摘要:
Engineered strains of the oleaginous yeast Yarrowia lipolytica capable of producing greater than 10% arachidonic acid (ARA, an ω-6 polyunsaturated fatty acid) in the total oil fraction are described. These strains comprise various chimeric genes expressing heterologous desaturases, elongases and acyltransferases, and optionally comprise various native desaturase and acyltransferase knockouts to enable synthesis and high accumulation of ARA. Production host cells are claimed, as are methods for producing ARA within said host cells.
摘要:
The present invention relates to methods for the production of ω-3 and/or ω-6 fatty acids in oleaginous yeast. Thus, desaturases and elongases able to catalyze the conversion of linoleic acid (LA) to γ-linolenic acid (GLA); α-linoleic acid (ALA) to stearidonic acid (STA); GLA to dihomo-γ-linoleic acid (DGLA); STA to eicosatetraenoic acid (ETA); DGLA to arachidonic acid (ARA); ETA to eicosapentaenoic acid (EPA); DGLA to ETA; EPA to docosapentaenoic acid (DPA); and ARA to EPA have been introduced into the genome of Yarrowia for synthesis of ARA and EPA.
摘要:
Transgenic soybean seed having increased total fatty acid content of at least 10% and altered fatty acid profiles when compared to the total fatty acid content of non-transgenic, null segregant soybean seed are described. DGAT genes from Yarrowia Lipolytica are used to achieve the increase in seed storage lipids.
摘要:
Two acyltransferases are provided, suitable for use in the manufacture of microbial oils enriched in omega fatty acids in oleaginous yeast (e.g., Yarrowia lipolytica). Specifically, the genes encoding phophatidylcholine-diacylglycerol acyltransferase (PDAT) and diacylglycerol acyltransferase (DGAT2) have been isolated from Y. lipolytica. These genes encode enzymes that participate in the terminal step in oil biosynthesis in yeast. Each is expected to play a key role in altering the quantity of polyunsaturated fatty acids produced in oils of oleaginous yeasts.
摘要:
The present invention relates to fungal Δ12 desaturases (responsible for conversion of oleic acid to linoleic acid (18:2, LA)) and Δ15 fatty acid desaturases (responsible for conversion of LA to α-linolenic acid (18:3, ALA)). Amino acid motifs diagnostic of Δ12 desaturases and Δ15 desaturases are also provided. Methods of altering enzyme specificity towards Δ12 desaturation or towards Δ15 desaturation and/or increasing production of specific ω-3 and ω-6 fatty acids by over-expression of the fungal desaturases are also described.
摘要:
This invention relates to methods of controlling gene silencing using site-specific recombination. A variety of constructs are provided which are useful for conditional or regulated gene silencing in plants, comprising a suite of constitutive, inducible, tissue-specific or developmental stage-specific promoters operably linked to target sequences (TS). Recombinase inversion or excision yields double-stranded TS RNA, which thereby functions to trigger endogenous gene silencing mechanisms. By matching promoters, responsive to various inducers, plant tissues or plant developmental states with the recombinase systems, transcriptional stop fragments or introns and target sequences, gene silencing of virtually any target sequence may be modulated at any plant development stage or in any plant generation. This is especially useful, when genes responsible for gene silencing are down-regulated to permit expression of particular transgenes at levels greater than permitted when gene silencing is activated.
摘要:
A nucleic acid fragment encoding a herbicide-resistant plant acetolactate synthase protein is disclosed. This nucleic acid fragment contains at least one nucleotide mutation resulting in one amino acid change in one of seven substantially conserved regions of acetolactate synthase amino acid homology. This mutation results in the production of an acetolactate synthase protein which is resistant to sulfonylurea herbicide compounds compared to the wild-type protein. Transformation of herbicide sensitive plants or plant cells with the fragment results in resistance to the herbicide.