Molecular genetics-nutrition interactions in the expression of AANAT, ADRB3, BTG2 and FASN genes in the heart, kidney and liver of Australian lambs supplemented with Spirulina (Arthrospira platensis)

Quantitative reverse transcriptase polymerase chain reaction was used to assess the messenger RNA (mRNA) transcription levels and expressions of Aralkylamine N-acetyltransferase, Adrenergic beta-3 receptor, B cell translocation gene 2, and Fatty acid synthase genes. In total, 432 heart, kidney and liver samples from 48 purebred and crossbred Australian prime lambs supplemented with Spirulina (Arthrospira platensis) blue-green cyanobacterial microalgae over a 9-week feeding trial were utilized for fatty acid composition and mRNA extraction. The aim was to assess the effect of dietary Spirulina supplementation on the mRNA expression profiles of genes controlling fatty acid metabolism in the heart, kidney and liver. Fourty-eight weaned lambs belonging to four breeds under the same management conditions were maintained on ryegrass pasture and randomly allocated to three treatment groups that comprised the control and two levels of Spirulina supplementation: Low (100mL/head/day of 1 g Spirulina powder dissolved in 10 mL of water (10% wt:vol)) and High (200 mL/head/day of 2 g of Spirulina dissolved in 10 mL of water (20% wt:vol)). Both the low and high levels of Spirulina supplementation regimes strongly up-regulated the transcription of all the selected genes and increased w-3 and w-6 polyunsaturated fatty acid compositions in the tested organs. Breed and sex did not influence gene expression patterns; however, significant variations in response to Spirulina supplementation underpin the genetics-nutrition interactions that could be of practical importance for manipulating meat quality in the Australian dual-purpose prime lamb industry for a healthy polyunsaturated fatty acid profile.