Short communication Polymorphism of the porcine miR-30d is associated with adipose tissue accumulation, its fatty acid profile and the ME1 gene expression M. Bartz a , E. Koscianska b , I. Szczerbal a , J. Nowacka-Woszuk a , B. Kociucka a , S. Salamon a , M. Switonski a , M. Szydlowski a,n a Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Poland b Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poland article info Article history: Received 9 July 2015 Received in revised form 21 October 2015 Accepted 23 October 2015 Keywords: Pig Fatness Adipogenesis Fatty acids Body mass gain MiR-30 Malic enzyme abstract The miR-30 gene family includes potential regulators of adipogenesis. We searched for polymorphism in this gene family in 4 pig breeds: Duroc, Pietrain, Polish Landrace (PL), Polish Large White (PLW) and a synthetic line (L990). Altogether 5 single nucleotide polymorphisms (SNPs) in 3 genes were found, including one already known SNP rs340704946 within the pre-miR-30d genomic sequence. An association of the rs340704946 with intramuscular fat (IMF) content, abdominal fat accumulation and daily body mass gain in L990 was found. Moreover, the AG genotype was associated with an increased content of monounsaturated fatty acids (MUFA) in subcutaneous (P ¼0.027) and visceral fat (P ¼0.007) tissues when compared to the GG genotype. Analysis of PLW pigs revealed an association of the rs340704946 with transcript level of the ME1 gene in longissimus dorsi (LD) muscle (P ¼0.002), as well as the ME1 protein product in the LD muscle (P o0.001) and subcutaneous fat (P o0.001). We conclude that the rs340704946 can be considered as a functional polymorphism for pig production traits and fatty acid profile in adipose tissue. & 2015 Elsevier B.V. All rights reserved. 1. Introduction The miR-30 gene family includes potent regulators of human adipogenesis (Peng et al., 2014). Up-regulation of the miR-30 genes promotes adipogenesis of adipose tissue-derived stem cells, whereas inhibition of its expression blocks this process (Zaragosi et al., 2011). It was also observed that miR-30d gene is down- regulated in obese patients (Perri et al., 2012). According to the miRBase and pigQTLdb databases, the pig miR- 30 family genes are located in three autosomes: SSC1 (miR-30a, miR-30c2), SSC4 (miR-30b, miR-30d) and SSC6 (miR-30c1, miR- 30e), within the QTL regions for longissimus dorsi (LD) muscle area, backfat thickness, average daily gain and intramuscular fat (IMF) content (Kozomara and Griffiths-Jones, 2014; Zhi-Liang et al., 2013). In silico study suggests that the miR-30 family downregulates the ME1 gene. The ME1 gene encoding the malic enzyme is expressed in the adipose tissue and involved in fatty acid metabolism (Ramírez et al., 2014). Deep sequencing demonstrated co-expression of the miR-30 and ME1 genes in porcine adipose and muscle tissues (Nielsen et al., 2010; Li et al., 2012). It was also reported that a polymorphism within the 3’ UTR of the ME1 gene may alter ME1 transcript level (Bartz et al., 2014). We hypothesized that a regulatory mechanism of porcine fat- ness involves miR-30 gene family and polymorphism within the genes may influence fatness via its effect on the ME1 gene ex- pression. Thus, the aim of the present study was searching for polymorphism in the porcine miR-30 gene family and its asso- ciation with production traits, fatty acid (FA) profile in fat depots and the ME1 expression. 2. Materials and methods 2.1. Animals and phenotypes Three sample sets of gilts were included in this study (Table 1). All gilts were reared under the same conditions at a local Pig Testing Station, fed individually ad libitum with a commercial feed mix and slaughtered at 100 kg of body weight. The carcasses were dissected and the following traits were measured: backfat thickness (mm), abdominal fat weight (kg), lean meat content (%) and IMF content (%). Backfat thickness was measured with a ruler at 7 points: over the shoulder, over the back, at sacrum points I–III and at points C1 and K1 (on the vertical line extending from the height and a side edge of the LD muscle, respectively). These measurements were treated separately as 7 different phenotypic traits. IMF content was measured using the SOXTEC AVANTI 2050 automatic extraction Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/livsci Livestock Science http://dx.doi.org/10.1016/j.livsci.2015.10.019 1871-1413/& 2015 Elsevier B.V. All rights reserved. n Correspondence Address: Wolynska 33, 60-637 Poznan, Poland. Fax: þ48 61 8487148. E-mail address: maciej@up.poznan.pl (M. Szydlowski). Livestock Science 182 (2015) 54–57