Alternative splicing generates a novel FADS2 alternative transcript in baboons

The mammalian fatty acid desaturase 2 (FADS2) gene codes for catalytic activity considered to be the rate limited step in long chain polyunsaturated fatty acid (LCPUFA) synthesis. FADS2 catalyzes 6-desaturation in at least five substrates and 8-desaturation in at least two substrates. However, the molecular mechanisms that regulate FADS2-mediated desaturation remain ill-defined. We report here characterization of an alternative transcript (AT1) of primate FADS2 and compare its expression to that of the classical transcript in 12 tissues of a 12 week old neonate baboon, and in human SK-N-SH neuroblastoma (NB) cells. RT-PCR analysis indicates relatively greater abundance of classical transcript than AT1 in all tissues. However, AT1 expression is highly variable, showing greater expression in liver, retina, occipital lobe, hippocampus, spleen, and ovary, than in other tissues, whereas classical transcript displayed little variability. These data suggest that FADS2 AT1 is a candidate for regulation of LCPUFA synthesis.