Identification of Δ12 fatty acid desaturase gene by somatic knockout in Tetrahymena thermophila.

MARIA LUZ SANCHEZ; CID NICOLAS; NUSBLAT AD; CLARA B. NUDEL

Mar del Plata

Congreso; LI Reunion Anual 2015; 2015

Sociedad Argentina de Investigacion Bioquimica y Biologia Molecular

Polyunsaturated fatty acids (PUFAs) play important roles as structural components ofmembrane phospholipids and as precursors of eicosanoids. Mammals synthesize eicosanoids, which are involved in inflammatory and immune responses, reproduction, and blood pressure regulation. However, they are unable to add double bonds at Δ12 or Δ15 positions; for this reason PUFAs linoleate (18:2Δ9,12) and linolenate (18:3Δ9,12,15) must be obtained from the diet.The study of PUFAs metabolism in microorganisms can contribute to develop better biotechnological strategies for their production. In this regard, the ciliated Tetrahymena thermophila seems to be a good model for this purpose.We have undertaken a genome-wide survey of putative genes involved in PUFA metabolism in T. thermophila. A number of candidates were selected as possible fatty acid desaturases (FADs). Gene deletion by somatic knockout of the only Δ12 FAD ortholog present in T. thermophila (TTHERM_00535680) unables to synthesize a double bond at position 12 of lipid´s fatty acid (FA) chain. Gas chromatography-Mass spectrometry analysis of purified FAs showed that the main PUFA (18:3Δ6,9,12) present in the wild type couldn´t be detected in the mutant strain.Further studies of FADs metabolism in ciliates could contribute to the understanding of lipid biosynthesis pathways and to generate recombinant strains with biotechnological value.