing interest in female ornament evolution, we still have a rudimentary understanding of female display traits relative to similar traits in males. Under one popular adaptive scenario, female ornaments are hypothesized to function in female-female competition and serve as badges of status, such that their expression is linked with elevated aggression in some cases. In this study, we investigated the relationship between 2 female ornaments--male-like red throat color and red spine coloration--and female aggression in 2 independently derived stream-resident populations of three-spined stickleback Gasterosteus aculeatus. Using simulated intrusions, we tested whether females with redder ornaments were generally more aggressive, and for variation in aggressive and social behaviors between the 2 populations. We found that the red intensity of the throat and spine did not predict aggression levels in either population, suggesting a limited role for both female ornaments during female-female interaction. The 2 populations exhibited different levels of aggressive behaviors, unrelated to the color patches. Our results suggest that variation in selective pressures between populations may promote interpopulation variance in aggressive behavior but not the correlation between female ornamentation and aggression, and raise the possibility that red coloration may have evolved through different mechanisms or processes in the 2 populations.
文摘Sexual selection often leads to evolution of conspicuous signals,raising the chances of attracting not only potential mates,but also predators.In lacertid lizards,ultraviolet(UV)-blue spots on flanks and shoulders represent such a trait.Some level of correlation between male and female ornamen-tation is also known to exist.Therefore,the phenotype of females may change in the absence of sexual selection.We tested this hypothesis on a complex of parthenogenetic and bisexual lizards of the genus Darevskia.We evaluated area,counts,and chromatic properties(UV opponency,sat-uration)of UV-blue spots and compared the values between the clones and their bisexual progeni-tor species.We found a fair heterogeneity between the parthenogenetic species,but no general tendency toward higher crypsis or conspicuousness.Values of the parthenogens were not signifi-cantly different from the values of sexual females.A possible explanation is that the changes in se-lective forces associated with parthenogenetic reproduction are too small to affect the resulting pattern of selective pressures on the studied traits,or that the phenotypes of the parthenogens re-sult from the unique combination of parental genomes and are conserved by clonal reproduction.
文摘Tsavorite green colored by Cr3+/V3+ has been traditionally found and mined in Tanzania, Kenya and Madagascar in the Neoproterozoic Mozambique metamorphic belt (NMMB), and recently be found in Sanjiang, Litang, Sichuan, China. The differences of the chemical formula, spectroscopic features, as well as the concentrations of the V2O3 and Cr2O3 in the tsavorite crystals collected from major international deposits and Sanjiang, China have been investigated using EPMA, XRF, UV-VIS spectrometers, FTIR, Raman scattering microscopy, DiamondView TM techniques. It was found that the chemical formulas of African tsavorite and Chinese tsavorite are Ca3(Al,V)2[SiO4]3 and Ca3(Al,Cr)2[SiO4]3, respectively, indicating that tsavorite is a solid solution between dominant grossular and minor goldmanite and uvarovite. Two broad bands centered at 430 nm and 605 nm were the main absorption features in the tsavorite samples, which attribute to the absorption of Cr3+ and/or V3+ ions in the lattice. The green coloration is caused by Cr3+ and/or V3+ ions resulting in the absorption of purple and red components of the visible light. Absorptions caused of Fe3+ and Fe2+ ions could add the bluish color component in some of tsavorite samples. The intensity of green color is proportional to the concentrations of V2O3 and Cr2O3. The basic gemological properties, such as refractive index in the investigated samples were presented, and the definition and chemical and spectroscopic properties of tsavorite are discussed.
文摘N-pivot lariat ethers with picrylamino group as a chromophore (1, 2 and 3) have been prepared by reaction of N-(4-aminoaryl)monoaza crown ethers with picryl chrolide, and the selective coloration of 1, 2 and 3 for alkali metal salts and amines has been studied by UV-Vis spectra.
