LAUSR

The use of stable isotope tracers and mass spectrometry (MS) is the gold standard method for the analysis of fatty acids (FAs) metabolism. Yet current state-of-the-art tools provide limited and difficult to interpret information about FA biosynthetic routes. Here we present FAMetA, an R-package and a web-based application (www.fameta.es) that use 13C mass-isotopologue profiles to estimate FA import, de novo lipogenesis, elongation, and desaturation in a user-friendly platform. The FAMetA workflow covers all the functionalities needed for MS data analyses. To illustrate its utility, different in vitro and in vivo experimental settings are used in which FA metabolism is modified. Thanks to the comprehensive characterisation of FA biosynthesis and the easy-to-interpret graphical representations compared to previous tools, FAMetA discloses unnoticed insights into how cells reprogramme their FA metabolism and, when combined with FASN, SCD1 and FADS2 inhibitors, it enables the straightforward identification of new FAs by the metabolic reconstruction of their synthesis route.