Desaturases of a green microalga and uses thereof

Abstract

Isolated proteins which are at least partially encoded by polynucleotide sequences encoding novel desaturases are provided together with a composition which includes these isolated proteins. A transgenic plant, a transgenic alga, or a transgenic seed transformed by the polynucleotides encoding proteins which are at least partially encoded by novel desaturases are also provided. The invention also includes a process for making a very long-chain polyunsaturated fatty acid in a transformed cell, a transgenic alga, or a transgenic plant expressing the isolated protein or proteins which are at least partially encoded by the polynucleotide sequences encoding novel Δ5, Δ6, or Δ12 desaturases.

1 . An isolated protein comprising, an amino acid sequence set forth in SEQ ED NO: 1. 
     
     
         2 . A composition comprising the protein of  claim 1 . 
     
     
         3 . An isolated protein comprising, an amino acid sequence set forth in SEQ ID NO: 2. 
     
     
         4 . A composition comprising the protein of  claim 3 . 
     
     
         5 . An isolated protein comprising, an amino acid sequence set forth in SEQ ID NO: 3. 
     
     
         6 . A composition comprising the protein of  claim 5 . 
     
     
         7 . An isolated polynucleotide comprising a coding portion encoding the protein of  claim 1 . 
     
     
         8 . The isolated polynucleotide of  claim 7 , wherein said coding portion comprises a nucleic acid sequence set forth in SEQ ID NO: 4. 
     
     
         9 . An isolated polynucleotide comprising a coding portion encoding the protein of  claim 3 . 
     
     
         10 . The isolated polynucleotide of  claim 9 , wherein said coding portion comprises a nucleic acid sequence set forth in SEQ ID NO: 5. 
     
     
         11 . An isolated polynucleotide comprising a coding portion encoding the protein of  claim 5 . 
     
     
         12 . The isolated polynucleotide of  claim 11 , wherein said coding portion comprises a nucleic acid sequence set forth in SEQ ID NO: 6. 
     
     
         13 . An expression vector comprising the polynucleotide of  claim 7 . 
     
     
         14 . An expression vector comprising the polynucleotide of  claim 9 . 
     
     
         15 . An expression vector comprising the polynucleotide of  claim 11 . 
     
     
         16 . A cell comprising the expression vector of  claim 13 . 
     
     
         17 . A cell comprising the expression vector of  claim 14 . 
     
     
         18 . A cell comprising the expression vector of  claim 15 . 
     
     
         19 . A transgenic plant, a transgenic seed, or a transgenic alga transformed by a polynucleotide of  claim 7 . 
     
     
         20 . A transgenic plant, a transgenic seed, or a transgenic alga transformed by a polynucleotide of  claim 9 . 
     
     
         21 . A transgenic plant, a transgenic seed, or a transgenic alga transformed by a polynucleotide of  claim 11 . 
     
     
         22 . A transgenic seed, produced by a transgenic plant transformed by a polynucleotide of  claim 7 . 
     
     
         23 . A transgenic seed, produced by a transgenic plant transformed by a polynucleotide of  claim 9 . 
     
     
         24 . A transgenic seed, produced by a transgenic plant transformed by a polynucleotide of  claim 11 . 
     
     
         25 . A method of producing very long-chain polyunsaturated fatty acid (VLC-PUFA) in a plant, a plant cell, or an alga comprising the step of transforming a plant, a plant cell, or an alga with a polynucleotide of  claim 7 , thereby producing a VLC-PUFA in a plant, a plant cell, or an alga. 
     
     
         26 . A method of producing very long-chain polyunsaturated fatty acid (VLC-PUFA) in a plant, a plant cell, or an alga, comprising the step of transforming a plant, a plant cell, or an alga with a polynucleotide of  claim 9 , thereby producing a VLC-PUFA in a plant, a plant cell, or an alga. 
     
     
         27 . A method of producing very long-chain polyunsaturated fatty acid (VLC-PUFA) in a plant, a plant cell, or an alga, comprising the step of transforming a plant, a plant cell, or an alga with a polynucleotide of  claim 11 , thereby producing a VLC-PUFA in a plant, a plant cell, or an alga. 
     
     
         28 . The method of  claim 25 , wherein said plant, said plant cell, or said alga comprises linoleic acid (LA; 18:2ω6), α-linolenic acid (ALA; 18:3ω3), oleic acid (18:1), dihomo-gamma-linolenic acid (20:3ω6), phosphatidylcholine (PC), diacylglyceroltrimethylhomoserine (DGTS), phosphatidylethanolamine (PE), or any combination thereof. 
     
     
         29 . The method of  claim 25 , wherein said VLC-PUFA is eicosapentaenoic acid (EPA, 20:5ω3), docosahexaenoic acid (DHA, 22:6ω3), dihomo-gamma-linolenic acid (DGLA), or arachidonic acid (ARA, 20:4ω6) 
     
     
         30 . The method of  claim 25 , wherein said plant, said plant cell, or said alga is grown under oleogenic conditions, under nitrogen starvation conditions, or a combination thereof. 
     
     
         31 . The method of  claim 25 , wherein said producing very long-chain polyunsaturated fatty acid (VLC-PUFA) is enhancing oil storage, arachidonic acid accumulation, eicosapentaenoic acid accumulation, docosahexaenoic acid accumulation, dihomo-gamma-linolenic acid accumulation, or a combination thereof. 
     
     
         32 . The method of  claim 25 , further comprising the a step of transforming said plant, said plant cell, or said alga with a polynucleotide of  claim 9 , a polynucleotide of  claim 11 , a polynucleotide encoding a PUFA-specific elongase, or any combination thereof. 
     
     
         33 . The method of  claim 26 , further comprising the a step of transforming said plant, said plant cell, or said alga with a polynucleotide of  claim 7 , a polynucleotide of  claim 11  , a polynucleotide encoding a PUFA-specific elongase, or any combination thereof. 
     
     
         34 . The method of  claim 27 , further comprising the a step of transforming said plant, said plant cell, or said alga with a polynucleotide of  claim 7 , a polynucleotide of  claim 9 , a polynucleotide encoding a PUFA-specific elongase, or any combination thereof. 
     
     
         35 . The method of  claim 26 , wherein said plant, said plant cell, or said alga comprises linoleic acid (LA; 18:2ω6), α-linolenic acid (ALA; 18:3ω3), oleic acid (18:1), dihomo-gamma-linolenic acid (20:3ω6), phosphatidylcholine (PC), diacylglyceroltrimethylhomoserine (DGTS), phosphatidylethanolamine (PE), or any combination thereof. 
     
     
         36 . The method of  claim 26 , wherein said VLC-PUFA is eicosapentaenoic acid (EPA, 20:5ω3), docosahexaenoic acid (DHA, 22:6ω3), dihomo-gamma-linolenic acid (DGLA), or arachidonic acid (ARA, 20:4ω6) 
     
     
         37 . The method of  claim 26 , wherein said plant, said plant cell, or said alga is grown under oleogenic conditions, under nitrogen starvation conditions, or a combination thereof. 
     
     
         38 . The method of  claim 26 , wherein said producing very long-chain polyunsaturated fatty acid (VLC-PUFA) is enhancing oil storage, arachidonic acid accumulation, eicosapentaenoic acid accumulation, docosahexaenoic acid accumulation, dihomo-gamma-linolenic acid accumulation, or a combination thereof. 
     
     
         39 . The method of  claim 27 , wherein said plant, said plant cell, or said alga comprises linoleic acid (LA; 18:2ω6), a-linolenic acid (ALA; 18:3ω3), oleic acid (18:1), dihomo-gamma-linolenic acid (20:3ω6), phosphatidylcholine (PC), diacylglyceroltrimethylhomoserine (DGTS), phosphatidylethanolamine (PE), or any combination thereof. 
     
     
         40 . The method of  claim 27 , wherein said VLC-PUFA is eicosapentaenoic acid (EPA, 20:5ω3), docosahexaenoic acid (DHA, 22:6ω3), dihomo-gamma-linolenic acid (DGLA), or arachidonic acid (ARA, 20:4ω6) 
     
     
         41 . The method of  claim 27 , wherein said plant, said plant cell, or said alga is grown under oleogenic conditions, under nitrogen starvation conditions, or a combination thereof. 
     
     
         42 . The method of  claim 27 , wherein said producing very long-chain polyunsaturated fatty acid (VLC-PUFA) is enhancing oil storage, arachidonic acid accumulation, eicosapentaenoic acid accumulation, docosahexaenoic acid accumulation, dihomo-gamma-linolenic acid accumulation, or a combination thereof.