Search Results (33)

Background: Polymorphisms in the FADS1 and FADS2 genes influence fatty acid metabolism. However, evidence of gene–diet interactions in population-based studies from Brazil remains limited. The objective of this study was to examine associations between FADS1–FADS2 single-nucleotide polymorphisms (SNPs) and erythrocyte fatty acid composition and serum lipid concentrations, as well as to explore potential gene–diet interactions. Methods: Data were analyzed from 294 adults (20–93 years) enrolled in the 2015 ISA-Nutrition study. Erythrocyte fatty acid composition and serum lipids were measured using standard enzymatic methods. Dietary intake was assessed by 24 h recalls, and participants were classified into tertiles according to fatty acid intake. Five SNPs were genotyped; FADS1 rs174546 and FADS2 rs174570 were prioritized based on linkage disequilibrium. Associations and interactions were assessed using generalized linear models, adjusting for confounders. Results: Carriers of the minor alleles for rs174546 and rs174570 had significantly lower erythrocyte levels of long-chain polyunsaturated fatty acids, particularly along the ω-6 pathway, suggesting reduced desaturase activity. The rs174546 TT genotype was associated with higher total, very-low-density lipoprotein cholesterol (VLDL), and non–high-density lipoprotein (non-HDL) cholesterolconcentrations. Higher dietary intakes of docosahexaenoic acid (DHA) or a higher linoleic acid to alpha-linolenic acid ratio(LA/ALA ratio) among these carriers were linked to lower serum lipid levels, indicating gene–diet interactions that attenuate adverse genotype effects. In addition, rs174570 TT carriers showed elevated VLDL concentrations, with a significant dietary interaction observed with the LA/ALA ratio. Conclusions: FADS1 and FADS2 polymorphisms influence fatty acid metabolism and interact with diet to shape lipid profiles. These findings highlight the importance of considering gene-diet interactions in cardiometabolic risk. Full article

Flax (Linum usitatissimum L.) is a globally important oilseed crop, valued for its edible and industrial uses. Flax seeds are rich in unsaturated fatty acids. In this study, ethyl methyl sulfone was employed to construct a mutant library from the flax cultivar Longya 10 (WT). Screening efforts identified M45, a stable mutant with an oleic acid content of 43.22% at 40 days after flowering, representing a 21.23% increase over the wild-type. RNA-Seq analysis revealed the presence of two homologs of the SAD (stearoyl-ACP desaturase) family and two homologs of the FAD2 (fatty acid desaturase 2) family, which showed differential expression in a trend consistent with the phenotype of M45. A BSA-Seq analysis was conducted to identify genes with SNPs (single nucleotide polymorphisms) and Indel (insertions/deletions) variant loci that were associated with increased oleic acid. The combination of BSA-Seq, RNA-Seq, and metabolomic analyses identified L.us.o.g.scaffold122.86, a gene that may be co-expressed with L.us.o.g.scaffold7.26 to affect oleic acid accumulation via FAD2. Full article

Epidemiological studies report inconsistent findings regarding the association between dietary polyunsaturated fatty acid (PUFA) intake and cancer risk. Genetic variations—particularly single-nucleotide polymorphisms (SNPs) in the FADS1 and FADS2 genes—affect PUFA metabolism, linking circulating PUFA levels to the risk of several cancers, including breast, colorectal, prostate, and pancreatic cancers. This review aimed to investigate the relationship between FADS1 and FADS2 gene variants and dietary intake, supplementation, or intervention with omega-3 fatty acids, gamma-linolenic acid (GLA), or their combination in cancer patients. A secondary objective was to examine genetically determined fatty acid profiles—shaped by FADS1 and FADS2 polymorphisms—in cancer patients without intervention and their potential association with PUFA-related cancer risk. A systematic search of the Scopus, PubMed, and Web of Science databases (up to 2024) identified 11 eligible studies out of 298 initial records. Analysis of the available literature suggests that specific FADS genotypes influence long-chain PUFA (LC-PUFA) concentrations in blood and tissues and that altered LC-PUFA levels may contribute to cancer development. The most consistent association identified is between the rs174537 variant and altered PUFA metabolism in prostate and breast cancer. However, conclusive evidence is lacking on the impact of dietary patterns on FADS desaturase activity or expression. Only one study has examined omega-3 supplementation in relation to FADS gene variants in prostate cancer patients, while the effects of GLA supplementation remain unexplored. Given the relative novelty of this research area and the limited number of studies, future investigations should integrate dietary PUFA intake, genetic variation in PUFA-metabolizing enzymes, and potential gene–nutrient interactions involving FADS gene polymorphisms and PUFAs to clarify their role in cancer risk. Full article

The rapid identification of allele variants in target genes is crucial for accelerating marker-assisted selection (MAS) in plant breeding. Although current high-throughput genotyping methods are efficient in detecting known polymorphisms, they are limited when multiple variant sites are scattered along the gene. This study presents a target amplicon sequencing approach using Oxford Nanopore Technologies (ONT-TAS) to rapidly sequence full-length genes and identify allele variants in sunflower and wheat collections. This procedure combines multiplex PCR and a rapid sequencing kit, significantly reducing the time and cost compared to previous methods. The efficiency of the approach was demonstrated by sequencing four genes (Ahasl1, Ahasl2, Ahasl3, and FAD2) in 40 sunflower genotypes and three genes (Ppo, Wx, and Lox) in 30 wheat genotypes. The ONT-TAS revealed a complete picture of SNPs and InDels distributed over the individual alleles, enabling rapid (4.5 h for PCR and sequencing) characterization of the genetic diversity of the target genes in the germplasm collections. The results showed a significant diversity of the Ahasl1/Ahasl3 and Wx-A/Lox-B genes in the sunflower and wheat collections, respectively. This method offers a high-throughput, cost-effective (USD 3.4 per gene) solution for genotyping and identifying novel allele variants in plant breeding programs. Full article

Long-chain polyunsaturated fatty acids (LC-PUFAs) are crucial for human health and cannot be produced internally. Bivalves, such as oysters, serve as valuable sources of high-quality PUFAs. The enzyme fatty acid desaturase (FADS) plays a key role in the metabolism of LC-PUFAs. In this study, we conducted a thorough genome-wide analysis of the genes belong to the FADS family in Crassostrea gigas and Crassostrea angulata, with the objective of elucidating the function of the FADS2 and investigating the genetic variations that affect PUFA biosynthesis. We identified six FADS genes distributed across four chromosomes, categorized into three subfamilies. The coding region of FADS2 revealed five non-synonymous mutations that were shown to influence protein structure and stability through molecular dynamics simulations. The promoter region of FADS2 contains ten SNPs and three indels significantly correlated with PUFA content. These genetic variations may explain the differences in PUFA levels observed between the two oyster species and could have potential applications in enhancing PUFA content. This study improves the molecular understanding of PUFA metabolism in oysters and presents a potential strategy for selecting oysters with high PUFA levels. Full article

The SCD is a rate-limiting enzyme that catalyzes the synthesis of monounsaturated fatty acids (MUFAs) in dairy cows; however, its role in the mammary gland of buffalo is not well understood. In this study, we isolated and characterized the complete coding sequence (CDS) of the buffalo SCD gene from mammary gland tissue and investigated its effects on milk fat synthesis using bioinformatics analyses, tissue differential expression detection, and cellular functional experiments. The cloned SCD gene has a CDS length of 1080 bp, encoding a protein of 359 amino acids. This protein is hydrophilic, lacks a signal peptide, and contains four transmembrane domains, including 10 conserved motifs and a Delta9-FADS domain, characteristic of the fatty acid desaturase family involved in unsaturated fatty acid biosynthesis within the endoplasmic reticulum. Molecular characterization revealed that the physicochemical properties, conserved domains, structures, and functions of buffalo SCD are highly similar to those in other Bovidae species. Among the tissues analyzed, SCD expression was highest in the mammary gland during lactation and in the cerebellum during dry-off period. Notably, SCD expression in the mammary gland was significantly higher during lactation compared to the dry-off period. Subcellular localization experiments confirmed that SCD functions in the endoplasmic reticulum of buffalo mammary epithelial cells (BuMECs). Functional overexpression and interference experiments in BuMECs demonstrated that SCD promotes milk fat synthesis by affecting the expression of lipid synthesis-related genes such as ACACA, FASN, and DGAT1, as well as milk fat regulatory genes like SREBFs and PPARG, thereby influencing intracellular triglyceride (TAG) content. Additionally, 18 single-nucleotide polymorphisms (SNPs) were identified in the buffalo SCD gene, with a specific SNP at c.-605, showing potential as molecular markers for improving milk production traits. These findings highlight that the SCD gene is a key gene in buffalo milk fat synthesis, involved in the de novo synthesis of milk fatty acids. Full article

Temperament can be defined as the emotional variability among animals of the same species in response to the same stimulus, grouping animals by their reactivity as nervous, intermediate, or calm. Our goal was to identify genomic regions with the temperament phenotype measured by the Isolation Box Test (IBT) by single-step genome-wide association studies (ssGWAS). The database consisted of 4317 animals with temperament records, and 1697 genotyped animals with 38,268 effective Single Nucleotide Polymorphism (SNP) after quality control. We identified three genomic regions that explained the greatest percentage of the genetic variance, resulting in 25 SNP associated with candidate genes on chromosomes 6, 10, and 21. A total of nine candidate genes are reported for the temperament trait, which is: PYGM, SYVN1, CAPN1, FADS1, SYT7, GRID2, GPRIN3, EEF1A1 and FRY, linked to the energetic activity of the organism, synaptic transmission, meat tenderness, and calcium associated activities. This is the first study to identify these genetic variants associated with temperament in sheep, which could be used as molecular markers in future behavioral research. Full article

The cultivated peanut (Arachis hypogaea L.) is an important oilseed crop worldwide, and fatty acid composition is a major determinant of peanut oil quality. In the present study, we conducted a genome-wide association study (GWAS) for nine fatty acid traits using the whole genome sequences of 160 representative Chinese peanut landraces and identified 6-1195 significant SNPs for different fatty acid contents. Particularly for oleic acid and linoleic acid, two peak SNP clusters on Arahy.09 and Arahy.19 were found to contain the majority of the significant SNPs associated with these two fatty acids. Additionally, a significant proportion of the candidate genes identified on Arahy.09 overlap with those identified in early studies, among which three candidate genes are of special interest. One possesses a significant missense SNP and encodes a known candidate gene FAD2A. The second gene is the gene closest to the most significant SNP for linoleic acid. It codes for an MYB protein that has been demonstrated to impact fatty acid biosynthesis in Arabidopsis. The third gene harbors a missense SNP and encodes a JmjC domain-containing protein. The significant phenotypic difference in the oleic acid/linoleic acid between the genotypes at the first and third candidate genes was further confirmed with PARMS analysis. In addition, we have also identified different candidate genes (i.e., Arahy.ZV39IJ, Arahy.F9E3EA, Arahy.X9ZZC1, and Arahy.Z0ELT9) for the remaining fatty acids. Our findings can help us gain a better understanding of the genetic foundation of peanut fatty acid contents and may hold great potential for enhancing peanut quality in the future. Full article

Twenty-seven genotypes of varieties and advanced breeding lines were grown in two locations in three years with three replications to estimate the effects of the genotype-by-environment interaction (G × E) on the oil and oleic fatty acid contents of cultivated peanuts. Oil and oleic fatty acid contents were quantified using NMR and GC, respectively. The tested lines were genotyped with functional SNP markers from the FAD2A and FAD2B genes using real-time PCR and classified into four genotypes. The results indicated that Alabama was the environment that better discriminated the test genotypes during the year 2012. Eight promising selected genotypes #12, #15, ARSOKR, Brantley, GaHO, M04-149, M04-48, and SunO97R showed wide adaptation and high-oleic acids of 83.02%, 81.32%, 82.03%, 81.15%, 79.21%, 80.94%, 82.46%, and 82.18%, respectively. The Additive Main Effects and Multiplicative Interaction (AMMI) model that combines the conventional analyses of variance for additive main effects with the principal component analysis (PCA) for the non-additive residuals was applied to estimate the additive effects from FAD2A and FAD2B genes and the G × E interaction. The results indicated significant G × E interactions for oleic fatty acid contents. No correlation between oil content and FAD2A and FAD2B genes was found. The FAD2B gene had a larger additive effect than the FAD2A gene. The results from this study may be useful not only for peanut breeders, but also for food processors and product consumers to select suitable cultivars. Full article

The Chinese indigenous Shiqi (SQ) pigeon and the imported White King (WK) pigeon are two meat-type pigeon breeds of economical and nutritional importance in China. They displayed significant differences in such meat quality traits as intramuscular fat (IMF) content and fatty acid (FA) compositions in the breast muscles. In this study, we aimed to screen candidate genes that could affect fat-related meat quality traits in meat-type pigeons. We investigated the polymorphic variations at the genomic level using double-digest restriction-associated DNA (ddRAD) sequencing in 12 squabs of SQ and WK pigeons that exhibited significant inter-breed differences in IMF content as well as FA and amino acid compositions in the breast muscles, and screened candidate genes influencing fat-related traits in squabs through gene ontology analysis and pathway analysis. By focusing on 6019 SNPs, which were located in genes with correct annotations and had the potential to induce changes in the encoded proteins, we identified 19 genes (ACAA1, ACAA2, ACACB, ACADS, ACAT1, ACOX3, ACSBG1, ACSBG2, ACSL1, ACSL4, ELOVL6, FADS1, FADS2, HACD4, HADH, HADHA, HADHB, MECR, OXSM) as candidate genes that could affect fat-related traits in squabs. They were significantly enriched in the pathways of FA metabolism, degradation, and biosynthesis (p < 0.05). Results from molecular docking analysis further revealed that three non-synonymous amino acid alterations, ACAA1(S357N), ACAA2(T234I), and ACACB(H1418N), could alter the non-bonding interactions between the enzymatic proteins and their substrates. Since ACAA1, ACAA2, and ACACB encode rate-limiting enzymes in FA synthesis and degradation, alterations in the enzyme–substrate binding affinity may subsequently affect the catalytic efficiency of enzymes. We suggested that SNPs in these three genes were worthy of further investigation into their roles in explaining the disparities in fat-related traits in squabs. Full article

FAD (fatty acid desaturase) and SAD (stearoyl-ACP desaturase) genes play key roles in the synthesis of fatty acids (FA) and determination of oil composition in flax (Linum usitatissimum L.). We searched for FAD and SAD genes in the most widely used flax genome of the variety CDC Bethune and three available long-read assembled flax genomes—YY5, 3896, and Atlant. We identified fifteen FAD2, six FAD3, and four SAD genes. Of all the identified genes, 24 were present in duplicated pairs. In most cases, two genes from a pair differed by a significant number of gene-specific SNPs (single nucleotide polymorphisms) or even InDels (insertions/deletions), except for FAD2a-1 and FAD2a-2, where only seven SNPs distinguished these genes. Errors were detected in the FAD2a-1, FAD2a-2, FAD3c-1, and FAD3d-2 sequences in the CDC Bethune genome assembly but not in the long-read genome assemblies. Expression analysis of the available transcriptomic data for different flax organs/tissues revealed that FAD2a-1, FAD2a-2, FAD3a, FAD3b, SAD3-1, and SAD3-2 were specifically expressed in embryos/seeds/capsules and could play a crucial role in the synthesis of FA in flax seeds. In contrast, FAD2b-1, FAD2b-2, SAD2-1, and SAD2-2 were highly expressed in all analyzed organs/tissues and could be involved in FA synthesis in whole flax plants. FAD2c-2, FAD2d-1, FAD3c-1, FAD3c-2, FAD3d-1, FAD3d-2, SAD3-1, and SAD3-2 showed differential expression under stress conditions—Fusarium oxysporum infection and drought. The obtained results are essential for research on molecular mechanisms of fatty acid synthesis, FAD and SAD editing, and marker-assisted and genomic selection for breeding flax varieties with a determined fatty acid composition of oil. Full article

The allo-tetraploid common carp encodes two duplicated fads2 genes (fads2a and fads2b) and two duplicated elovl5 genes (elovl5a and elovl5b). The coding SNPs (cSNPs) of these genes were reported to be significantly associated with the PUFA contents. Whether the promoter SNPs (pSNPs) were associated with the PUFA contents has not been reported yet. In this study, after sequencing the promoters of these four genes, we identified six pSNPs associated with the contents of PUFAs in common carp, including one elovl5a pSNP, one elovl5b pSNP, and four fads2b pSNPs. The pSNPs were predicted in the locations of transcriptional factor binding sites. Together with previously identified cSNPs in fads2b and elovl5b, the pSNPs and cSNPs of these two genes had the joint effects on the PUFA contents with higher explained percentage of phenotypic variation of the PUFA contents than single gene. The expression levels of both fads2a and fads2b were significantly positively correlated with the contents of six PUFAs. The fads2b pSNPs corresponding to higher fads2b expression levels were associated with higher PUFA contents. The pSNPs and cSNPs will be useful for the future selection breeding of common carp with higher PUFA contents. Full article

The increase in fetal requirements of long-chain polyunsaturated fatty acids (LCPUFAs) during pregnancy alters maternal fatty acid metabolism, and therefore, fatty acid desaturase (FADS) gene polymorphisms may change blood fatty acid composition or concentration differently during pregnancy. We investigated the relationship between a FADS1 single-nucleotide polymorphism (SNP) and maternal serum LCPUFA levels in Japanese pregnant women during the first and third trimesters and at delivery. Two hundred and fifty-three pregnant women were included, and fatty acid compositions of glycerophospholipids in serum (weight %) and the FADS1 SNP rs174547 (T/C) were analyzed. LCPUFAs, including arachidonic acid (ARA) and docosahexaenoic acid (DHA), significantly decreased from the first to the third trimester of pregnancy. Furthermore, DHA significantly decreased from the third trimester of pregnancy to delivery. At all gestational stages, linoleic acid (LA) and α-linolenic acid were significantly higher with the number of minor FADS1 SNP alleles, whereas γ-linolenic acid and ARA and the ARA/LA ratio were significantly lower. DHA was significantly lower with the number of minor FADS1 SNP alleles only in the third trimester and at delivery, suggesting that genotype effects become more obvious as pregnancy progresses. Full article

Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal system. Omega-3 (ω₃) fatty acids are polyunsaturated fatty acids (PUFAs) that are largely obtained from diet and have been speculated to decrease the inflammatory response that is involved in IBD; however, the causality of this association has not been established. A two-sample Mendelian randomization (MR) was used to assess genetic associations between 249 circulating metabolites measured in the UK Biobank as exposures and IBD as the outcome. The genome-wide association study summary level data for metabolite measurements and IBD were derived from large European ancestry cohorts. We observed ω₃ fatty acids as a significant protective association with IBD, with multiple modes of MR evidence replicated in three IBD summary genetic datasets. The instrumental variables that were involved in the causal association of ω₃ fatty acids with IBD highlighted an intronic SNP, rs174564, in FADS2, a protein engaged in the first step of alpha-linolenic acid desaturation leading to anti-inflammatory EPA and thence DHA production. A low ratio of ω₃ to ω₆ fatty acids was observed to be a causal risk factor, particularly for Crohn’s disease. ω₃ fatty acid supplementation may provide anti-inflammatory responses that are required to attenuate inflammation that is involved in IBD. Full article

Mycobacterium tuberculosis variant bovis (MBO) has one of the widest known mammalian host ranges, including humans. Despite the characterization of this pathogen in the 1800s and whole genome sequencing of a UK strain (AF2122) nearly two decades ago, the basis of its host specificity and pathogenicity remains poorly understood. Recent experimental calf infection studies show that MBO strain Ravenel (MBO Ravenel) is attenuated in the cattle host compared to other pathogenic strains of MBO. In the present study, experimental infections were performed to define attenuation. Whole genome sequencing was completed to identify regions of differences (RD) and single nucleotide polymorphisms (SNPs) to explain the observed attenuation. Comparative genomic analysis of MBO Ravenel against three pathogenic strains of MBO (strains AF2122-97, 10-7428, and 95-1315) was performed. Experimental infection studies on five calves each, with either MBO Ravenel or 95-1315, revealed no visible lesions in all five animals in the Ravenel group despite robust IFN-γ responses. Out of 486 polymorphisms in the present analysis, 173 were unique to MBO Ravenel among the strains compared. A high-confidence subset of nine unique SNPs were missense mutations in genes with annotated functions impacting two major MBO survival and virulence pathways: (1) Cell wall synthesis & transport [espH (A103T), mmpL8 (V888I), aftB (H484Y), eccC₅ (T507M), rpfB (E263G)], and (2) Lipid metabolism & respiration [mycP₁(T125I), pks5 (G455S), fadD29 (N231S), fadE29 (V360G)]. These substitutions likely contribute to the observed attenuation. Results from experimental calf infections and the functional attributions of polymorphic loci on the genome of MBO Ravenel provide new insights into the strain’s genotype-disease phenotype associations. Full article