Fatty acids composition ofCaenorhabditis elegansusing accurate mass GCMS-QTOF

Abstract

The free living nematode Caenorhabditis elegans is a proven model organism for lipid metabolism research. Total lipids of C. elegans were extracted using chloroform, methanol 2:1(v/v). Fatty acids composition of the extracted total lipids were converted to their corresponding methyl esters (FAMEs) and analyzed by gas chromatography/accurate mass quadrupole time of flight mass spectrometry (GCMS-QTOF) using both electron ionization (EI) and chemical ionization (CI) techniques. 28 fatty acids consisting of 12 to 22 carbon atoms were identified, 65% of them were unsaturated. Fatty acids containing 12 to 17 carbons were mostly saturated with stearic acid (18:0) as the major constituent. Several branched-chain fatty acids were identified. Methyl-14-methylhexadecanoate (iso-17:0) was the major identified branched fatty acid. This is the first report to detect the intact molecular parent ions of the identified fatty acids using chemical ionization compared to electron ionization which produced fragmentations of the fatty acids methyl esters (FAMEs).

Metabolomes and Lipidomes of the Infective Stages of the Gastrointestinal nematodes, Nippostrongylus brasiliensis and Trichuris muris

“…Thus, we presume that fatty acids, such as octadecanoic acid detected in the ESP of N. brasiliensis L3, might be playing a key role during the process of host invasion and infection. Fatty acids were also reported in other nematodes such as Haemonchus contortus (in all stages of life-cycle) [119] and adult Caenorhabditis elegans [120], and in both studies, fatty acids with 18 carbons (i.e., 18:1, 18:2, and 18:3) were commonest. We also obtained a similar result, where~7% of total lipids were fatty acids, and the above-mentioned fatty acids with 18 carbons were present in all three samples (i.e., NB_SE, NB_ESP, and TM_SE).…”

A Marine Actinomycete Rescues Caenorhabditis elegans from Pseudomonas aeruginosa Infection through Restitution of Lysozyme 7

“…(González et al, 2005 ; Ser et al, 2016 ). Methyl ester of tridecanoic acid, tetradecanoic acid, hexadecanoic acid, pentadecanoic acid 14-methyl, and tetradecanoic acid 12-methyl have also been reported in C. elegans (Henry et al, 2016 ). Although the actual mechanism by roles these compounds protect C. elegans from PA14-induced mortality is still unclear, some hints as to their possible functions could be derived from literature pertaining to C. elegans immunity and fatty acids.…”

Quo Vadis Caenorhabditis elegans Metabolomics—A Review of Current Methods and Applications to Explore Metabolism in the Nematode

“…Identification of lipids is thereby accomplished on their accurate mass and/or MS/MS characterization. GC-MS has been used for metabolomics in C. elegans to identify fatty acids, amino acids, or organic acids [ 31 , 42 , 43 , 50 , 59 , 65 , 72 , 73 , 74 , 75 ]. Not only coupled to MS, but also GC using a flame ionization detector (FID) has been used as a complementary analytical platform in C. elegans to determine the fatty acid composition [ 42 , 43 , 45 ].…”

“…Figure 2 illustrates the percentage of certain FAs that have been determined in several publications. One of the more recent investigations was performed by Henry et al, which determined fatty acid composition of WT worms using EI and CI at GC-QToF-MS. 28 fatty acids have been identified using their accurate mass and isotopic ratio, obtained at CI, and accurate mass fragmentation pattern provided by EI [75]. Although the actual fatty acid content is very dependent on the actual bacterial diet [127], several key features are conserved from different analyses.…”

“…The genetic basis for the biosynthesis of fatty acids have been unraveled by Watts and Browse using GC-FID [ 124 ]. The fatty acid composition of C. elegans and individual lipid classes has been determined multiple times [ 42 , 75 , 85 , 90 , 93 , 125 , 126 , 127 , 128 ]. A comprehensive overview of the C. elegans lipidome can be found in the review by Witting et al [ 123 ].…”