Seasonal and Sexual Variation in mRNA Expression of Selected Adipokine Genes Affecting Fat Deposition and Metabolism of the Emu (Dromaius Novaehollandiae)

Abstract

Emus are farmed for fat production. Oil rendered from their back and abdominal fat pads has good anti-oxidant and anti-inflammatory properties and has ingredients that promote cell growth. Our objective is to examine the mRNA expression of 7 emu adipokine genes (eFABP4, eSCD1, eAdipoQ, eAdipoR1, eAdipoR2, Lept and eLepR) to identify gene markers that may help improve emu fat production. Back and abdominal fat tissues from 11 adult emus were biopsied at four time points (April, June, August and November). Total RNA was isolated and cDNA was synthesized. Gene specific primers were designed for partial cloning fragments to amplify the open reading frame of the 7 genes. Lept was not expressed in emu fat tissue. Nucleotides and amino acids sequences of the 6 expressed gene were compared with homologs from other species and phylogenetic relationships established. Seasonal mRNA expression of each gene was assessed by quantitative RT-PCR and differential expression analysed by the 2−ΔΔCT method. The temporal mRNA expression pattern of the genes and the fat gain (kg) between time points association with gene expression level were determined. More whole-genome scanning studies are needed to develop novel molecular markers that can be applied to improve fat production in emus.