pigment formation
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2021 ◽  
Vol 29 (1) ◽  
pp. 97-106
Author(s):  
Iman Rusmana ◽  
Yuni Puji Hastuti ◽  
Rizal Khoirun Alfisah ◽  
Alina Akhdiya

Certain strains of V. parahaemolyticus carry a gene that encodes a toxin that causes Acute hepatopancreatic necrosis disease (AHPND) in P. vannamei. AHPND attacks shrimp post larvae within 20-30 days after stocking causing up to 100% mortality. The expression of these virulent genes is controlled by the quorum sensing system. This system is inhibited by an anti-quorum sensing (AQS) mechanism. Several Bacillus strains have AQS mechanism by producing AHL-Lactonase enzyme. Therefore, this study aimed to obtain Bacillus spp. having AQS activity for controlling AHPND. The study was conducted from isolation and selection of Bacillus isolates, as well as determination of AQS activity. From 22 samples consisting of shrimp intestines, water and pond sediment samples, a total of 151 isolates of Bacillus spp. were isolated. The screening test for AQS activity obtained 11 isolates that showed AQS activity on Cromobacterium violaceum. Determination of violacein pigment in liquid cultures of C. violaceum showed the index value of the pigment formation was between 0.025-0.166 and 0.026-0.567 at 24-hour and between 48-hour incubations, respectively. The quantitative analysis of violacein production showed that there were six isolates of Bacillus could inhibit the pigment production more than 75%. The isolates were identified as Bacillus cereus (four isolates), Bacillus thuringiensis (one isolate), and Bacillus velezensis (one isolate), respectively. The molecular analysis had confirmed that the isolates have aiiA genes encoding AHL-lactonase enzyme. These Bacillus isolates have potential application for controlling AHNPD disease.


2021 ◽  
Vol 43 (3) ◽  
pp. 1529-1547
Author(s):  
Lixiong Peng ◽  
Jiang Chang ◽  
Xilin Liu ◽  
Shiying Lu ◽  
Honglin Ren ◽  
...  

Melanocortin 1 receptor (MC1R) is thought to be a marker of poor prognosis and a potential target for the treatment of melanoma. Studies have found that MC1R promotes several tumor behaviors, including cell proliferation and differentiation, pigment formation, and genome damage repair. Some single-nucleotide polymorphisms (SNPs) of MC1R are involved in the occurrence and development of melanoma. A few studies have reported a relationship between MC1R and colorectal cancer (CRC). In this research, our objective was to examine MC1R expression and MC1R SNPs and investigate their correlation with the clinicopathological features of human CRC tissues. We evaluated MC1R mRNA expression by performing bioinformatic analyses on human CRC expression datasets. We used Western blotting and RT-qPCR to compare MC1R expression in CRC tissues with that in normal tissues, and MC1R SNPs in CRC tissues were detected by PCR-direct sequencing (DS). The expression of MC1R was significantly decreased in CRC tissues compared with normal tissue, and its expression was negatively associated with P53 expression, MLH1 expression, and PMS2 expression, and high MC1R expression was significantly associated with microsatellite instability (MSI). MC1R SNPs were also associated with the clinicopathological characteristics of CRC; for example, the rs2228479 locus genotype was correlated with Ki67 status, and the rs885479 locus genotype was correlated with age and T stage. In conclusion, MC1R plays a crucial role in the progression of CRC and may be a marker of poor prognosis in CRC.


Author(s):  
Baodi Dai ◽  
Yinxing Xu ◽  
Hongyu Wu ◽  
Jiangye Chen

Abstract Candida albicans has long been known to switch between white and opaque phases; however, a third cell type, referred to as the ‘gray’ phenotype, was recently characterized. The three phenotypes have different colonial morphologies, with white cells forming white-colored colonies and opaque and gray cells forming dark-colored colonies. We previously showed that Wor1-upregulated ferroxidases (Fets) function as pigment multicopper oxidases that regulate the production of dark-pigmented melanin in opaque cells. In this study, we demonstrated that Fets also contributed to dark pigment formation in gray colonies but in a Wor1-independent manner. Deletion of both WOR1 and EFG1 locked cells in the gray phenotype in some rich media. However, the efg1/efg1 wor1/wor1 mutant could switch between white and gray in minimal media depending on the ambient pH. Specifically, mutant cells exhibited the white phenotype at pH 4.5 but switched to gray at pH 7.5. Consistent with phenotype switching, Fets expressions and melanin production were also regulated by ambient pH. Ectopic expression of the Rim101-405 allele in the mutant enabled the pH restriction to be bypassed and promoted gray cell formation in acidic media. Our data suggest that Rim101-upregulated Fets contribute to dark pigment formation in the gray cells.


2021 ◽  
pp. 39-45

The aim of this study is to synthesize, and study a new form of dye based on phthalocyanine, a silicon-containing phthalocyanine pigment used as a dye for dye-sensitive solar cells, which are currently third generation solar cells as one of the energy source alternatives. To achieve this goal, a silicon-containing phthalocyanine pigment containing urea, phthalic anhydride and sodium fluorosilicate was synthesized and studied. Based on the results of IR spectroscopy, the reaction of pigment formation is proposed and the data of scanning electron microscopy is presented. Its differential thermal analysis, photodynamic analysis and its relationship with inorganic and organic solvents were also analyzed. The optical density of the pigment was analyzed on a V-5000 spectrophotometer at wavelengths with a spectral with from 320 nm to 1000 nm. The study was carried out in 5% and 20% solutions of dimethylformamide. The absorption peaks showed good absorption at wavelengths from 400 to 500 nm. Derivatographic studies of the obtained pigment show that the main weight loss occurs in the range 110-482 °C, at which 18.25% of the basic weight, or 3.21 mg of weight, is lost, which means that the pigment is thermally stable.


2021 ◽  
Vol 21 (103) ◽  
pp. 18518-18532
Author(s):  
Norah Vhangani Lusani ◽  
◽  
L Mogashoa ◽  
J Van Wyk

The antioxidant and anti-browning activity of heated plant extracts have been attributed to the formation of Maillard reaction products (MRPs) via the Maillard reaction (MR). The inhibitory effect of heated Moringa oleifera (MO) seed extract on banana polyphenol oxidase (PPO) was investigated. The Plain MO seed extracts and those with added glucose and glycine (1.5 mM each) were heated at 100°C for 15, 30, 60 and 120 min. The pH and brown colour development decreased and increased significantly (P <0.05) with increased reaction time, respectively, with heated moringa glucose-glycine HMGGL for 120 min exhibiting the highest pH reduction (2.58) and darkest extracts at an L* value of 8.11. This phenomenon is associated with progression of the MR. With reference to enzymatic browning, heated MO seed extracts exhibited stronger inhibitory effect against banana PPO activity in vivo and in vitro than the unheated counterpart. Evident to this are the higher inhibition percentages and lower ΔE values. Among model systems, the highest in vitro browning inhibition was exhibited mostly by longer heating times of 60 and 120 min. Model system HMGGL 120 min proved to be superior at 96% inhibition, which was comparable to known synthetic commercial antioxidants such as ascorbic acid (AA) at 99%, as well as ethylenediaminetetraacetic acid (EDTA) and citric acid (CA), both at 100% inhibition. In vivo enzymatic browning inhibition followed a similar trend, where the brown pigment (melanin) intensified as shown by an increase in ΔE as the storage time increased from 0.5 to 24 h. The model system UMGGL exhibited highest inhibition of brown melanin (p <0.05). Although it was the best amongst other model systems, it was surpassed by synthetic antioxidants AA, EDTA and CA, which were ranked amongst the top three in inhibiting brown pigment formation in vivo. To further illustrate the effect of MR augmented MO seed extracts on enzyme activity inhibition, UMGGL 60 and 120 at 5 and 24 h storage surpassed the inhibitory effect of AA. At the said storage times, AA lost its inhibitory potential against pigment formation. This was due to oxidation of AA to form dehydroascorbic acid, which lacks inhibitory potential. This study proved that heating MO plant extracts increases their enzymatic browning inhibition potential, furthermore, the inhibitory capacity was heightened when reacted via the MR.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xianyuan Zeng ◽  
Liang Lyu ◽  
Dousha Zhao ◽  
Jinying Zhong ◽  
Yan Feng ◽  
...  

Lipids are the main energy source for embryonic development in oviparous animals. Prior to the utilization and catabolism, lipids are primarily transported from the yolk sac to embryonic tissues. In the present study, cDNA encoding a circulatory large lipid transfer protein (LLTP) superfamily member, the precursor of large discoidal lipoprotein (dLp) and high-density lipoprotein/β-1,3-glucan-binding protein (HDL-BGBP), named dLp/HDL-BGBP of 14,787 bp in length, was cloned from the mud crab Scylla paramamosain. dLp/HDL-BGBP was predicted to encode a 4,831 amino acids (aa) protein that was the precursor of dLp and HDL-BGBP, which were both detected in hemolymph by liquid chromatography–mass spectrometry (LC-MS/MS) analysis. For the intracellular LLTP, three microsomal triglyceride transfer protein (MTP) cDNAs of 2,905, 2,897, and 3,088 bp in length were cloned from the mud crab and were predicted to encode MTP-A of 881 aa, MTP-B of 889 aa, and MTP-C of 919 aa, respectively, which were different merely in the N-terminal region and shared an identical sequence of 866 aa. During embryonic development, the expression level of dLp/HDL-BGBP consecutively increased from the early appendage formation stage to the eye pigment-formation stage, which indicated that HDL-BGBP is probably the scaffolding protein for yolk lipid. For the MTP gene, MTP-C accounted for ~70% of MTP mRNA from the blastocyst stage to the nauplius stage, as well as the pre-hatching stage; MTP-C and MTP-A expression levels were comparable from the early appendage formation stage to the late eye pigment-formation stage; MTP-A was extremely low in blastocyst and gastrula stages; MTP-B was expressed at a relatively low-level throughout embryo development. The variations in the expression profiles among MTP transcripts suggested that MTP might play roles in the lipid droplet maturation and lipoprotein assembly during embryonic development.


2021 ◽  
Vol 15 (3) ◽  
pp. 1517-1526
Author(s):  
R. Kavitha ◽  
N. Damodharan

The current investigation was conducted to maximise the production of the natural anticancer drug from the microbe isolated from the marine soil sample of the Coromandel Coast of the Bay of Bengal region of India. Yellow to red colour pigmented microbes separated by crowd plate method. Bacteria are producing strong colour product subjected to future study. The isolated strains were detected based on biochemical, morphological, and genetic characteristics. Pigment formation was found to be influenced strongly by conditions of the environment. The water-insoluble pigment extracted by acidified methanol and showed maximum absorbance at 535nm. A statistical screening procedure was adopted to select the optimum condition to produce the pigment. The carbon, nitrogen, medium pH, growth condition temperature and revolution of agitation were screened using the response surface methodology statistical model. The near optimum conditions for the production medium were affected by the concentration of peanut, L-proline, percentage inoculum pH and incubation time. When these conditions were employed yield increased as two-fold as the concentration of prodigiosin 789 mg/l.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Qiqin Xue ◽  
Xiurong Zhang ◽  
Hui Yang ◽  
Huadong Li ◽  
Yuying Lv ◽  
...  

Peanut (Arachis hypogaea L.) is an important source of oil and food around the world, and the testa color affects its appearance and commercial value. However, few studies focused on the mechanism of pigment formation in peanut testa. In this study, cultivars Shanhua 15 with pink testa and Zhonghua 12 with red testa were used as materials to perform the combined analysis of transcriptome and metabolome. A total of 198 flavonoid metabolites were detected, among which petunidin 3-O-glucoside and cyanidin O-acetylhexoside in Zhonghua12 were 15.23 and 14.72 times higher than those of Shanhua 15 at the R7 stage, revealing the anthocyanins underlying the red testa. Transcriptome analysis showed that there were 6059 and 3153 differentially expressed genes between Shanhua 15 and Zhonghua 12 in different growth periods, respectively. These differentially expressed genes were significantly enriched in the flavonoid biosynthesis, biosynthesis of secondary metabolites, and metabolic pathways. Integrated analysis of transcriptome and metabolome indicated CHS gene (arahy.CM90T6), F3 ′ H genes (arahy. 8F7PE4 and arahy. K8H9R8), and DFR genes (arahy. LDV9QN and arahy. X8EVF3) may be the key functional genes controlling the formation of pink and red testa in peanut. Transcription factors MYB (arahy.A2IWKV, arahy.US2SKM, arahy.SJGE27, arahy.H8DJRL, and arahy.PR7AYB), bHLH (arahy.26781N, arahy.HM1IVV, and arahy.MP3D3D), and WD40 (arahy.L6JJW9) in the biosynthetic pathway of anthocyanin were significantly upregulated in Zhonghua 12 which may be the key regulatory genes in testa pigment formation. This is a comprehensive analysis on flavonoid metabolites and related genes expression in peanut testa, providing reference for revealing the regulatory mechanism of pigment accumulation in peanut testa.


2021 ◽  
Vol 7 (4) ◽  
pp. 289
Author(s):  
Jeong-Joo Oh ◽  
Young Jun Kim ◽  
Jee Young Kim ◽  
Sun Lul Kwon ◽  
Changsu Lee ◽  
...  

This study reports the draft genome of Amorphotheca resinae KUC30009, a fungal isolate with promising industrial-scale melanin production potential. The mechanisms for melanin or melanin-related pigment formation of this strain were examined through bioinformatic and biochemical strategies. The 30.11 Mb genome of A. resinae contains 9638 predicted genes. Genomic-based discovery analyses identified 14 biosynthetic gene clusters (BGCs) associated with secondary metabolite production. Moreover, genes encoding a specific type 1 polyketide synthase and 4-hydroxynaphthalene reductase were identified and predicted to produce intermediate metabolites of dihydroxy naphthalene (DHN)-melanin biosynthesis pathway, but not to DHN-melanin. These findings were further supported by the detection of increased flaviolin concentrations in mycelia and almost unchanged morphologies of the culture grown with tricyclazole. Apart from this, the formation of melanin in the culture filtrate appeared to depend on the laccase-like activity of multi-copper oxidases. Simultaneously, concentrations of nitrogen-containing sources decreased when the melanin formed in the media. Interestingly, melanin formation in the culture fluid was proportional to laccase-like activity. Based on these findings, we proposed novel strategies for the enhancement of melanin production in culture filtrates. Therefore, our study established a theoretical and methodological basis for synthesizing pigments from fungal isolates using genomic- and biochemical-based approaches.


2021 ◽  
Author(s):  
Andrew E Davis ◽  
Daniel Castranova ◽  
Brant M. Weinstein

The ability to carry out high-resolution, high-magnification optical imaging of living animals is one of the most attractive features of the zebrafish as a model organism. However, formation of obscuring pigmentation as development proceeds and difficulties in maintaining sustained immobilization of healthy, living animals remain challenges that limit the application of live imaging. Chemical treatments can be used to suppress pigment formation and movement, but these treatments can lead to developmental defects. Genetic mutants can also be used to eliminate pigment formation and immobilize animals but maintaining these mutants in lines carrying other combinations of transgenes and mutants is difficult and laborious. Here, we show that CRISPR duplex guide ribonucleoproteins (dgRNPs) targeting the slc45a2 (albino) and chrna1 (nic1) genes can be used to efficiently suppress pigment formation in and immobilize F0 injected animals. CRISPR dgRNPs can be used to generate pigment-free, immobile zebrafish embryos and larvae in any transgenic and/or mutant-carrying background, greatly facilitating high-resolution imaging and analysis of the many transgenic and mutant lines available in the zebrafish.


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