Transcript abundance of the pig stearoyl-CoA desaturase gene has no effect on fatty acid composition in muscle and fat tissues, but its polymorphism within the putative microRNA target site is associated with daily body weight gain and feed conversion ratio1

Abstract

Fatty acid composition in porcine intramuscular fat affects the dietetic value and technological properties of meat. The stearoyl-CoA desaturase (SCD) gene is a strong positional and functional candidate for fatty acid composition. Our sequence analysis in 4 breeds (Duroc, Pietrain, Polish Landrace, and Polish Large White) revealed a novel SNP in the 5'-flanking sequence and 9 novel SNP and 2 novel indels in the 3' untranslated region (UTR). Transcript level of the SCD in subcutaneous fat was significantly greater than in muscle tissue (n=83; P<0.001) and the interbreed comparison revealed a greater transcript level in the fat tissue of Polish Landrace (P<0.01). We found no association between the abundance of the SCD transcript and fatty acid composition in any of the tissues. We performed an association analysis between 4 SNP (c.-353C>T, c.-233T>C, c.*164A>G, and c.*928G>C), 1 indel (c.*2574_2576delGTC), and production traits in Polish Large White (n=185) and synthetic line 990 (n=243). The most pronounced associations were observed for the c.*928G>C polymorphism, which occurs within a predicted target site for 2 microRNA (ssc-miR-185 and ssc-miR-491). In line 990, this polymorphism was significantly associated with daily BW gain (P<0.04 under the general model) and feed conversion ratio (P<0.0004) but not with fatness traits. The same tendency, but not significant, was observed in the Polish Large White breed. When both breeds were analyzed together, these associations were again highly significant (daily BW gain P<0.003; feed conversion ratio P<0.0001). We conclude that c.*928G>C is a promising marker for both porcine traits.

Novel single nucleotide polymorphisms in the 5' regulatory region of the duck SCD1 gene and their associations with serum biochemical levels and fatty acid composition

“…Similar research has been reported in pigs, where the C/T mutation at position 3101 was detected in exon 2 of the porcine SCD1 gene and found to be significantly associated with carcass weight (Renaville et al, 2015). The observed effect on carcass weight may result from an effect of SCD on the feed conversion ratio and daily body weight gain, as reported by Bartz et al (2013), and/ or on growth as reported by Chen et al (2011) in goats. In Chinese goat breeds, three SNPs (IVS3+55A > G in intron 3, and EX3_15G > A and EX3_68A > G in exon 3) were discovered by DNA pooling and PCR-restriction fragment length polymorphism, and the EX3_15G > A missense mutation resulted in an amino acid substitution from Val to Met in the 109 amino acid position of the SCD protein (359 amino acids).…”

Stearoyl-CoA Desaturase Genes in Lipid Metabolism

“…Similar associations of SCD polymorphisms with fatty acid composition have been reported for pigs (Bartz et al 2013 ;Uemoto et al 2012 ;Wang et al 2013 ). Two groups (Bartz et al 2013 ;Uemoto et al 2012 ) have identifi ed SNPs in the SCD promoter region in pigs that were associated with fatty acid composition, and Uemoto et al ( 2012 ) identifi ed QTL for 14:0, 18:0, and 18:1 n -9 located near the porcine SCD gene.…”

A Functional Variant in the Stearoyl-CoA Desaturase Gene Promoter Enhances Fatty Acid Desaturation in Pork

“…However, considering the results from a Landrace × Korean native pig intercross in which these two SNPs segregated independently [22], we can conclude that fatty acid composition was associated to an haplotype comprised, in its 5′ extreme, not beyond the g.2109 position and, in its 3′ end, not past the g.2280 nucleotide ( Figure 2 ). However, no other mutations have been described in this short 173 bp region in other studies which have extensively sequenced the SCD promoter in independent Duroc lines [21]–[24], including the present study. In contrast, the g.2228T>C SNP is common to all the studies which have found a significant relationship between the SCD promoter genotype and fatty acid composition [21], [22].…”

“…Taken together, these findings strongly support that allele T at g.2228T>C is the causative mutation leading to increased fatty acid desaturation. Interestingly, this allele is virtually absent in the Asian breeds [30] and, in contrast, almost fixed in other breeds, including Landrace, Pietrain, Iberian, and wild boar ( Table 1 ; [24]). This explains why whole-genome analyses based on these latter breeds failed to identify SCD as a positional candidate gene for fatty acid composition.…”

“…Several single nucleotide polymorphisms (SNP) in the SCD promoter region have been associated to 18∶0 and 18∶1 content. Yet, results are inconclusive, as either the location of haplotypes is not coincident [21], [22], favorable alleles are swapped [23], or even no association was found [24]. We have been collecting since 2002 samples of subcutaneous fat, muscle, and liver from a full-pedigreed Duroc line [25] and muscle samples from three ad hoc pig crossbreds divergent for fatness.…”