Color Genes Research Articles

Mutation of CsARC6 affects fruit color and increases fruit nutrition in cucumber.

A mutation of CsARC6 not only causes white fruit color in cucumber, but also affects plant growth and fruit quality. Fruit color of cucumber is a very important agronomic trait, but most of the genes affecting cucumber white fruit color are still unknow, and no further studies were reported on the effect of cucumber fruit quality caused by white fruit color genes. Here, we obtained a white fruit mutant em41 in cucumber by EMS mutagenesis. The mutant gene was mapped to a 548kb region of chromosome 2. Through mutation site analysis, it was found to be a null allele of CsARC6 (CsaV3_2G029290). The Csarc6 mutant has a typical phenotype of arc6 mutant that mesophyll cells contained only one or two giant chloroplasts. ARC6 protein was not detected in em41, and the level of FtsZ1 and FtsZ2 was also reduced. In addition, FtsZ2 could not form FtsZ ring-like structures in em41. Although these are typical arc6 mutant phenotypes, some special phenotypes occur in Csarc6 mutant, such as dwarfness with shortened internodes, enlarged fruit epidermal cells, decreased carotenoid contents, smaller fruits, and increased fruit nutrient contents. This study discovered a new gene, CsARC6, which not only controls the white fruit color, but also affects plant growth and fruit quality in cucumber.

Genetic variation within the coat color gene of Melanocortin 1 Receptor (MC1R) in Mong Cai pigs of Vietnam

Abstract. Thuy CTT, Ha CD, Long TD, Hai TV, Long ST, Chi TT, Quyen TTH, Yen VH, Khanh NTM, Trung NQ, Trung NT. 2023. Genetic variation within the coat color gene of Melanocortin 1Receptor (MC1R) in Mong Cai pigs of Vietnam. Biodiversitas 24: 1735-1741. Pig (Sus scrofa) is considered one of the major domesticated animals in Vietnam. Various indigenous pig varieties have been successfully developed as the Vietnamese's main daily meat source. However, little information has been reported about the conservation of these indigenous pig varieties. In this study,the Mong Cai, a prized domestic pig breed in Vietnam, is well-characterized by a black saddle on the hips extending to the lower abdomen. As a result of the introduction of exotic breeds and crossbreeding, Mong Cai pigs exhibited various phenotypic characteristics and coat colors. We constructed a database of Melanocortin 1Receptor(MC1R) coding sequences, including the MC1Rsequences of 26 Mong Cai and 20 other pig breeds from Europe and Asia. Subsequently, 12 haplotypes were determined using 18 mutations in 46 individuals. The phylogenetic tree result indicated that the Mong Cai population was distributed into two distinct haplotypes. Moreover, Mong Cai pigs could belong to the Asian clade; however, six Mong Cai individuals formed a distinct cluster. These six individuals carried the nt729G gene, which is prevalent in European pigs. In addition, our study could provide a solid foundation for further investigation of the evolution of indigenous pig varieties in Vietnam.

Genome-wide association study for the extractable phenolic profile and coat color of common bean seeds (Phaseolus vulgaris L.)

BackgroundA large variation in seed coat colors and seed phenolic metabolites is present in common bean (Phaseolus vulgaris L.). The study of the relationships between seed coat color phenotype and the phenolic profile is an important step in the elucidation of the gene network involved in the phenylpropanoid biosynthetic pathway. However, this relationship is still poorly understood in this species.ResultsA genome-wide association study (GWAS) was used to investigate the genomic regions associated with the synthesis of 10 flavonoids (5 anthocyanins and 5 flavonols) and with 10 seed coat color traits using a set of 308 common bean lines of the Spanish Diversity Panel (SDP) which have been genotyped with 11,763 SNP markers.. A total of 31 significant SNP-trait associations (QTNs) were identified, grouped in 20 chromosome regions: 6 for phenolic metabolites on chromosomes Pv01, Pv02, Pv04, Pv08, and Pv09, 13 for seed coat color on chromosomes Pv01, Pv02, Pv06, Pv07, and Pv10, and 1 including both types of traits located on chromosome Pv08. In all, 58 candidate genes underlying these regions have been proposed, 31 of them previously described in the phenylpropanoid pathway in common bean, and 27 of them newly proposed in this work based on the association study and their homology with Arabidopsis anthocyanin genes.ConclusionsChromosome Pv08 was identified as the main chromosome involved in the phenylpropanoid pathway and in consequence in the common bean seed pigmentation, with three independent chromosome regions identified, Phe/C_Pv08(2.7) (expanding from 2.71 to 4.04 Mbp), C_Pv08(5.8) (5.89–6.59 Mbp), and Phe_Pv08(62.5) (62.58 to 63.28 Mbp). Candidate genes previously proposed by other authors for the color genes V and P were validated in this GWAS. Candidate genes have been tentatively proposed from this study for color genes B and Rk on Pv02, Asp on Pv07, and complex C on Pv08. These results help to clarify the complex network of genes involved in the genetic control of phenolic compounds and seed color in common bean and provide the opportunity for future validation studies.

Transcriptomic-based analysis to identify candidate genes for blue color rose breeding.

Analysis of the flower color formation mechanism of 'Rhapsody in Blue' by BF and WF transcriptomes reveals that RhF3'H and RhGT74F2 play a key role in flower color formation. Rosa hybrida has colorful flowers and a high ornamental value. Although rose flowers have a wide range of colors, no blue roses exist in nature, and the reason for this is unclear. In this study, the blue-purple petals (BF) of the rose variety 'Rhapsody in Blue' and the white petals (WF) of its natural mutant were subjected to transcriptome analysis to find genes related to the formation of the blue-purple color. The results showed that the anthocyanin content was significantly higher in BF than in WF. A total of 1077 differentially expressed genes (DEGs) were detected by RNA-Seq analysis, of which 555 were up-regulated and 522 were down-regulated in the WF vs. BF petals. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses of the DEGs revealed that a single gene up-regulated in BF was related to multiple metabolic pathways including metabolic process, cellular process, protein-containing complex, etc.Additionally, the transcript levels of most of the structural genes related to anthocyanin synthesis were significantly higher in BF than in WF. Selected genes were analyzed by qRT-PCR and the results were highly consistent with the RNA-Seq results. The functions of RhF3'H and RhGT74F2 were verified by transient overexpression analyses, and the results confirmed that both affect the accumulation of anthocyanins in 'Rhapsody in Blue'. We have obtained comprehensive transcriptome data for the rose variety 'Rhapsody in Blue'. Our results provide new insights into the mechanisms underlying rose color formation and even blue rose formation.

First report on CRISPR/Cas9 mediated editing of the eye colour gene, Tryptophan 2, 3-dioxygenase in egg plant shoot and fruit borer Leucinodes orbonalis Guenée (Lepidoptera: Crambidae)

First report on CRISPR/Cas9 mediated editing of the eye colour gene, Tryptophan 2, 3-dioxygenase in egg plant shoot and fruit borer Leucinodes orbonalis Guenée (Lepidoptera: Crambidae)

Effect of Plumage Colour Genes on Body Measurements and Heat Tolerant Traits of Indigenous Chicken

This study was aimed to examine the effect of plumage colour genes on the body measurements and heat tolerant traits of indigenous chicken. A total of two hundred (200) adult chicken with different plumage colours comprising of black, white, red, brown and grey of both sexes reared by smallholder farmers with similar management system in Lafia, Nasarawa state, Nigeria were randomly sampled. Data were collected randomly at five (5) different locations in Lafia as thus: Kwandere, Shabu, Sabon Pegi, Tudun Gwandara and Tudun Amba respectively. Six body traits and four heat tolerant traits were measured on each bird: body length, breast circumference, thigh circumference, foot length, total leg length, wing length and Body temperature, Rectal temperature, pulse rate and respiratory rate. There was significant difference (P<0.05) for thigh circumference. The highest values for thigh circumference was observed for the white and grey plumage coloured chicken although not significantly different for those of brown plumage coloured. No significant differences were observed for the body length, breast circumference, wing length, foot length and total leg length for all the plumage coloured chicken. There was significant difference (P<0.05) for respiratory rate and heat stress index. The highest respiratory rate and heat stress index was observed for the white plumage coloured chicken. The white plumage coloured chicken were thermally stressed due to their inability to absorbed and withstand heat. No significant differences were observed for the remaining four plumage colours. Higher values of thigh circumference are the characteristics of meatiness in chicken. The coloured plumage chicken (Black, red, brown and grey) from this study possess the ability to better survive and adapt to heat stress due to their tendencies to absorbed heat compared to their white plumage coloured counterpart.

Genetic mapping of a single nuclear locus determines the white flesh color in watermelon (Citrullus lanatus L.).

Flesh color is an important trait in watermelon (Citrullus lanatus L.). Several flesh color genes have been identified in watermelon; however, the inheritance of and the molecular basis underlying the white flesh trait remain largely unknown. In this study, segregation populations were constructed by crossing the canary yellow flesh line HSH-F with the white flesh line Sanbai to fine-map the white flesh gene in watermelon. Genetic analysis indicated that the white flesh trait is controlled by a single recessive locus, termed Clwf2. Map-based cloning delimited the Clwf2 locus to a 132.3-kb region on chromosome 6. The candidate region contains 13 putative genes, and four of them-Cla97C06G121860, Cla97C06G121880, Cla97C06G121890, and Cla97C06G121900-were significantly downregulated in the white flesh compared to the canary yellow flesh watermelon fruits. The Cla97C06G121890 gene, which encodes a tetratricopeptide repeat protein, showed almost no expression in the white flesh fruit before maturity, whereas it had a very high expression in the canary yellow flesh fruit at 18 days after pollination. Transmission electron microscopy revealed rounded and regularly shaped chromoplasts in both the canary yellow and white flesh fruits. Further quantitative real-time PCR analysis showed that the expression levels of several key plastid division genes and almost the entire carotenoid biosynthesis pathway genes were downregulated in the white flesh compared to the canary yellow flesh fruits. This study suggests that the proliferation inhibition of chromoplasts and downregulation of the CBP genes block the accumulation of carotenoids in watermelon and lead to white flesh. These findings advance and extend the understanding of the molecular mechanisms underlying white flesh trait formation and carotenoid biosynthesis in watermelon.

A novel heterozygote allele in caprine melanocortin 1 receptor (MC1R) gene: an association with heat stress traits.

Climate change negatively influences the productive and reproductive abilities of goats. There is a need to understand the relationship between heat stress and genes that may aid in the development of climate-resilient goats. Melanism variation in goats plays a role in thermoregulation, in which the melanogenic genes have a pleiotropic effect on the regulation of physiological responses and behavior that are altered due to heat stress in the animals. Thus, the present study was conducted to establish a possible association between the coat color gene (MC1R) and heat stress characteristics. The physiological responses and cortisol levels were recorded in forty different coat-colored goats. The genotyping of the animals revealed four SNPs at the 183rd (C/T), 332nd (C/G), 748th (G/T), and 801st (C/G) positions, among which the black and brown goat populations had novel SNPs at the 332nd position. Eight haplotypes were constructed, and an association study revealed that haplotypes (CCGG, TCGG, and CCTC) that were linked to white animals had lower cortisol values, rectal temperature, skin temperature, and respiration rate. The multivariate and cluster analyses revealed that the white goats were distinct from the rest of the goats. In addition, the docking results revealed the residues that were forming the interaction complex, which could play a role in melanogenesis in the animals and, in turn, the heat stress ability of the goats. Altogether, the results of the present study could pave the way for more research into coat color genes and their relationship with heat stress traits.

Fine Mapping and Identification of SmAPRR2 Regulating Rind Color in Eggplant (Solanum melongena L.)

Rind color is an economically important agronomic trait in eggplant that impacts consumer preferences. In this study, bulked segregant analysis and competitive allele-specific PCR were employed to identify the candidate gene for eggplant rind color through constructing a 2794 F2 population generated from a cross between "BL01" (green pericarp) and "B1" (white pericarp). Genetic analysis of rind color revealed that a single dominant gene controls green color of eggplant peel. Pigment content measurement and cytological observations demonstrated that chlorophyll content and chloroplast number in BL01 were higher than in B1. A candidate gene (EGP19168.1) was fine-mapped to a 20.36 Kb interval on chromosome 8, which was predicted to encode the two-component response regulator-like protein Arabidopsis pseudo-response regulator2 (APRR2). Subsequently, allelic sequence analysis revealed that a SNP deletion (ACT→AT) in white-skinned eggplant led to a premature termination codon. Genotypic validation of 113 breeding lines using the Indel marker closely linked to SmAPRR2 could predict the skin color (green/white) trait with an accuracy of 92.9%. This study will be valuable for molecular marker-assisted selection in eggplant breeding and provides theoretical foundation for analyzing the formation mechanism of eggplant peel color.

Digest: Multiple selective pressures drive color diversity in moths.

How are color polymorphisms maintained within populations? De Pasqual et al. (2022) showed that female wood tiger moths (Arctia plantaginis) that were heterozygous for a wing color gene had higher fertility, hatching success, and offspring survival. These findings suggest that the complex interaction between heterozygote advantage and pleiotropic effects maintains color variability through a balance between multiple and competing selective pressures in wild populations.

Fine mapping and cloning of a novel BrSCC1 gene for seed coat color in Brassica rapa L.

A novel BrSCC1 gene for seed coat color was fine mapped within a 41.1-kb interval on chromosome A03 in Brassica rapa and functionally validated by ectopic expression analysis. Yellow seed is a valuable breeding trait that can be potentiality applied for improving seed quality and oil productivity in oilseed Brassica crops. However, only few genes for yellow seed have been identified in B. rapa. We previously identified a minor quantitative trait locus (QTL), qSC3.1, for seed coat color on chromosome A03 in B. rapa. In order to isolate the seed coat color gene, a brown-seeded chromosome segment substitution line, CSSL-38, harboring the qSC3.1, was selected and crossed with the yellow-seeded recurrent parent, a rapid cycling inbred line of B. rapa (RcBr), to construct the secondary F2 population. Metabolite identification suggested that seed coat coloration in CSSL-38 was independent of proanthocyanidins (PAs) accumulation. Genetic analysis revealed that yellow seed was controlled by a single recessive gene, Seed Coat Color 1 (BrSCC1). Utilizing bulked segregant analysis (BSA)-seq and secondary F2 and F2:3 recombinants analysis, BrSCC1 was fine mapped within a 41.1-kb interval. By integrating gene expression profiling, genome sequence comparison, metabolite analysis, and functional validation through ectopic expression in Arabidopsis, the BraA03g040800.3C gene was confirmed to be BrSCC1, which positively correlated with the seed coat coloration. Our study provides a novel gene resource for the genetic improvement of yellow seeds in oilseed B. rapa.

The rat Downunder (Du) coat color mutation is associated with eye anomalies and embryonic lethality and maps to a 3.9-Mb region on chromosome 3.

Rodent coat color genes have been studied as a bioresource to understand developmental and cellular processes. The Downunder rat is a fancy variety with a marking on its belly that runs from the neck to the breech and appears to mirror the dorsal hooded marking. Here, we established a congenic strain carrying the Downunder (Du) gene in an F344 genetic background. In addition to the ventral marking, Du/+ rats exhibit anophthalmia or microphthalmia with incomplete penetrance. Du/Du embryos die in the early stages of organogenesis. Genetic linkage analysis mapped the Du gene to rat chromosome 3 and haplotype mapping with congenic rats localized the Du locus to a 3.9-Mb region. The Du locus includes two functional genes, glycosyltransferase-like domain-containing 1 (Gtdc1) and zinc finger E-box binding homeobox 2 (Zeb2). Although we found no functional variation within any of Zeb2's exons or intron-exon boundaries, Zeb2 mRNA levels were significantly lower in Du/+ rats compared with wild-type rats. It is known that melanocyte-specific Zeb2 deletion results in the congenital loss of hair pigmentation in mice. Taken together, our results indicate that the Du mutation exerts pleiotropic effects on hair pigmentation, eye morphology, and development. Moreover, the Zeb2 gene is a strong candidate for the Du mutation.

Fine mapping and identification of candidate genes for fruit color in pepper (Capsicum chinense)

The quality of pepper fruits is determined by numerous characteristics such as, flavor, color, and nutritional value. Through little is known about it, fruit color impacts breeding preferences in Capsicum chinense in a substantial way. In the present study, two C. chinense germplasms, HNUCC16 (dark green immature and yellow ripe fruit) and HNUCC22 (light green immature and red ripe fruit) were used to produce an F2 population. Based on genotyping-by-sequencing, we constructed a high-density genetic map of the F2 population with 1,347 bin markers and covered 1,206.37 cM in twelve pepper linkage groups. The trait segregation analysis of the F2 population show that the color of immature and mature fruits is controlled by a single locu . Bin markers 19 (chromosome 1) and 849 (Chromosome 6) were closely associated with the locus that regulates the color of immature and ripe fruits, respectively. The transformation of the two bin markers into dCAPS markers indicate that inactive shikimate kinase-like 2 (BC332_00870) may be a strong candidate gene for regulating immature fruit color, and the premature termination mutation of capsanthin–capsorubin synthase (BC332_17237) gene may possibly cause the yellow color in HNUCC16 pepper fruits. Overall, the findings of this study offer fundamental knowledge concerning the development of color and offer a new resource for pepper fruit color genetic improvement and molecular breeding.

Gene Expression in the Developing Seed of Wild and Domesticated Rice.

The composition and nutritional properties of rice are the product of the expression of genes in the developing seed. RNA-Seq was used to investigate the level of gene expression at different stages of seed development in domesticated rice (Oryza sativa ssp. japonica var. Nipponbare) and two Australian wild taxa from the primary gene pool of rice (Oryza meridionalis and Oryza rufipogon type taxa). Transcriptome profiling of all coding sequences in the genome revealed that genes were significantly differentially expressed at different stages of seed development in both wild and domesticated rice. Differentially expressed genes were associated with metabolism, transcriptional regulation, nucleic acid processing, and signal transduction with the highest number of being linked to protein synthesis and starch/sucrose metabolism. The level of gene expression associated with domestication traits, starch and sucrose metabolism, and seed storage proteins were highest at the early stage (5 days post anthesis (DPA)) to the middle stage (15 DPA) and declined late in seed development in both wild and domesticated rice. However, in contrast, black hull colour (Bh4) gene was significantly expressed throughout seed development. A substantial number of novel transcripts (38) corresponding to domestication genes, starch and sucrose metabolism, and seed storage proteins were identified. The patterns of gene expression revealed in this study define the timing of metabolic processes associated with seed development and may be used to explain differences in rice grain quality and nutritional value.

RNAi-Mediated Manipulation of Cuticle Coloration Genes in Lygus hesperus Knight (Hemiptera: Miridae).

Cuticle coloration in insects is a consequence of the accumulation of pigments in a species-specific pattern. Numerous genes are involved in regulating the underlying processes of melanization and sclerotization, and their manipulation can be used to create externally visible markers of successful gene editing. To clarify the roles for many of these genes and examine their suitability as phenotypic markers in Lygus hesperus Knight (western tarnished plant bug), transcriptomic data were screened for sequences exhibiting homology with the Drosophila melanogaster proteins. Complete open reading frames encoding putative homologs for six genes (aaNAT, black, ebony, pale, tan, and yellow) were identified, with two variants for black. Sequence and phylogenetic analyses supported preliminary annotations as cuticle pigmentation genes. In accord with observable difference in color patterning, expression varied for each gene by developmental stage, adult age, body part, and sex. Knockdown by injection of dsRNA for each gene produced varied effects in adults, ranging from the non-detectable (black 1, yellow), to moderate decreases (pale, tan) and increases (black 2, ebony) in darkness, to extreme melanization (aaNAT). Based solely on its expression profile and highly visible phenotype, aaNAT appears to be the best marker for tracking transgenic L. hesperus.

Genome-Wide Detection of Selection Signatures for Pelt Quality Traits and Coat Color Using Whole-Genome Sequencing Data in American Mink.

Domestication and selection are the major driving forces responsible for creating genetic variability in farmed species. American mink has been under selection for more than 100 years for improved body size and pelt quality. This study aimed to identify the genomic regions subjected to selection for pelt quality traits, and coat color using the whole genome sequences of 100 mink raised in the Canadian Centre for Fur Animal Research (CCFAR) at Dalhousie Agriculture Campus (Truro, NS, Canada), and Millbank fur farm (Rockwood, ON, Canada). Measurements of three dried pelt characteristics (including pelt size (n = 35), overall quality of fur (n = 27), and nap size (n = 29)), and three coat color of Black, Stardust, and Pastel (Stardust_ Black (n = 38), and Pastel_Black (n = 41)) were used to assign animals to pairwise groups. Signatures of selection were detected using integrated measurement of fixation index (Fst), extended haplotype homozygosity (XP-EHH), and nucleotide diversity (θπ) tests. In total, overlapping top 1% of Fst and XP-EHH harbored 376 genes for pelt quality traits (110 for nap size, 163 for overall quality of fur, and 98 pelt size), and 194 genes for coat color (123 for Pastel_Black and 71 for Stardust_Black) were detected in different groups. Integrating results of Fst, and XP-EHH with the θπ test supported 19 strongly selected regions on chromosomes 3, 4, 5, 6, 7, 8, 9, and 10 that contained 33 candidate genes related to fur quality, hair follicle function, and pelt size traits. Gene ontology revealed numerous genes related to the hair cycle process and molting cycle process, epidermis development, Wnt signaling pathway and muscle development. This study provided the first map of putative selection signals related to pelt quality and coat color in American mink, which could be used as a reference for future studies attempting to identify genes associated with economically important traits in mink.

Identification of Candidate Genes for Rind Color and Bloom Formation in Watermelon Fruits Based on a Quantitative Trait Locus-Seq.

Watermelon fruit rind color (RC) and bloom formation (BF) affect product value and consumer preference. However, information on the candidate gene(s) for additional loci involved in dark green (DG) RC and the genetic control of BF and its major chemical components is lacking. Therefore, this study aimed to identify loci controlling RC and BF using QTL-seq of the F2 population derived by crossing ‘FD061129’ with light-green rind and bloom and ‘SIT55616RN’ with DG rind and bloomless. Phenotypic evaluation of the F1 and 219 F2 plants indicated the genetic control of two complementary dominant loci, G1 and G2, for DG and a dominant locus, Bf, for BF. QTL-seq identified a genomic region on Chr.6 for G1, Chr.8 for G2, and Chr.1 for Bf. G1 and G2 helped determine RC with possible environmental effects. Chlorophyll a-b binding protein gene-based CAPS (RC-m5) at G1 matched the highest with the RC phenotype. In the 1.4 cM Bf map interval, two additional gene-based CAPS markers were designed, and the CAPS for a nonsynonymous SNP in Cla97C01G020050, encoding a CSC1-like protein, cosegregated with the BF trait in 219 F2 plants. Bloom powder showed a high Ca2+ concentration (16,358 mg·kg−1), indicating that the CSC1-like protein gene is possibly responsible for BF. Our findings provide valuable information for marker-assisted selection for RC and BF and insights into the functional characterization of genes governing these watermelon-fruit-related traits.

Seed coat colour of Indian mustard [Brassica juncea (L.) Czern. and Coss.] is associated with Bju.TT8 homologs identifiable by targeted functional markers.

Seed coat colour is an important trait in Indian mustard. Breeding for seed coat colour needs precise knowledge of mode of inheritance and markers linked to it. The present study was focussed on genetics and development of functional markers for seed coat colour. F1s (direct and reciprocal) and F2 populations were developed by crossing two contrasting parents for seed coat colour (DRMRIJ-31, brown seeded and RLC-3, yellow seeded). Phenotypic results have shown that the seed coat colour trait was under the influence of maternal effect and controlled by digenic-duplicate gene action. Further, Bju.TT8 homologs of both parents (DRMRIJ-31 and RLC-3) were cloned and sequenced. Sequencing results of Bju.TT8 homologs revealed that in RLC-3, gene Bju.ATT8 had an insertion of 1279bp in the 7th exon; whereas, gene Bju.BTT8 had an SNP (C→T) in the 7th exon. These two mutations were found to be associated with yellow seed coat colour. Using sequence information, functional markers were developed for both Bju.TT8 homologs, validated on F2 population and were found highly reliable with no recombination between the markers and the phenotype. Further, these markers were subjected to a germplasm assembly of Indian mustard, and their allelic combination for the seed coat colour genes has been elucidated. The comparative genomics of TT8 genes revealed high degree of similarity between and across the Brassica species, and the respective diploid progenitors in tetraploid Brassica species are the possible donors of TT8 homologs. This study will help in the marker-assisted breeding for seed coat colour, and aid in understanding seed coat colour genetics more precisely.

Basal Reactivity Evaluated by Infrared Thermography in the "Caballo de Deporte Español" Horse Breed According to Its Coat Color.

Simple SummaryThe importance of the coat color in horses has been present since their domestication. The interactive effect of coat color-determinant genes on other traits, such as behavior, makes it a factor of importance in horse selection, as it determines the way the horse perceives and reacts to its environment. Eye temperature at rest (ETR) assessed with infrared thermography was used as a suitable non-invasive tool to assess basal reactivity. The aim of this study was to evaluate the influence of coat color on basal reactivity assessed with infrared thermography, determine their relationship with the results obtained in show jumping competitions, and to estimate the genetic parameters for ETR to test its suitability for genetic selection. Our results indicated differences in ETR due to six different factors. We also discovered a positive correlation with ranking in show jumping, indicating that less reactive horses were more likely to achieve better rankings. The genetic results indicated that part of the variability present in the basal reactivity due to coat color has an environmental origin. The heritability values indicate that ETR has a suitable genetic basis to be used in the breeding program to select for basal reactivity due to coat color.Horses have been valued for their diversity of coat color since prehistoric times. In particular, the pleiotropic effect that coat color genes have on behavior determines the way the horse perceives and reacts to its environment. The primary aim of this study was to evaluate the influence of coat color on basal reactivity assessed with infrared thermography as eye temperature at rest (ETR), determine their relation with the results obtained by these horses in Show Jumping competitions and to estimate the genetic parameters for this variable to test its suitability for genetic selection. A General Linear Model (GLM) and Duncan post-hoc analysis indicated differences in ETR due to coat color, sex, age, location, and breed-group factors. A Spearman’s rank correlation of 0.11 (p < 0.05) was found with ranking, indicating that less reactive horses were more likely to achieve better rankings. Heritability values ranged from 0.17 to 0.22 and were computed with a model with genetic groups and a model with residual variance heterogeneity. Breeding values were higher with the last genetic model, thus demonstrating the pleiotropic effect of coat color. These results indicate that ETR has a suitable genetic basis to be used in the breeding program to select for basal reactivity due to coat color.

Effects of light color, photoperiod, and growth-related gene interference or overexpression on the survival, growth, or physiological and biochemical indices of red claw crayfish juveniles

To determine the optimal light color and photoperiod conditions for red claw crayfish juveniles, we studied the effects of these factors on their survival, growth, monoamine content, antioxidant capacity, nonspecific immune index, and the expression of EcR and α-AMY genes. Experiments involving five light color groups (red, green, blue, yellow, and white light), five photoperiod groups (0 L:24D, 6 L:18D, 12 L:12D, 18 L:6D, and 24 L:0D), besides, we also studied the effects of interference and overexpression of these genes on growth, survival, and their expression. (1) The red light group showed the highest survival rate, while the blue light group showed the fastest growth rate. Further, the red light group showed significantly higher superoxide dismutase [SOD], acid phosphatase [ACP], and alkaline phosphatase [AKP] activities, but significantly lower malondialdehyde [MDA], serotonin [5-HT], noradrenaline [NE], and dopamine [DA] concentrations. The yellow light group presented significantly higher SOD activity, and lower DA concentration. The blue light group showed the highest α-AMY expression level, while the EcR expression levels corresponding to the yellow and red light groups were significantly higher. (2) The 0 L:24D and 6 L:18D photoperiod groups showed significantly higher survival rates than the 24 L:0D group. Additionally, the SOD and ACP activities corresponding to the 6 L:18D and 0 L:24D group were significantly higher, while its MDA and DA concentrations were significantly lower. (3) The 6 L:18D, 12 L:12D, and 0 L:24D groups showed significantly higher α-AMY expression levels, while EcR expression was significantly higher in the 6 L:18D and 0 L:24D groups. (4) EcR or α-AMY gene interference or overexpression had no significant effect on juvenile crayfish survival. However, interfering with ECR expression reduced juvenile growth rate, while ECR or α-AMY gene overexpression enhanced their growth rate. Overall, red claw crayfish juveniles showed higher survival rates, greater antioxidant and immune activities, and lower monoamine contents under red light, 6 L:18D or 0 L:24D conditions. Thus, these conditions possibly improved digestion and absorption and also promoted molting in the juveniles. Additionally, ECR and α-AMY expression could reflect the growth rate of the juveniles, but not their survival.