• Journal of Applied Biological Chemistry
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• v.44 no.1
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• pp.6-11
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• 2001

An ${\omega}-3$ fatty acid desaturase gene which is involved in de novo synthesis of -Iinolenate was isolated from cDNA library of Perilla frutescens. A cDNA library was constructed with mRNA extracted from perilla seeds of 12 DAF. The cDNA clone consisting of 1317-bp open reading frame encoding 438 amino acids with a relative MW of 50kDa, was isolated and showed 65-83% similarities to other known genes. This cDNA is deduced to encode a plastidal ${\omega}-3$ fatty acid desaturase based on the fact that it has higher homology to plastidal ones than to microsomal ones and its N-terminal sequence shares several characteristics of transit peptides of chloroplast proteins. Southern blot analysis of genomic DNA indicated that more than one gene or alleles for ${\omega}-3$ fatty acid desaturase are present in the genome of perilla. Northern blot analysis showed that the ${\omega}-3$ fatty acid desaturase gene is mainly revealed in early developing seeds and has different expression patterns depending on tissue types compared to the microsomal ones.

• Korean Journal of Medicinal Crop Science
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• v.12 no.5
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• pp.424-427
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• 2004

Microsomal ${\omega}-3$ fatty acid desaturase (FAD3) is an essential enzyme in the production of the n-3 polyunsaturated fatty acid ${\alpha}-linolenic$ acid during the seed developing stage. To understand the regulatory mechanism of the gene encoding the ${\omega}-3$ fatty acid desaturase, a genomic fragment corresponding to the previously isolated perilla seed PfFAD3 cDNA was amplified from perilla (Perilla frutescens Britt) by GenomeWalker PCR. Sequence analysis of the fragment provided with identification of a 1485-bp 5'-upstream region and a 241-bp intron in the open reading frame. To determine the tissue-specificity of the PfFAD3 gene expression, the 5'-upstream region was fused to the ${\beta}-glucuronidase$ (GUS) gene and incorporated into Arabidopsis thaliana. Histochemical assay of the transgenic plants showed that GUS expression was restricted to seed and pollen, showing that PfFAD3 gene was exclusively expressed in those tissues.

• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.93-97
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• 1997

For the molecular genetic study of cold tolerance mechanism in plants, a cDNA encoding fatty acid desaturase (fad3), converting linoleic acid (18:2, $\omega$-6) to linolenic acid (18:3, $\omega$-3), was isolated from $\lambda$ZAPII Arabidopsis thaliana cDNA expression library by plaque hybridization using fad3 cDNA probe derived from Brassica napus. A 1.8 kb-EcoRI fragment from a lambda clone showing a strong positive hybridization signal was subcloned into pGEM7 and analyzed for its nucleotide sequence. From deduced amino acid sequences, the fad3 gene was revealed to have an open reading frame(ORF) consisting of 386 amino acids with a molecular mass of 44,075 Da. The fad3 gene was compared to chloroplast $\omega$-3 fatty acid desaturase (fad7) and endoplasmic reticulum Δ12 fatty acid desaturase (fad2) to show 70% and 58% amino acid sequence homology, respectively, Especially, amino acids of internal (82 to 151) and carboxy terminal (276 to 333) regions were highly conserved, implying their requisite role for enzymatic functioning of fatty acid desaturases. IPTG-induced fad3 cDNA expression in E. coli cells was suggested to be toxic to bacterial growth.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1413-1421
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• 2013

The marine microalga Isochrysis sphaerica is rich in the very-long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (EPA, $C20:5{\omega}-3$) and docosahexaenoic acid (DHA, $C22:6{\omega}-3$) that are important to human health. Here, we report a functional characterization of a ${\Delta}4$-fatty acid desaturase gene (FAD4) from I. sphaerica. IsFAD4 contains a 1,284 bp open reading frame encoding a 427 amino acid polypeptide. The deduced amino sequence comprises three conserved histidine motifs and a cytochrome b5 domain at its N-terminus. Phylogenetic analysis indicated that IsFad4 formed a unique Isochrysis clade distinct from the counterparts of other eukaryotes. Heterologous expression of IsFAD4 in Pichia pastoris showed that IsFad4 was able to desaturate docosapentaenoic acid (DPA) to form DHA, and the rate of converting DPA to DHA was 79.8%. These results throw light on the potential industrial production of specific polyunsaturated fatty acids through IsFAD4 transgenic yeast or oil crops.

• Journal of Life Science
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• v.28 no.8
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• pp.945-954
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• 2018

Omega-3 polyunsaturated fatty acids (${\omega}3$-fatty acid) have been found to possess anticancer properties in a variety of cancer cell lines and animal models, but their effects in human tongue squamous cell carcinomas (SCCs) remain unclear. This study was designed to examine the effect of ${\omega}3$-fatty acid desaturase (fat-1) gene expression on invasion and tumorigenicity in human tongue SCC cells and the molecular mechanism of its action. Docosahexaenoic acid (DHA) treatment inhibited in vitro invasion in a dose-dependent manner. In zymography, matrix metalloproteinase-9 (MMP-9) and Matrix metallopeptidase-2 (MMP-2) activities were reduced, and MMP-9 and MMP-2 promoter activities were inhibited by the DHA treatment. In addition, cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) promoter reporter activities were inhibited in SCC-4 and SCC-9 cells after the DHA treatment. To investigate the effect of a high level of endogenous ${\omega}3$ fatty acids, a stable SCC-9 cell line expressing the ${\omega}3$-desaturase gene (fSCC-9sc) was generated. The growth rate and colony-forming capacity of fSCC-9sc were remarkably decreased as compared with those of fSCC-9cc. Likewise, the tumor size and volume of fSCC-9sc implanted into nude mice were significantly inhibited, with increases in the cell death index. Furthermore, a transwell chamber invasion assay showed a reduction in cell invasion of the fSCC-9sc lines when compared with that of the fSCC-9cc line. These findings suggested that fat-1 gene expression inhibited tumorigenicity, as well as invasion in human tongue SCC cells. Thus, utilization of ${\omega}3$ fatty acids may represent a promising therapeutic approach for chemoprevention and the treatment of human tongue SCCs.

• BMB Reports
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• v.29 no.4
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• pp.308-313
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• 1996

An 1.4 kb of the fad3 cDNA encoding microsomal linoleic acid desaturase catalyzing the conversion of linoleic acid (18:2, ${\omega}-6$) to linolenic acid (18:2, ${\omega}-3$) was introduced into tobacco plants by the Agrobacterium-mediated plant transformation, Among the transgenic tobacco plants conferring kanamycin resistance, five transformants showing increment in unsaturated fatty acid contents were selected and further analyzed for the transgenecity, In genomic Southern blot analyses, copy numbers of the integrated fad3 DNA in chromosomal DNA of the five transgenic tobacco plants were varied among the transgenic lines. By Northern blot analyses, the abundancy of the fad3 mRNA transcript directed by Cauliflower Mosaic Virus 35S promoter was consistent with the relative copy number of the fad3 DNA integrated in the chromosome of transgenic tobacco plants. When compared with the wild type, accumulation of linolenic acid in transgenic tobacco roots was elevated 3.7- to 4.7-fold showing a corresponding decrease in the linoleic acid contents; however, slight increments for linolenic acid were noticed in transgenic leaf tissues. These results indicated that the elevated level of fad3 expression is achieved in transgenic tobacco plants.

• Journal of Crop Science and Biotechnology
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• v.10 no.4
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• pp.201-210
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• 2007

Soybean [Glycine max(L.) Merr.] oil is versatile and used in many products. Modifying the fatty acid profile would make soy oil more functional in food and other products. The ideal oil with the most end uses would have saturates(palmitic + stearic acids) reduced from 15 to < 7%, oleic acid increased from 23 to > 55%, and linolenic acid reduced from 8 to < 3%. Reduced palmitic acid(16:0) is conditioned by three or more recessive alleles at the Fap locus. QTLs for reduced palmitic acid have mapped to linkage groups(LGs) A1, A2, B2, H, J, and L. Genes at the Fad locus control oleic acid content(18:1). Six QTLs($R^2$=4-25%) for increased 18:1 in N00-3350(50 to 60% 18:1) explained four to 25% of the phenotypic variation. M23, a Japanese mutant line with 40 to 50% 18:1 is controlled by a single recessive gene, ol. A candidate gene for FAD2-1A can be used in marker-assisted breeding for high 18:1 from M23. Low linolenic acid(18:3) is desirable in soy oil to reduce hydrogenation and trans-fat accumulation. Three independent recessive genes affecting omega-3 fatty acid desaturase enzyme activity are responsible for the lower 18:3 content in soybeans. Linolenic acid can be reduced from 8 to about 4, 2, and 1% from copies of one, two, or three genes, respectively. Using a candidate gene approach perfect markers for three microsomal omega-3 desaturase genes have been characterized and can readily be used in for marker assisted selection in breeding for low 18:3.

• Animal Bioscience
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• v.34 no.4
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• pp.662-669
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• 2021

Objective: Effects of linseed oil (LO) supplementation on the fat content and fatty acid profile of breast meat, and the expression of three genes in the liver, breast muscle and fat tissues of commercial 154-day-old hybrid male turkeys were investigated. Methods: The animals in the control group were fed a commercially available feed and received no LO supplementation (n = 70), whereas animals in the LO group (n = 70) were fed the same basic diet supplemented with LO (day 15 to 21, 0.5%; day 22 to 112, 1%). The effect of dietary LO supplementation on fatty acid composition of breast muscle was examined by gas chromatography, and the expression of fatty acid desaturase 2 (FADS2), peroxisome proliferator activated receptor gamma (PPARγ), and insulin-like growth factor 1 (IGF1) genes was analysed by means of quantitative reverse transcription polymerase chain reaction. Results: The LO supplementation affected the fatty acid composition of breast muscle. Hepatic FADS2 levels were considerably lower (p<0.001), while adipose tissue expression was higher (p<0.05) in the control compared to the LO group. The PPARγ expression was lower (p<0.05), whereas IGF1 was higher (p<0.05) in the fat of control animals. There were no significant (p>0.05) differences in FADS2, PPARγ, and IGF1 gene expressions of breast muscle; however, omega-6/omega-3 ratio of breast muscle substantially decreased (p<0.001) in the LO group compared to control. Conclusion: Fatty acid composition of breast meat was positively influenced by LO supplementation without deterioration of fattening parameters. Remarkably, increased FADS2 expression in the liver of LO supplemented animals was associated with a significantly decreased omega-6/omega-3 ratio, providing a potentially healthier meat product for human consumption. Increased PPARγ expression in fat tissue of the LO group was not associated with fat content of muscle, whereas a decreased IGF1 expression in fat tissue was associated with a trend of decreasing fat content in muscle of the experimental LO group.

• Plant Biotechnology Reports
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• v.4 no.3
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• pp.185-192
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• 2010

The Arabidopsis ${\omega}$-3 fatty acid desaturase (AtFAD7) catalyzes the synthesis of trienoic fatty acids (TA). A transgenic tobacco line, T15, was produced by a sense AtFAD7 construct and showed a cosuppression-like phenotype, namely extremely low TA levels. The sequence similarity between AtFAD7 and a tobacco ortholog gene, NtFAD7, was moderate (about 69%) in the coding sequences. AtFAD7 siRNAs accumulated at a high level, and both AtFAD7 and NtFAD7 mRNAs are degraded in T15 plants. The low-TA phenotype in T15 was dependent on a tobacco RNA-dependent RNA polymerase6 (NtRDR6). We also produced tobacco RNAi plants targeting AtFAD7 gene sequences. The AtFAD7 siRNA level was trace, which was associated with a slight reduction in leaf TA level. Unexpectedly, this RNAi plant showed an increased NtFAD7 transcript level. To investigate the effect of translational inhibition on stability of the NtFAD7 mRNAs, leaves of the wild-type tobacco plants were treated with a translational inhibitor, cycloheximide. The level of NtFAD7 mRNAs significantly increased after cycloheximde treatment. These results suggest that the translational inhibition by low levels of AtFAD7 siRNAs or by cycloheximide increased stability of NtFAD7 mRNA. The degree of silencing by an RNAi construct targeting the AtFAD7 gene was increased by co-existence of the AtFAD7 transgene, where NtRDR6-dependent amplification of siRNAs occurred. These results indicate that NtRDR6 can emphasize silencing effects in both cosuppression and RNAi.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2000.10a
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• pp.63.1-63
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• 2000