Association of an ACSL1 gene variant with polyunsaturated fatty acids in bovine skeletal muscle

Abstract

BackgroundThe intramuscular fat deposition and the fatty acid profiles of beef affect meat quality. High proportions of unsaturated fatty acids are related to beef flavor and are beneficial for the nutritional value of meat. Moreover, a variety of clinical and epidemiologic studies showed that particularly long-chain omega-3 fatty acids from animal sources have a positive impact on human health and disease.ResultsTo screen for genetic factors affecting fatty acid profiles in beef, we initially performed a microsatellite-based genome scan in a F2 Charolais × German Holstein resource population and identified a quantitative trait locus (QTL) for fatty acid composition in a region on bovine chromosome 27 where previously QTL affecting marbling score had been detected in beef cattle populations. The long-chain acyl-CoA synthetase 1 (ACSL1) gene was identified as the most plausible functional and positional candidate gene in the QTL interval due to its direct impact on fatty acid metabolism and its position in the QTL interval. ACSL1 is necessary for synthesis of long-chain acyl-CoA esters, fatty acid degradation and phospholipid remodeling. We validated the genomic annotation of the bovine ACSL1 gene by in silico comparative sequence analysis and experimental verification. Re-sequencing of the complete coding, exon-flanking intronic sequences, 3' untranslated region (3'UTR) and partial promoter region of the ACSL1 gene revealed three synonymous mutations in exons 6, 7, and 20, six noncoding intronic gene variants, six polymorphisms in the promoter region, and four variants in the 3' UTR region. The association analysis identified the gene variant in intron 5 of the ACSL1 gene (c.481-233A>G) to be significantly associated with the relative content of distinct fractions and ratios of fatty acids (e.g., n-3 fatty acids, polyunsaturated, n-3 long-chain polyunsaturated fatty acids, trans vaccenic acid) in skeletal muscle. A tentative association of the ACSL1 gene variant with intramuscular fat content indicated that an indirect effect on fatty acid composition via modulation of total fat content of skeletal muscle cannot be excluded.ConclusionsThe initial QTL analysis suggested the ACSL1 gene as a positional and functional candidate gene for fatty acid composition in bovine skeletal muscle. The findings of subsequent association analyses indicate that ACSL1 or a separate gene in close proximity might play a functional role in mediating the lipid composition of beef.

0309 Systematic profiling of short tandem repeats in the cattle genome

“…PRKG1 was identified as one of 20 genes associated with milk fatty acid traits in Holstein (Li et al 2014), and its functions include calcium channel regulator activity and cGMP-dependent protein kinase activity. This study also identified ACSL1 associated with the milk fatty acid traits (Li et al 2014) and supported by other studies (Widmann et al 2011;Gao et al 2013;Weber et al 2013). Other identified genes in our current study are involved in somatic cell score and meat quality traits, such as GRIN2B (Wu et al 2014) and PLXNA4 (Strillacci et al 2014).…”

Consumer Acceptability of Intramuscular Fat

“…The data strongly suggested that differences in the flavor of grass and grain fed beef is mainly due to differences in fat level rather than due to inherent grass or grain flavors (Frank et al , 2016). Refinement of animal production and feeding strategies to optimize the composition of IMF and enhance sensory properties of beef will present new opportunities for producers of marbled beef (Barendse, 2014; Scollan et al , 2014; Widmann et al , 2011). …”

“…Many Asian consumers prefer moderate amounts of IMF in the meat they purchase, whereas visible fat is unpopular with Western (e.g., Europe, Australia) consumers. The amount of IMF within beef muscle varies widely depending on animal breed or genetics (Barendse, 2014; Hocquette et al , 2014; Widmann et al , 2011), the nutrition system (pasture or grain) (Duckett et al , 2013; Sithyphone et al , 2011; Van Elswyk and McNeill, 2014), animal maturity and weight (Duckett et al , 2014; Frank et al , 2016), primal (Pavan and Duckett, 2013) and other factors. Marbling describes the small flecks of visible fat deposited between individual muscle fiber bundles.…”

Genetic polymorphisms of the FATP1 gene and their associations with meat quality traits in Chinese Qinchuan cattle

“…The g.28381 G>A was in intron 3, and g.28265 G>C, g.28470 T>C, and g.28672 G>A were silent mutations found in exons 3, 4, and 5, respectively. Since IMF deposition and the fatty acid profiles of beef affect meat quality (Widmann et al, 2011), and the gene expression abundance of FATP1 has been shown to exhibit significant positive correlations (P < 0.05) with IMF content in LM , it was hypothesized that this mutation may influence FATP1 protein synthesis. However, this needs to be validated in future studies.…”