title: Alternative splicing generates novel Fads3 transcript in mice.
abstract: Fads3 is the third member of the fatty acid desaturase gene cluster; with at least eight evolutionarily conserved alternative transcripts (AT), having no clearly established function as are known for FADS2 and FADS1. Here we present identification of a novel Fads3 transcript in mice (Fads3AT9), characterize Fads3AT9 expression in mouse tissues and evaluate correlations with metabolite profiles. Total RNA obtained from mouse tissues is reverse-transcribed into cDNA and used as template for PCR reactions. Tissue fatty acids were extracted and quantified by gas chromatography. Sequencing analysis revealed complete absence of exon 2 resulting in an open reading frame of 1239 bp, encoding a putative protein of 412 aa with loss of 37 aa compared to classical Fads3 (Fads3CS). FADS3AT9 retains all the conserved regions characteristic of front end desaturase (cytochrome b5 domain and three histidine repeats). Both Fads3CS and Fads3AT9 are ubiquitously expressed in 11 mouse tissues. Fads3AT9 abundance was greater than Fads3CS in pancreas, liver, spleen, brown adipose tissue and thymus. Fads3CS expression is low in pancreas while Fads3AT9 is over ten-fold greater abundance. The eicosanoid precursor fatty acid 20:4n - 6, the immediate desaturation product of the Fads1 coded Δ5-desaturase, was highest in pancreas where Fads3CS is low. Changes in expression patterns and fatty acid profiles suggest that Fads3AT9 may play a role in the regulation and/or biosynthesis of long chain polyunsaturated fatty acids from precursors.
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Ji Yao
authors.initials: JY
authors.lastname: Zhang
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.|College of Veterinary Medicine, Jilin University, Changchun, Jilin, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Qin
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Hui Gyu
authors.initials: HG
authors.lastname: Park
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Ellen
authors.initials: E
authors.lastname: Kim
authors.affiliation: College of Veterinary Medicine, Jilin University, Changchun, Jilin, China.
authors.forename: Guowen
authors.initials: G
authors.lastname: Liu
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Kumar S D
authors.initials: KSD
authors.lastname: Kothapalli
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
authors.forename: J Thomas
authors.initials: JT
authors.lastname: Brenna
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D044943:Fatty Acid Desaturases / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008297:Male; D008810:Mice, Inbred C57BL; D009928:Organ Specificity; D010179:Pancreas / Q000201:enzymology; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism
chemical_list: C000614171:Fads3 protein, mouse; D007527:Isoenzymes; D012333:RNA, Messenger; D044943:Fatty Acid Desaturases
keywords: Alternative splicing; Alternative transcript; Fatty acid desaturase; Long chain polyunsaturated fatty acids