Effects of dietary supplementation with algal astaxanthin on growth,pigmentation,and antioxidant capacity of the blood parrot (Cichlasoma citrinellum × Cichlasoma synspilum )

An algal astaxanthin feeding trial was carried out to investigate the ef fects of natural astaxanthin from Haematococcus pluvialis as feed additives on growth, pigmenting efficacy and antioxidant capacity in blood parrot(C ichlasoma citrinellum × C ichlasoma. synspilum). Tissue total antioxidant capacity(TAC), superoxide dismutase(SOD), catalase(CAT) and maleic dialdehyde(MDA) were chosen as measures of its antioxidant capacity. All fish which received an astaxanthin(from micro-algal H. pluvialis) supplemented diet with 400 mg/kg of astaxanthin, after 50 days of feeding, the astaxanthin-fed fish displayed a pinkcolored skin and the control-fed fish displayed a grayish skin. For the growth, the weight gains of controlfed fish and astaxanthin-fed fish were 200% and 300%, respectively. Samples of skin and scales were used for analysis of total carotenoids and astaxanthin content, and fish feeding astaxanthin showed significantly( P <0.05) higher concentrations than the control group, indicating that the pigmentation of this fish had been significantly improved by dietary astaxanthin. Compared with the control fish, pigmented fish had lower SOD, CAT and MDA and higher TAC. It can be concluded that supplementation with dietary astaxanthin could eff ectively enhance growth, skin coloration and the antioxidant capacity of this fish. This study will provide a reference for application of natural astaxanthin from H. pluvialis as feed additives in blood parrot artificial breeding. Our data is also useful in ornamental fish farming, especially when the retentivity of astaxanthin in the skin and scales are involved. It is leading to the possibility of increasing the pigmentation of farmed-fish by adding the powdered form of H. pluvialis to the diet as an ef fective pigment.

Growth and pigmentation of halophilic archaea Haloarcula isolated from saltponds

Carotenoids accumulation in red halophilic archaea cells is considered apotential biotechnological product possessing a number of biological functions. Anarchaeal strain was isolated from brine water in a saltern crystallizer pond ofHanguSaltworks, China. 16S rRNA gene sequence analysis showed that it wasHaloarcula belonged to extremely halophilic archaea genus Halobacteriaceae. Todeterminethe effect of carbon source on the growth in Haloarcula cells, sucrose,lactose, glucose and soluble starch were supplemented into the culturemediumcontainingdissolved yeast extract and casein hydrolysate （10 g/L, 4：3 w/w） at alevel of 10 g/L, respectively, and sucrose was found to be a suitable one. To determinethe optimal supplementing levels of sucrose, three levels of sucrose （5, 10, 15 g/L）were added to the modified complete medium, and 10 g/L of sucrose supplementationwas optimal. The analysis of TLC and column gel chromatograph on pigment extractshowed five major pigments accumulated in Haloarcula cells, which werepreliminary detected as lycopene, bacterioruberin and its derivatives according to their absorptionpeak features.

The Effects of Trehalose on the Bioluminescence and Pigmentation of the Phase I Variant of Photorhabdus luminescens

Photorhabdus luminescens is a Gram-negative, bioluminescent, pigment producing enteric bacterium, which is pathogenic to insects and has the capability to undergo phase variation. The phase I variant of P. luminescens exists as a mutualistic symbiont where it plays a critical role in the life-cycle of the soil-dwelling nematode, Heterorhabditis bacteriophora. Both the bacterium and the nematode receive their nutritional requirements from the bioconversion of the insect host which is rich in many macromolecules such as the disaccharide, trehalose. Trehalose is a non-reducing disaccharide of glucose that is formed by an a-1,1-glycosidic bond and is associated with the physiology of many bacteria, insects and nematodes. Trehalose has been shown to be the most abundant storage sugar found within insect hemolymph （1%-2%）. The physicochemical properties of trehalose allow this carbohydrate to act as a stress protectant where it has been implicated with thermal stress, dehydration, and osmotic protection of many microorganisms. Due to these properties, trehalose may allow culture stability of the phase I variant in vitro and in vivo. Traits of the phase I variant that were studied in this work include bioluminescence and the production of the red anthroquinone-derived pigment. The carbohydrates that were utilized in this study were glucose and trehalose; where shake flask cultures of the phase I variant were cultured at room temperature for up to six days in carbohydrate supplemented basal media with increasing carbohydrate concentrations of 0. 1%, 0.5% and 1.0% （v/v）. Relative luminosity, pigmentation and pH were graphed as a function of time, carbohydrate used, and carbohydrate concentration. Data obtained from this study suggests that the supplementation of 1.0% trehalose, when culturing the phase I variant ofP. luminescens, can maintain bioluminosity and pigmentation over extended periods of time （five days） as compared to basal media and basal media supplemented with 1.0% glucose.

Turbot Scophthalmus maximus: stocking density on growth, pigmentation and feed conversion

Juvenile turbot （Scophthalmus maximus） the initial stock densities at 0.28, 0.87, 1.12, 1.16, 2.75 were reared in five different experiment groups in kg/m^2 respectively for the study of the density effect on growth, pigmentation and feed coefficient rate. The experiment lasted for 60 days with final stock densities at 1.91, 6.31, 8.86, 11.97, 17.67 kg/m^2 respectively. Result showed that, in the same experiment condition, the stocking density has a positive effect on growth in low density and negative in high density. The SGR （special growth rate） was 3.189, 3.304, 3.447, 3.341, and 3.087 respectively. The uniformity of weight distributing among experiment groups decreased with increasing density. The stocking density had positive effect on feed coefficient rate. Group 1 had the least feed coefficient rate 0.96, and highest at 1.25 in Group 5, the highest density group. High stocking density inhibited the growth and increased the feed coefficient rate. The stocking density had negative relationship to pigmentation improvement for whitened fish.

Evaluation of a resoruf in-based fluorescent probe for tyrosinase detection in skin pigmentation disorders

Purpose Skin pigmentation disorders,such as vitiligo and melasma,are difficult to diagnose in the early stages,but abnor-mal tyrosinase levels and tyrosinase activity are potential indicators.Some resorufin-based fluorescence probes(RBFPs)have been designed to detect tyrosinase in tumors,but they have not been used in skin pigmentation disorders.In this study,one of these RBFPs(synthesized by resorufin salt coupled with 3-(bromomethyl)phenol)was evaluated comprehensively.Methods The RBFP was tested in different kinds of mouse and human skin cells,as well as in in vivo models,including zebrafish,guinea pigs,and Sprague-Dawley rats.In addition,small interfering RNAs(siRNAs),kojic acid,and 1-phenyl-2-thiourea(PTU)were used to inhibit tyrosinase levels or tyrosinase activity.Results This probe successfully detected tyrosinase and emitted red fluorescence in melanoma cells and melanocytes.Fluorescence was also observable in zebrafish and on the skin of guinea pigs when using the RBFP.In mouse and human cells,the RBFP showed good selectivity to tyrosinase.Moreover,in the case of decreased tyrosinase levels or activity caused by siRNAs,kojic acid,or PTU,the probe was sensitive to these changes.Further,the RBFP showed no toxic effects at concentrations of<20μmol/L,both in vitro and in vivo.Conclusions Our findings indicate the value and limitations of the RBFP in tyrosinase detection,but suggest the need for further improvement of fluorescent probes in the diagnosis of skin pigmentation disorders.

Genetics and Characteristics of a Pigmentation Defective Laboratory Strain of the Lady Beetle, Coleomegilla maculata

Beetles in the family Coccinellidae, commonly known as ladybugs, lady beetles, or ladybirds, are easily identifiable and popular beneficial insects. Current research aims to support conservation efforts of beneficial insects in agroecosystems by exploring genetic processes related to nutrition. As a part of this research, colonies of Coleomegilla maculata have been maintained in culture and inbred over many generations since 2009. One result of this inbreeding has been the discovery of novel morphological phenotypes unique to laboratory strains or present in wild populations at such low levels that they have not yet been described. One such phenotype is described here. The strain described here, ye (yellow elytra and eyes) was characterized with classical Mendelian breeding and digital image analysis. This phenotype differs from wild populations by possessing yellow pigment in the elytra and pale grey to white eyes. In contrast, wild populations of C. maculata possess pink or red pigmented elytra with black spots, and black eyes. C. maculata is not known to exhibit polymorphism in the field. Inheritance is autosomal and recessive. This species was not previously known to exhibit the dramatic variation of color described here. The strain is stable in the homozygous recessive form, and retains laboratory rearing characteristics similar to the wild type laboratory strain.

Segmental Pigmentation Disorder with Congenital Heterochromia Iridis

We report the case of a 10-year-old girl with congenital complete heterochromia iridis and segmental pigmentation disorder in its hyperpigmented form. We have found no publication that mentions the combination of these 2 disorders.

Study on Development of Formulated Feed for Improving Growth and Pigmentation of Koi Carp （Cyprinus carpio L,, 1758） Juveniles

The aim of the present study was to develop a formulated feed for improving skin pigmentation and growth performance of koi carp juveniles. Two experiments were conducted for determination of an optimal dietary astaxanthin and FM （fish meal） ration for koi carp juveniles. In the first experiment, three isonitrogenous and isoenergetic dietary treatments were designed with three different levels of astaxanthin consisted of 60, 80 and 100 mg/kg and a commercial feed served as a control. For the second experiment, four isonitrogenous and isoenergetic dietary treatments were formulated with graded inclusions of dietary FM replaced from 0% to 60% at 20% increments by SM （soybean meal）, PBM （poultry by-product meal）, and a CD （control diet）. Obtained results demonstrated that skin pigmentation of koi carp juveniles fed the diet containing 80 mg/kg astaxanthin, 36.02% protein, 7.78% lipid, 4.20 Kcal/g GE （gross energy） were more better than those at the diet with lower estaxanthin content and commercial diet. Moreover, the highest growth and feed utilization of fish were observed at this diet with WG （weight gain）, SGR （specific growth rate） and FCR （feed conversion ratio） were 121.80%, 0.95 （%/day） and 1.6, respectively.

Electron Probe Microanalysis of Exogenous Pigmentation of Oral Mucosa Originating from Dental Alloy: Two Case Reports

Pigmentation of the oral mucosa is relatively common and has a wide variety of etiologies. Although most pigmented lesions of the oral mucosa are associated with deposition of melanin and accidental displacement of a dental alloy, accurate differential diagnosis of a pigmented lesion is important, especially in the case of malignant melanoma. We report two cases of oral mucosal pigmentation associated with accidental displacement of a dental alloy in which malignant melanoma was suspected. Excisional biopsy was carried out in these cases with the incision line set at approximately 5 mm from the lesions. Histopathologically, brownish foreign substances were observed in the lamina propria. Metal quantitative analyses of the extracted specimens were carried out by electron probe microanalysis (EPMA). The metal components and the mass concentration revealed that the metals were derived from a dental casting silver alloy in Case 1 and from a gold-silver palladium alloy in Case 2. Although exogenous pigmentation originating from a dental alloy is not rare, differential diagnosis of oral pigmented lesions is sometimes very difficult. In such cases, histopathological examination may be necessary for the diagnosis to exclude melanocytic lesions and EPMA may be effective to identify the causative dental alloy.

Periorbital Post-Inflammatory Hyperpigmentation after Fractionated CO₂Laser Resurfacing in Asians

Background: Most data on laser resurfacing have come from studies of people with Fitzpatrick skin types 1 - 3;however, the world’s population is comprised mostly of Fitzpatrick skin types 4 - 6, which are more susceptible to post-inflammatory hyperpigmentation (PIH). Objective: For the purpose of expanding the expertise of plastic surgeons treating patients with darker skin types, this study examined the incidence of PIH in Asians who underwent laser resurfacing, including a histologic arm on fractional ablative resurfacing. Methods & Materials: The clinical study included six subjects of Vietnamese origin who underwent single-depth fractionated CO2 laser resurfacing. The histologic study involved a seventh subject. The MiXto SX&reg;laser with a new scanning handpiece was used, along with magnifying loupes to assess ablative depth after each of three laser passes performed. Photographs were taken at various postoperative intervals. Results: All six clinical subjects showed cosmetic improvement in skin texture and tone with no post-inflammatory hyperpigmentation. In the histologic study, H&E stained sections revealed uniform diathermy. Conclusion: It is possible to significantly reduce PIH in darker skinned subjects through use of a new scanning handpiece and a technique using loupes to assess the depth of ablative resurfacing. The histologic study confirms these findings.

Combined effects of light intensity and NH_4^+-enrichment on growth, pigmentation, and photosynthetic performance of Ulva prolifera(Chlorophyta)

The aim of this study was to investigate the effects of light intensity and enhanced nitrogen supply on the growth and photosynthesis of the green-tide macroalga, Ulvaprolifera. Thalli of U. prolifera were grown in natural or NH^-enriched seawater under two different light intensities for 7 days, and then the growth rate, pigmentation, and photosynthetic performance of the thalli were evaluated. The results show that the relative growth rate （RGR） was markedly higher under the high light level than under the low light level. Enrichment with NH~ enhanced the RGR under high light intensity, but did not affect RGR under low light intensity. In low light conditions, NH;-enrichment resulted in a marked decrease in the maximal photosynthetic rate （Pro） and the maximum carbon fixation rate （Vmax）, but it did not affect the half saturation constant for carbon （K0.5） or the ratio of Vmax to K0.5, which reflects the carbon acquisition efficiency. In high light conditions, Pm, K05, and the dark respiration rate （Rd） increased under NHI enrichment, but Vmax and the Vmax/Ko5 ratio decreased. Regardless of the light intensity, NH^＋4-enrichment did not affect the apparent photosynthetic efficiency （a）, which reflects the ability of the alga to use light energy at low light levels. Under both low and high light intensities, the chlorophyll a （Chl a）, chlorophyll b （Chl b）, and carotenoids （Car） contents in thalli were higher in NH1-enriched than in natural seawater, except that there was a decrease in the Chl b content of thalli in NH1-enriched seawater under low light intensity. Therefore, NH^＋4 enrichment improved the growth and photosynthetic performance of U. prolifera under high light intensity, but not under low light intensity. We discuss the possible mechanisms underlying these physiological responses.

Pigmentation Restored in Mutant Laboratory Strain of the Lady Beetle Coleomegilla maculata through Dietary Supplementation

A laboratory colony of Coleomegilla maculata (DeGeer), ye, selected for a pigmentation deficiency, was restored to near wild type cuticle coloration by adding crushed heads and wings of the red colored parental strain to the diet. While the wings and other colored portions of the cuticle re-gained the red color, the eyes of the pigmentation deficient insects were not changed from the pale mutant form. Plant derived carotenes lycopene and beta-carotene did not restore the mutant beetles to a visibly distinguishable red color. An additional pigmentation deficient mutant strain, gold, partially recovered red cuticle color when provided with diet containing pigmented insect particles. This work represents the first rescue of a color phenotype in a lady beetle.

Histological Study of the Liver Pigmentation of Chinese Fire-bellied Newt (Cynops orientalis) During Activity and Hibernation Periods

The pigmentation in the liver of Chinese fire-bellied newt(Cynops orientalis) was described during two periods of the annual cycle(summer activity and winter hibernation). A large number of melanin granules were gathered into clusters and distributed unevenly inside the pigment cells. Liver pigmentation(melanin content) was found unstable,varying during the annual cycle. During the hibernation period,pigmentation accumulation was shown to increase in the liver of the Chinese fire-bellied newt. Hepatocytes during the active period are approximately 14.64% larger than those in the hibernation period,while the nucleus is approximately 7.43% bigger during the active period when compared with that during the hibernation period. These findings indicate that variation in pigment distribution and hepatocyte morphology in Chinese fire-bellied newt liver may be an ecologically adaptive strategy to the adverse physiological conditions during hibernation.

Pigmentation Restored in Mutant Laboratory Strain of the Lady Beetle <i>Coleomegilla maculata</i>through Dietary Supplementation

A laboratory colony of Coleomegilla maculata (DeGeer), ye, selected for a pigmentation deficiency, was restored to near wild type cuticle coloration by adding crushed heads and wings of the red colored parental strain to the diet. While the wings and other colored portions of the cuticle re-gained the red color, the eyes of the pigmentation deficient insects were not changed from the pale mutant form. Plant derived carotenes lycopene and beta-carotene did not restore the mutant beetles to a visibly distinguishable red color. An additional pigmentation deficient mutant strain, gold, partially recovered red cuticle color when provided with diet containing pigmented insect particles. This work represents the first rescue of a color phenotype in a lady beetle.

Effects of fish meal replacement with Chlorella meal on growth performance,pigmentation,and liver health of largemouth bass(Micropterus salmoides)

Chlorella meal is a potential protein source for aquafeeds.However,the physiological response of carnivorous fish fed Chlorella meal remains elusive.This study evaluated the effects of replacing dietary fish meal with Chlorella meal on growth performance,pigmentation,and liver health in largemouth bass.Five diets were formulated to replace dietary fish meal of 0%(C0,control),25%(C25),50%(C50),75%(C75),and 100%(C100)with Chlorella meal,respectively.Total 300 fish(17.6±0.03 g)were randomly assigned to 15 tanks(3 tanks/group).Fish were fed the experimental diet twice daily for 8 weeks.The increased dietary Chlorella meal quadratically influenced the final body weight(FBW),weight gain rate(WGR),specific growth rate(SGR),and feed intake(FI),which were significantly lower in the C100 group than in the other groups(P<0.05).The feed conversion ratio(FCR)increased linearly or quadratically with dietary Chlorella meal.Dietary Chlorella meal linearly or quadratically increased the lutein content of plasma,liver,and dorsal muscle of largemouth bass(P<0.05).Compared to the C0 group,all supplemented Chlorella meal groups significantly improved the yellowness(b*)of the dorsal body(1.5 to 2.0 fold),abdominal body(1.5 to 1.8 fold),and dorsal muscle(3.8 to 5.4 fold)of largemouth bass(P<0.05).In addition,compared to the C0 group,the liver vacuolation area of fish was significantly increased in the C75 and C100 groups(P<0.05).Transcriptional levels of apoptosis-related genes of b-cell lymphoma-2(bcl2),caspase-9-like(casp9),and caspase-3a(casp3)were markedly upregulated(0.9 to 1.6 fold)in the C100 group compared to the C0 group(P<0.05).Based on the quadratic regression analysis between FBW,WGR,or SGR and dietary Chlorella meal level,largemouth bass had the best growth when replacing 31.7%to 32.6%of fish meal with 15.03%to 15.43%dietary Chlorella meal.The present results indicated that dietary supplementation with Chlorella meal(11.85%to 47.45%)significantly enhanced the pigmentation;however,total replacement of fish meal(40%)with Chlorella meal(47.45%)caused growth retardation,apoptosis,and liver damage in largemouth bass.

The contribution of the melanin pathway to overall body pigmentation during ontogenesis of Periplaneta americana

The most prominent colors observed in insects are black or brown, whose production is attributed to the melanin pathway. At present, though, the contribution of this pathway to overall body pigmentation throughout ontogenesis is still lacking. To address this question we examined the roles of 2 key melanin genes （TH and DDC）, in embryonic and postembryonic development of the American cockroach, Periplaneta americana. Our results show that the melanin pathway does not contribute to the light brown coloration observed in the first nymphs. However, the dark brown coloration in mid nymphs and adults is produced solely from the melanin pathway. In addition, the DDC RNAi results reveal that it is dopamine melanin, not DOPA melanin, acts as the main contributor in this process. Overall, present study provides a new insight into insect pigmentation suggesting that genetic mechanisms of coloration can change during ontogenesis. Future studies of additional basal insect lineages will be required to assess in more details the generality of this phenomenon.

The domestication-associated L1 gene encodes a eucomic acid synthase pleiotropically modulating pod pigmentation and shattering in soybean

Pod coloration is a domestication-related trait in soybean,with modern cultivars typically displaying brown or tan pods,while their wild relative,Glycine soja,possesses black pods.However,the factors regulating this color variation remain unknown.In this study,we cloned and characterized L1,the classical locus responsible for black pods in soybean.By using map-based cloning and genetic analyses,we identified the causal gene of L1 and revealed that it encodes a hydroxymethylglutaryl-coenzyme A(CoA)lyase-like(HMGL-like)domain protein.Biochemical assays showed that L1 functions as a eucomic acid synthase and facilitates the synthesis of eucomic acid and piscidic acid,both of which contribute to coloration of pods and seed coats in soybean.Interestingly,we found that L1 plants are more prone to pod shattering under light exposure than l1 null mutants because dark pigmentation increases photothermal efficiency.Hence,pleiotropic effects of L1 on pod color and shattering,as well as seed pigmentation,likely contributed to the preference forl1 alleles during soybean domestication and improvement.Collectively,our study provides new insights into the mechanism of pod coloration and identifies a new target for future de novo domestication oflegume crops.

CRISPR/Cas9-based mutation reveals Argonaute 1 is essential for pigmentation in Ostrinia fumacalis

Ostrinia fumacalis (Lepidoptera: Pyralidae) is one of the most destructive agricultural pests in Asia. Traditional pest-management methods include sex pheromone capture, transgenic crops that produce Bacillus thuringiensis toxin, and pesticides. Although these strategies control pest populations effectively, they also cause negative side effects, including dramatically increased pesticide resistance, severe pollution, and hazards for human health. Recently developed genome editing tools provide new prospects for pest management and have been successfully used in several species. However, few examples have been reported in the agricultural pest O. fumacalis due to a lack in genomic information. In this report, we identified only one transcript of O. fumacalis Argonaute 1 (OfAgo 1) gene from the genome and cloned the open reading frame. OfAgol presented the maximum expression at the embryo stage or in the fat body during the larval stages. To understand its function, an OfAgol mutant was constructed using the Clustered Regularly Interspaced Short Palindromic Repeat/RNA-guided Cas9 nuclease (CRISPR/Cas9). Mutagenesis of OfAgol disrupted cuticle pigmentation by dowregulating micro RNAs and pigmentation-related genes. This is the first report for the cloning and functional analysis of OfAgol, revealing a role of OfAgol in cuticle pigmentation. The current report also established a CRISPR/Cas9 system in O. fumacalisy providing a new insight for pest management.

Genome scan of pigmentation traits in Friesian-Jersey crossbred cattle

Pigmentation traits expressed in animals are visual characteristics that allow us to distinguish between breeds and between strains within breed. The objective of this study was to map quantitative trait loci （QTLs） affecting the pigmentation traits in approximately 800 F2 grand daughter dairy cattle from a Holstein-Friesian and Jersey cross breed cattle. Traits analyzed included pigmentation phenotypes on the body, teat and hoop. The phenoypes were collected from digital photos or visual inspection of live animals. QTL mapping was implemented using half-sib and line-of-descent inheritance models. Our analysis initially detected a number of significant QTLs on chromosomes： 2, 6, 13, 15, 18 and 22. The significant QTLs were divided into two groups： one group influencing the pigmentation color and the other group affecting the absence or level of pigmentation. The most significant QTL peaks were observed on Bovine taurus autosome 18 （BTA18） close to melanocortin 1 receptor （MC1R） for the color traits, on BTA6 close to the receptor tyrosine kinase （K/T） and BTA22 close to microphthalmia-associated transcription factor （M/TF） gene for the spotting traits. Association studies were conducted for candidate regions or genes known to affect pigmentation in dairy cattle.

In Vivo Modeling of Zebrafish Zinc Finger,MIZ-Type Containing 1 Expression and Its Effect on Pigmentation

Objective:The zinc finger,MIZ-type containing 1(ZMIZ1)gene has been identified as a possible susceptibility gene associated with vitiligo,therefore we conducted this study to investigate the role ofZMIZ1 in pigmentation.Methods:We generate a zebrafish loss-of-function model using morpholino oligonucleotides(MOs),and two orthologs of humanZMIZ1 have been annotated(ZMIZ1a andZMIZ1b).The expression profiles of ZMIZ1a and ZMIZ1b and their effects on the pigmentation in zebrafish were evaluated by using whole-mount in situ hybridization and melanin quantification.Statistical analysis was performed using the unpaired Studentt-test or one-way analysis.Results:Investigation of the temporal and spatial expressions of these two transcripts suggested that the expressions ofZMIZ1a andZMIZ1b in the brain start to emerge in a ubiquitous fashion from 2 days post-fertilization onwards.After the successful design and validation of MOs,we observed thatZMIZ1a andZMIZ1b MOs caused embryonic developmental delays and malformations in zebrafish.Further analysis of the melanin content in the morphants revealed thatZMIZ1a significantly(49.1%for 0.667 mmol/L inZMIZI1a group,P=0.03)reduced the melanin content in a dose-dependent manner,but only the highest concentration of injectedZMIZ1b MOs significantly(50%for 0.667 mmol/L inZMIZ1b group,P=0.02)reduced the melanin content.A tyrosinase inhibition assay indicated no significant difference between the morphants and wild-type zebrafish.Conclusion:This study successfully modeled a susceptibility gene identified by genome-wide association studies in a zebrafish loss-of-function model and provides insights into the biological mechanism of pigmentation.