Elongation of very long chain fatty acids in the African Catfish Clarias gariepinus: cloning, functional chracterisation and tissue distribution of ELOVL4 Elongases

Elongation of very-long chain fatty acid (Elovl) proteins are enzymes that catalyse the condensation reaction, the first and rate-limiting step out of four sequential reactions required for the elongation of fatty acids (FAs) (Jakobsson et al., 2006). Seven members (Elovl1-7) make up the elongase protein family in vertebrates, with Elovl4 having a major role in the biosynthesis of very long-chain (≥ C24) FAs of both saturated and polyunsaturated (VLC-PUFA) acyl chains (Agbaga et al., 2008). Recent studies have shown that fish possess two different forms of Elovl4, namely Elovl4a and Elovl4b, with different functions and spatial-temporal expression patterns during development (Monroig et al., 2010). We have recently initiated the investigation of Elovl and fatty acyl desaturase (Fads) genes that participate in the biosynthesis of essential FAs in Clarias gariepinus, a commercially important fish species in Africa (Oboh et al., 2016). In this study, we aimed to characterise both molecularly and functionally two elovl4 cDNAs from C. gariepinus, and investigate their tissue distribution