Search Results (88)

Nervonic acid (NA, C24:1 Δ15) is a vital extra-long-chain monounsaturated fatty acid essential for neural development, myelin sheath formation, and neurological health. As the most abundant natural source of NA, Malania oleifera Chun & S.K.Lee has become a key model for studying NA biosynthesis and regulation. This review systematically summarizes the metabolic pathways of nervonic acid biosynthesis in M. oleifera, including plastidial de novo fatty acid synthesis, endoplasmic reticulum (ER)-based very-long-chain fatty acid elongation, and Δ15 desaturation. We focus on the catalytic mechanisms and rate-limiting roles of the elongase complex (KCS, KCR, HCD, ECR) and Δ15 desaturase. Additionally, we integrate recent multi-omics data to analyze key enzyme KCS gene families, their phylogenetic relationships, and syntenic distribution patterns. Furthermore, transcriptional regulatory networks (MYB, bZIP, WRI1, ABI3, FUS3) and epigenetic regulation underlying NA accumulation are also discussed. Finally, we highlight advances, challenges, and prospects in metabolic engineering and synthetic biology for sustainable NA production. This review provides a theoretical basis for the conservation, molecular breeding, and biotechnological utilization of M. oleifera. Full article

Background/Objectives: Chemosymbiotic bivalves play a fundamental role in deep-sea cold seep and hydrothermal vent ecosystems, where essential long-chain polyunsaturated fatty acids (LC-PUFAs) are scarce. Whether these bivalves retain the capacity for endogenous PUFA synthesis remains poorly understood. Here, we investigated the PUFA biosynthetic capacity of two dominant chemosymbiotic bivalves from the Haima cold seep—the mussel Gigantidas haimaensis and the clam Archivesica marissinica. Methods: Genome and transcriptome assembly revealed three fatty acid desaturase (Fad) genes per species, which phylogenetically clustered into Δ5 (GhFads1, GhFads2; AmFads1, AmFads2) and Δ6/8 (GhFads3, AmFads3) clades, with lineage-specific duplications within the Δ5 clade. Functional assays were performed in yeast to characterize the activity of these enzymes. Results:Both Fads3 enzymes (Δ6/8 clade) convert C20:3n-6 and C20:4n-3 into C20:4n-6 and C20:5n-3, respectively, exhibiting Δ8-desaturase activity. Notably, Δ5-clade isoforms showed divergent substrate specificities: GhFads2 and AmFads1 functioned as classical Δ5-desaturases on PUFA substrates, whereas GhFads1 and AmFads2 specifically desaturated the bacterial monounsaturated fatty acid (MUFA) C18:1n-7 to produce C18:2n PUFAs. Conclusions: Together, our results reveal that cold-seep bivalves retain endogenous LC-PUFA biosynthetic capacity and have evolved duplicated Δ5-desaturases with novel regioselectivity toward bacterial MUFAs, likely representing an adaptive membrane modification for survival under extreme deep-sea conditions. Full article

Background/Objectives: Precision nutrition informed by genetic profiling has been proposed to improve public health outcomes; however, long-term, community-based evidence remains limited. This study evaluated the long-term health and economic impacts of the Sakado Folate Project. Methods: Since 2006, residents participating in the Sakado Folate Project received gene-guided nutritional counseling focused on folate intake and related lifestyle factors. Target genes included methylenetetrahydrofolate reductase (MTHFR), angiotensinogen (AGT), adrenoreceptor B3 (ADRB3), and uncoupling protein 1 (UCP1); Δ5-fatty acid desaturase (FADS1) was incorporated later. Biochemical markers, genetic polymorphisms, and health indicators were monitored longitudinally. Population-level health outcomes and per-capita medical expenditure data were compared with regional and national statistics. Results: In program participants (n = 888), folate status and biochemical indicators improved: 76.1% achieved the serum folate target (≥9.5 ng/mL) and 55.3% achieved the serum total homocysteine target (≤7 μmol/L). Healthier lifestyle behaviors were observed across 99,565 Sakado residents, with the city recording the highest proportion of individuals actively attempting lifestyle improvement (31%) of all districts in the region. Disease prevalence was lower in Sakado City than in Saitama Prefecture overall, at standardized prevalence ratios of 52% for stroke and 86% for cerebral infarction. Per-capita medical expenditure was also lower in Sakado City (¥337,800) than the national average (¥392,044) in 2021. Conclusions: Long-term implementation of a community-based, gene-guided nutritional intervention may improve population health outcomes and reduce healthcare expenditures. Integrating nutrigenomics into public health strategies alongside community education and food environment improvements may contribute to sustainable healthcare systems in aging societies. Full article

Ricinus communis is the primary commercial source of ricinoleic acid (RA), a hydroxy fatty acid (HFA) synthesized by the fatty acid hydroxylase FAH12, which evolved from the Δ12-oleate desaturase FAD2. However, the evolutionary origins and diversification mechanisms of FAH12 across HFA-producing plants remain poorly understood. Here, we performed a comprehensive cross-species analysis of FAH12 and FAD2 homologs by integrating sequence analysis, structural modeling, phylogenetic reconstruction, and transcriptomic profiling. Across all currently available HFA-producing plant lineages, we found that amino acid substitutions associated with hydroxylase activity exhibit strong lineage-specific patterns rather than universal conservation, indicating multiple evolutionary solutions to catalytic divergence. Phylogenetic and synteny analyses further suggest that FAH12 arose independently from ancestral FAD2 duplications in distinct plant lineages, supporting a model of recurrent independent neofunctionalization. Transcriptomic and qRT-PCR analyses reveal that FAH12 exhibits a highly specialized endosperm-preferential expression pattern and is embedded within a regulatory network that is partially decoupled from that of FAD2. Together, these findings demonstrate that FAH12 evolution is driven by recurrent independent origins coupled with transcriptional specialization, providing a framework linking structural variation, evolutionary history, and regulatory divergence for understanding and engineering hydroxy fatty acid biosynthesis in plants. Full article

This study explored the physiological responses and gene expression profiles of the Manila clam (Ruditapes philippinarum) and the hard clam (Mercenaria mercenaria) under heat and hyposaline stress. Experimental conditions involved increasing the temperature from 25 °C to 35 °C and decreasing salinity from 25 ppt to 15 ppt over a 6 h acclimation period, followed by 72 h exposure. Key physiological and immune indicators, including filtration rate, oxygen consumption rate, ammonia excretion rate, and the expression of related genes, were measured. Under heat stress, R. philippinarum exhibited higher filtration, oxygen consumption, and ammonia excretion rates than M. mercenaria at most sampling time points. The expression of fatty acid desaturase (Δ6FAD) and heat shock protein (HSP70) genes increased and then decreased for both species, whereas superoxide dismutase (Cu/Zn SOD) gene expression gradually decreased over time. Furthermore, the expression levels of all three genes were generally significantly higher in M. mercenaria compared to R. philippinarum. Under hyposaline stress, R. philippinarum exhibited significantly higher filtration, oxygen consumption, and ammonia excretion rates than M. mercenaria between 24 h and 72 h. Expression levels of the Na⁺-K⁺-ATPase (NKAα), HSP70, and Cu/Zn SOD genes remained higher in M. mercenaria compared to R. philippinarum. Overall, the present study indicates that M. mercenaria maintains relative stability and R. philippinarum exhibits greater physiological fluctuation under both heat and hyposaline stress. This study highlights bivalve species-specific responses to environmental stressors and provides valuable insights for aquaculture planning and ecological management in different environmental regions, particularly in the context of global climate change. Full article

Oleaginous microorganisms usually accumulate large amounts of lipids under nitrogen limitation and in a carbon-abundant environment. However, how cells sense changes in nitrogen and carbon levels in the culture medium remains a research hotspot. Previous studies have found that the target of rapamycin complex 1 (TORC1) plays a core role in lipid accumulation in oleaginous microorganisms. The results of the Kog1 (the member proteins of TORC1) knockout strain constructed earlier by our group showed that the Kog1 negatively regulated lipid accumulation in the oleaginous fungus Mucor circinelloides. In this study, transcriptomic analysis of the knockout and control strains under nitrogen-limited and nitrogen-sufficient culture was carried out to investigate significant differences in lipid accumulation. Kog1 knockout led to a significant decrease in cell dry weight and an increase in lipid content in M. circinelloides. The transcriptomic results showed that genes encoding the glyoxylic acid cycle and genes encoding acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and Δ9 desaturase in lipid synthesis were upregulated to varying degrees under both conditions, indicating enhanced lipid metabolism that ultimately led to increased lipid accumulation. The knockout of the Kog1 gene also activated the pyruvate–acetaldehyde–acetate metabolic axis and significantly modified the branched-chain amino acid metabolic network, suggesting that Kog1 knockout reprograms the pathway of branched-chain amino acid synthesis and degradation, shifting the carbon flux from amino acid metabolism to acetyl-CoA accumulation. In addition, the gene encoding the SSK1p transcription factor, which participates in the nutrient stress response, was upregulated 41.9- and 51.9-fold in the Kog1 knockout strain compared with the control strain under nitrogen-limited and nitrogen-sufficient conditions, respectively. Full article

The search for sustainable alternatives to fishmeal (FM) in aquafeeds represents a major challenge for modern aquaculture. This study evaluated the effects of replacing 35% of FM with defatted Hermetia illucens larvae meal (HIM35) in diets of gilthead seabream (Sparus aurata) reared under full-scale commercial offshore farming conditions. Fillet nutritional quality, fatty acid and amino acid profiles, mineral composition, and microbiological stability during refrigerated storage were assessed. Dietary HIM35 significantly modified the fatty acid profile, increasing saturated fatty acids, particularly lauric and myristic acids, and n-6 polyunsaturated fatty acids. Despite reductions in eicosapentaenoic and docosahexaenoic acids (EPA and DHA), total PUFA and lipid health indices remained within recommended ranges and EPA + DHA levels were above 8%, supporting both fillet nutritional value and fish physiological requirements. Enzymatic indices based on product-to-precursor fatty acid ratios suggested reduced Δ5 + Δ6-desaturase activity. The amino acid profile showed increases in selected essential and non-essential amino acids, while overall protein quality was preserved. HIM35 fillets showed lower sodium and higher zinc contents, whereas increased aluminum levels warrant further investigation. Microbiological analyses confirmed the absence of foodborne pathogens and no effects on spoilage dynamics. Overall, HIM35 represents a safe and effective partial replacement for FM supporting sustainable aquafeed strategies. Full article

Grape pomace is an agri-industrial by-product rich in fatty acids with the potential to be used in diets for goats and increase the nutraceutical properties of milk. This study aimed to investigate the effect of incorporating dehydrated grape pomace (DGP) into the diets of Saanen goats on the composition, fatty acid profile, nutritional indices of fatty acids, and antioxidant capacity of their milk. Eight multiparous Saanen goats, averaging approximately four years of age and weighing 41.2 ± 15.7 kg, were used in a double Latin square (4 × 4) design. Diets were formulated with increasing levels of grape pomace (0, 90, 150, and 210 g/kg Dry Matter—DM), replacing cactus. The data underwent analysis of variance using GLM procedure and regression analysis (both linear and quadratic) using REG procedure at a significant level of 5%. The concentration of C18:2 n-6 cis and C18:3 n-3 increased (+20.1 and +15.5%, respectively) with the grape pomace inclusion. There was a reduction in the atherogenic (−24.0%) and thrombogenic (−9.9%) indices of goat milk with the increase in DGP levels. There was a reduction in de novo fatty acids (−10.5%), Δ⁻⁹ desaturase of C14 (−21.8%) and C18 (−9.5%) indexes with the highest level of DGP. There was a quadratic effect for Ferric Reducing Antioxidant Power (FRAP) and a linear effect for phenolic compounds (PC), where the highest values were observed at the estimated levels of 160 g/kg and 210 g/kg DM, respectively. Supplementing dairy goats’ diets with dehydrated grape pomace up to 210 g/kg dry matter enhances the fatty acid profile and nutritional indices of fatty acids of Saanen goat milk without altering its basic composition. As grape production is prevalent in low rainfall regions, pomace may provide an alternative feed in areas with forage production constraints. Additionally, grape residue could establish a link between the wine and dairy sectors for cheese production, expanding markets for farmers. Full article

Palmitoleic acid (POA; 16:1 n-7 or cis-9 16:1) is a bioactive monounsaturated fatty acid (FA) with emerging metabolic and skin-health relevance, yet conventional botanical and animal sources provide limited and variable levels. Here we report on the development of a high-yield POA product platform in the heterotrophic microalga Prototheca moriformis through targeted genetic engineering. A Δ9-fatty acid desaturase from Macadamia integrifolia (MiSAD1618) was integrated using a phosphite-based selection system. Primary screening identified stable transformants producing up to 54% POA of total fatty acids, compared to 0.8% in the parental strain. In 1 L shake-flask cultivation, POA reached up to 58.2% of total fatty acids. In a 1 L fed-batch fermentation, the engineered strain accumulated 47.8 g/L of lipids with 43.5% POA after 96 h of fermentation, corresponding to 20.8 g/L of POA. GC–MS analysis of 4,4-dimethyloxazoline (DMOX) derivatives confirmed that the major 16:1 isomer was 16:1 n-7 (Δ9). Together, these results establish P. moriformis as a scalable fermentation platform for producing POA-rich oil and highlight its potential as an efficient alternative source of POA, providing a foundation for further strain and process optimization toward commercial production. Full article

Wild seeds constitute a taxonomically diverse and underexplored reservoir of C18-series bioactive fatty acids (BFAs) with significant nutritional, biomedical, and industrial relevance. This review integrates current knowledge on their lipid composition, metabolic architecture, and potential applications. Numerous wild taxa accumulate high levels of oleic, linoleic, α-linolenic, γ-linolenic, and stearidonic acids, while others synthesise structurally specialised compounds such as punicic, petroselinic, and sciadonic acids. These FAs, together with tocopherols, phytosterols, and phenolics, underpin antioxidant, anti-inflammatory, immunomodulatory, and cardiometabolic effects supported by in vitro and in vivo evidence. The occurrence of these unusual lipids reflects lineage-specific modulation of plastidial and endoplasmic-reticulum pathways, including differential activities of SAD, FAD2/3, Δ6- and Δ5-desaturases, elongases, and acyl-editing enzymes that determine the final acyl-CoA and TAG pools. Wild seed oils show strong potential for translation into functional foods, targeted nutraceuticals, pharmacologically relevant lipid formulations, cosmetic ingredients, and bio-based materials. However, their exploitation is constrained by ecological sustainability, oxidative instability of PUFA-rich matrices, antinutritional constituents, and regulatory requirements for novel lipid sources. This review positions wild seeds as high-value, underused lipid resources with direct relevance to health and sustainability. It underscores their potential to enhance nutritional security and offer alternatives to conventional oil crops. Full article

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) has been linked to dietary fat quality and polyunsaturated fatty-acid metabolism. We evaluated whether dietary n-6 fatty-acid intake, serum dihomo-γ-linolenic acid (DGLA), and desaturase-based indices for Δ5-desaturase (D5D) and Δ6-desaturase (D6D) are associated with MASLD. Methods: We conducted a cross-sectional analysis within the HOZUGAWA health checkup cohort in Japan (n = 289; 100 MASLD, 189 non-MASLD). Participants underwent hepatic ultrasonography, dietary assessment using the Brief Self-Administered Diet History Questionnaire, and fasting serum metabolomics by gas chromatography–mass spectrometry with solid-phase dehydration derivatization. Enzyme indices were defined as the D5D index = arachidonic acid/DGLA and the D6D proxy index = DGLA/linoleic acid (hereafter referred to as the D6D index) because γ-linolenic acid was not measured. Natural-log-transformed D5D index, D6D index, DGLA, and total dietary n-6 fatty-acid intake were entered into multivariable logistic regression models for MASLD adjusted for age, sex, BMI, alcohol intake, and total energy. Results: Compared with non-MASLD, MASLD showed higher serum DGLA, lower D5D index, and higher D6D index (all p ≤ 0.005), with no between-group differences in total energy intake, linoleic acid, total polyunsaturated fatty acids, or total dietary n-6 fatty-acid intake. Higher ln D5D was independently associated with lower odds of MASLD (OR 0.62, 95% CI 0.42–0.86), whereas higher ln D6D index (OR 1.42, 95% CI 1.04–1.95) and ln DGLA (OR 1.62, 95% CI 1.13–2.43) were each positively associated. Total dietary n-6 fatty-acid intake was not independently associated with MASLD. Conclusions: In this Japanese health examination cohort, an imbalance in estimated desaturase activities—lower D5D index and higher D6D index—together with higher serum DGLA was independently associated with MASLD, whereas n-6 intake showed no group difference or independent association. These findings suggest that enzyme-linked endogenous n-6 metabolic status may be more closely related to the MASLD phenotype than intake quantity alone. Full article

Considering the effects of increasing heat waves already underway, especially in several areas of the Mediterranean region, the study of the effect of temperature on the qualitative yield of hemp oil becomes necessary. Given this, an experiment was conducted in order to evaluate the effect of temperature during the grain-filling period on fatty acid accumulation and composition in hemp seed, comparing two locations with different temperature regimes, two years, two sowing times and two monoecious hemp varieties, characterized by different earliness. The accumulation of different fatty acids in hemp seeds at maturity seems to depend on the genetic background of the two genotypes studied. However, high temperatures also affect the activity of desaturase Δ12 and Δ15, which are responsible for the production of polyunsaturated fatty acids, in particular if greater than an 18 °C minimum night temperature and 30 °C maximum daily temperature, respectively. This result makes it possible to orient, even if partially, the qualitative characteristics of hemp oil for different uses, by identifying the suitable cultivation environment. Considering the Mediterranean area, hilly and foothill environments would favor the percentage of polyunsaturated fatty acid in the oil, with an improvement of the n-6/n-3 ratio, while the plain and warmer area, characterized by heat stress during the grain-filling period, would give an oil with an increased percentage of monounsaturated acids to the detriment of polyunsaturated fatty acid. Full article

Imbalance in fatty acid (FA) metabolism is a critical factor in the development of type 2 diabetes (T2D). This study examined fatty acid composition and desaturase activities in the liver and spinal cord of male Zucker diabetic fatty (ZDF) rats, a genetic model of T2D. Heterozygous lean ZDF fa/+ animals served as controls, while homozygous obese ZDF fa/fa animals represented the diabetic group. FA profiles were determined by gas chromatography, and the activities of Δ5-desaturase (FADS1), Δ6-desaturase (FADS2), Δ9-desaturase (SCD1), and elongase of very long-chain fatty acids (ELOVL) were estimated. T2D rats displayed significantly elevated levels of monounsaturated fatty acids (MUFAs) and increased SCD1 activity in both the liver and spinal cord. In contrast, polyunsaturated fatty acids (PUFAs), particularly arachidonic acid (AA, C20:4 n-6), were reduced. Since AA plays a fundamental role in neuronal membrane structure and signaling pathways, these alterations have particular relevance to nervous system function. Tissue-specific alterations further suggested impaired FADS1 activity in the liver and reduced elongase/FADS2 activity in the spinal cord. These findings suggest that desaturase imbalance and FA remodeling in the spinal cord might represent characteristic features of T2D and that altered FA metabolism within the nervous system may potentially serve as an early indicator of neuropathy or a predictor of increased susceptibility to diabetes-related complications. Full article

Astaxanthin plays a vital role in pigmentation, immune function, reproduction, and antioxidation in aquatic species. To clarify the molecular mechanism of astaxanthin utilization in Exopalaemon carinicauda (E. carinicauda), we conducted a comparative transcriptome analysis on the intestine, hepatopancreas, and muscle of E. carinicauda, fed with an astaxanthin diet and a normal diet. A total of 144 differentially expressed genes (DEGs) were identified in three tissues between the two groups. Genes related to absorption and transport, such as LDLR and the vitellogenin receptor, were upregulated in the intestine after astaxanthin supplementation, while the ileal sodium/bile acid cotransporter-like gene was downregulated. In the hepatopancreas, genes involved in lipid storage and degradation were significantly altered at the transcriptional level, including Kruppel 1-like, ACSBG2, δ(7)-sterol 5(6)-desaturase-like, and PNLIPRP2. In the muscle, the expression of the FABP gene was significantly upregulated, while several actin and troponin genes were significantly downregulated. Furthermore, GSEA analysis on the transcriptomes of three tissues revealed that astaxanthin supplementation influenced the expression of genes related to antioxidation and growth, indicating that astaxanthin may have a positive impact on the growth, development, and resistance of organisms. The data from this research provide valuable insights into elucidating the molecular mechanisms underlying astaxanthin absorption and metabolism and also offer guidance for the application of astaxanthin in the aquaculture of economically important crustaceans. Full article

Background/Objectives: This study investigates the effects of a high-fat diet (HFD) during pregnancy and lactation on maternal and offspring health, focusing on behavioral, metabolic, and fatty acid composition outcomes in a rat model. Methods: Twelve female Sprague–Dawley rats were fed either a control diet, CD (n = 6), or HFD (n = 6) for 12 weeks, encompassing mating, gestation, and lactation periods (18 weeks). Anxiety-like behavior, maternal behavior, depression-like behavior, and social play were studied. Post mortem, the liver function, hepatic steatosis, and fatty acid composition (erythrocytes, liver, adipose tissue) were evaluated. In regard to desaturase enzymes (Δ-6D and Δ-5D), liver activity, protein mass, and gene expression (RT-PCR) were analyzed. Additionally, gene expression of PPAR-α, ACOX, CPT1-α, SREBP-1c, ACC, and FAS was assessed. Statistical analysis was performed using Student’s t-test, mean ± SD (p < 0.05). Results: The HFD significantly increased maternal weight and anxiety-like behavior while reducing social interactions exclusively in male offspring (p < 0.05). It also led to a significant decrease in the synthesis and content of n-3 PUFAs in the analyzed tissues, induced hepatic steatosis, and upregulated the expression of pro-lipogenic genes in the maternal liver. Conclusions: These findings suggest that long-term HFD consumption alters tissue fatty acid composition, disrupts metabolic homeostasis, and contributes to behavioral changes, increasing anxiety-like behaviors in pregnant dams and reducing social interactions in male offspring. Overall, this study provides further insight into the detrimental effects of HFD consumption during the perinatal period. Full article