Imprinting analysis of porcine <Emphasis Type="Italic">DIO3</Emphasis> gene in two fetal stages and association analysis with carcass and meat quality traits

Imprinted genes play important roles in mammalian growth, development and behavior. In this study, we obtained 1568 bp mRNA sequence of porcine DIO3 (deiodinase, iodothyronine, type III), and also identified its imprinting status during porcine fetal development. The complete open reading frame (ORF) encoding 278 amino acids. The porcine DIO3 mRNA was expressed predominantly in backfat, mildly in liver, uterus, kidney, heart, small intestine, muscle and stomach, and almost absent in spleen and lung. A single nucleotide polymorphism in exon (A/C ⁶⁸⁷) was used to investigate the allele frequencies in different pig breeds and the imprinting status in porcine embryonic tissues. The results indicate that DIO3 was imprinted in all the tested tissues. Statistical analysis showed the DIO3 gene polymorphism was significantly associated with almost all the fat deposition and carcass traits, including lean meat percentage (LMP), fat meat percentage (FMP), ratio of lean to fat (RLF), shoulder fat thickness (SFT), sixth–seventh rib fat thickness (RFT), buttock fat thickness (BFT), loin eye area (LEA), and intramuscular fat (IMF).     

Identification of three novel SNPs and association with carcass traits in porcine <Emphasis Type="Italic">TNNI1</Emphasis> and <Emphasis Type="Italic">TNNI2</Emphasis>

In this study, two novel SNPs (EU743939:g.5174T>C in intron 4 and EU743939:g.8350C>A in intron 7) in TNNI1 and one SNP (EU696779:g.1167C>T in intron 3) in TNNI2 were identified by PCR–RFLP (PCR restriction fragment length polymorphism) using XbaI, MspI and SmaI restriction enzyme, respectively. The allele frequencies of three novel SNPs were determined in the genetically diverse pig breeds including ten Chinese indigenous pigs and three Western commercial pig breeds. Association analysis of the SNPs with the carcass traits were conducted in a Large White × Meishan F₂ pig population. The linkage of two SNPs (g.5174T>C and g.8350C>A) in TNNI1 gene had significant effect on fat percentage. Besides these, the g.5174T>C polymorphism was also significantly associated with skin percentage (P < 0.05), shoulder fat thickness (P < 0.05) and backfat thickness between sixth and seventh ribs (P < 0.05). The significant effects of g.1167C>T polymorphism in TNNI2 gene on fat percentage (P < 0.01), lean meat percentage (P < 0.05), lion eye area (P < 0.05), thorax–waist backfat thickness (P < 0.01) and average backfat thickness (P < 0.05) were also found.     

Genome-wide association study for growth and fatness traits in Chinese Sujiang pigs

Growth and fatness traits are complex and economically important traits in the pig industry. The molecular basis underlying porcine growth and fatness traits remains largely unknown. To uncover genetic loci and candidate genes for these traits, we explored the GeneSeek GGP Porcine 80K SNP chip to perform a GWAS for seven growth and fatness traits in 365 individuals from the Sujiang pig, a recently developed breed in China. We identified two, 17, one and 11 SNPs surpassing the suggestively significant threshold (P < 1.86 × 10⁻⁵) for body weight, chest circumference, chest width and backfat thickness respectively. Of these SNPs, 20 represent novel genetic loci, and five and four SNPs were respectively associated with chest circumference and backfat thickness at a genome-wide significant threshold (P < 9.31 × 10⁻⁷). Eight SNPs had a pleiotropic effect on both chest circumference and backfat thickness. The most remarkable locus resided in a region between 72.95 and 76.27 Mb on pig chromosome 4, harboring a number of previously reported quantitative trait loci related to backfat deposition. In addition to two reported genes (PLAG1 and TAS2R38), we identified four genes including GABRB3, ZNF106, XKR4 and MGAM as novel candidates for body weight and backfat thickness at the mapped loci. Our findings provide insights into the genetic architecture of porcine growth and fatness traits and potential markers for selective breeding of Chinese Sujiang pigs.     

A promoter polymorphism of <Emphasis Type="Italic">MSTN</Emphasis> g.−371T>A and its associations with carcass traits in Korean cattle

A promoter polymorphism of bovine Myostatin (MSTN) gene g.−371T>A was screened in Holstein and two Korean indigenous cattle breeds, Hanwoo and Jeju Black cattle (JBC). The MSTN g.−371T>A polymorphism was found in all three cattle breeds tested. An allele MSTN g.−371A was the most frequent in the JBC breed among breeds tested. The association of MSTN genotypes for carcass traits was also tested in the Hanwoo population. Significant differences were found between the genotypes and level of meat quality grade index which converted the marbling score levels (P < 0.05), reflecting the metabolic role of MSTN for inhibition of preadipocyte differentiation in intramuscular fat deposition. In addition, significant differences were found for fat color index of backfat according to MSTN genotypes (P < 0.05), suggesting that MSTN may play a role in deposition of white-yellow adipocytes in backfat. However, there was no detection of significant association of genotypes with the live weight, carcass weight, backfat thickness, eye muscle area, marbling score, or meat color index (P > 0.05). Despite the lack of statistical association, wild type g.−371T/-showed association patterns similar to those of A/A homozygotes, such as heavier weights, thinner backfat, larger eye muscle area, and lower marbling score. The results of the present study suggest that MSTN promoter polymorphism g.−371T>A may affect carcass traits, which could be a useful molecular marker for planning improvements in the economic traits of Korean cattle breeds.     

Molecular characterization,chromosomal location,alternative splicing and polymorphism of porcine <Emphasis Type="Italic">GFAT1</Emphasis> gene

Glutamine: fructose-6-phosphate amidotransferase (GFAT) is the rate-limiting enzyme of the hexosamine synthesis pathway, which plays important roles in insulin resistance and glucose toxicity. GFAT1 is one of the two isoenzymes of GFAT. In the present study, we cloned cDNA sequence of the porcine GFAT1 gene and identified a GFAT1 splice variant (designed GFAT1-L) that contains a 54 bp insertion within the coding region. Nested RT–PCR revealed that GFAT1 was ubiquitously expressed in all tested tissues, but GFAT1-L was only expressed in skeletal muscle and heart, not in liver, spleen, lung, kidney, small intestine, stomach and fat tissue, suggested that GFAT1-L was selectively expressed in striate muscle in pig. Using both the somatic cell hybrid panel and radiation hybrid panel, the GFAT1 gene was mapped to porcine chromosome 3q21-q27, in which several significant QTLs for carcass traits were found. Among the SNPs we found in porcine GFAT1 gene, only the g. 101A>G polymorphism which located in intron 8 was polymorphic in two pig populations we investigated in the study. Association analyses revealed that the g. 101A>G polymorphism has a significant effect on lean meat percentage (P < 0.05), corrected backfat thickness (P < 0.05) and backfat at the rump (P < 0.05).     

A novel single nucleotide polymorphism in exon 7 of LPL gene and its association with carcass traits and visceral fat deposition in yak (Bos grunniens) steers

Lipoprotein lipase (LPL) is considered as a key enzyme in the lipid deposition and metabolism in tissues. It is assumed to be a major candidate gene for genetic markers in lipid deposition. Therefore, the polymorphisms of the LPL gene and associations with carcass traits and viscera fat content were examined in 398 individuals from five yak (Bos grunniens) breeds using PCR–SSCP analysis and DNA sequencing. A novel nucleotide polymorphism (SNP)-C→T (nt19913) was identified located in exon 7 in the coding region of the LPL gene, which replacement was responsible for a Phe-to-Ser substitution at amino acid. Two alleles (A and B) and three genotypes designed as AA, AB and BB were detected in the PCR products. The frequencies of allele A were 0.7928, 0.7421, 0.7357, 0.6900 and 0.7083 for Tianzhu white yak (WY), Gannan yak (GY), Qinghai-Plateau yak (PY), Xinjiang yak (XY) and Datong yak (DY), respectively. The SNP loci was in Hardy–Weinberg equilibrium in five yak populations (P > 0.05). Polymorphism of LPL gene was shown to be associated with carcass traits and lipid deposition. Least squares analysis revealed that there was a significant effect on live-weight (LW) (P < 0.01), average daily weight gain (ADG) and carcass weight (P < 0.05). Individuals with genotype BB had lower mean values than those with genotype AA and AB for loin eye area and viscera fat weight (% of LW) in 25–36 months (P < 0.05). The results indicated that LPL gene is a strong candidate gene that affects carcass traits and fat deposition in yak.     

Porcine insulin receptor substrate 4 (<Emphasis Type="Italic">IRS4</Emphasis>) gene: cloning,polymorphism and association study

Using PCR and inverse PCR techniques we obtained a 4,498 bp nucleotide sequence FN424076 encompassing the complete coding sequence of the porcine insulin receptor substrate 4 (IRS4) gene and its proximal promoter. The 1,269 amino acid porcine protein deduced from the nucleotide sequence shares 92% identity with the human IRS4 and possesses the same domains and the same number of tyrosine phosphorylation motifs as the human protein. We detected substitution FN424076:g.96C<G in the promoter region that segregates in Meishan and a synonymous substitution FN424076:g.1829T<C in the coding sequence with allele C present only in Meishan. Linkage mapping placed the IRS4 gene at position 82 cM on the current USDA–USMARC linkage map of porcine chromosome X. Association analyses were performed on 555 animals of 12th–15th generation of the Meishan × Large White cross and showed that both SNPs were highly significantly associated with backfat depth (P = 0.0005) and that the SNP FN424076:g1829T<C was also associated with loin depth (P = 0.017). The Meishan alleles increased back fat depth and decreased loin depth. IRS4 can be considered a positional candidate gene for at least some of the QTL located at the centromeric region of porcine chromosome X.     

Molecular characterization and association analysis of porcine adipose triglyceride lipase (<Emphasis Type="Italic">PNPLA2</Emphasis>) gene

The adipose triglyceride lipase (PNPLA2, also known as ATGL) is a novel triacylglycerol (TG) lipase which specifically removes the first fatty acid from the triglyceride molecule generating free fatty acid and diglyceride (DG) in mammalian cells. Here we describe the molecular characterization of the porcine ATGL gene. The full-length cDNA sequence contains a 1,461 bp open reading frame encoding a protein of 486 amino acids with a calculated molecular mass of 53.2 kDa and an isoelectric point of 7.90. The porcine ATGL protein shares high identity with other mammalian ATGL. The ATGL gene contains 9 coding exons, spans approximately 6 kb. The porcine ATGL mRNA was expressed predominantly in backfat, mildly in muscle, small intestine and heart, and almost absent in liver, spleen, lung, stomach, kidney and ovary. Statistical analysis showed the ATGL gene polymorphism (G/A³⁹²) was different between Chinese indigenous and introduced commercial western pig breeds, and was highly associated with almost all the fat deposition and carcass traits, including subcutaneous fat thickness, viscera adipose tissue, lean percentage, loin eye traits and even rib numbers.     

Confirmed association between a single nucleotide polymorphism in the <Emphasis Type="Italic">FTO</Emphasis> gene and obesity-related traits in heavy pigs

We recently showed that a polymorphism in the fat mass and obesity associated (FTO) gene (AM931150: g.276T > G) is associated with fat deposition traits in pigs. To confirm this result, we genotyped this polymorphism in an Italian Duroc population made up by 313 performance tested pigs with known estimated breeding values (EBVs) for average daily gain, back fat thickness (BFT), feed:gain ratio, lean cuts (LC), and visible intermuscular fat (VIF, a measure of intermuscular fat in the hams). In addition, we genotyped 148 commercial heavy pigs for which several fat deposition traits and lean meat percentage were measured. The results of the association analyses confirmed the effect of the FTO mutation on obesity-related traits (VIF, BFT and LC) in the Italian Duroc pigs (P < 0.01) and in the commercial pigs (intramuscular fat content of different muscles, P < 0.05 or P < 0.10; lean meat content, P < 0.05; BFT, P < 0.05; intermuscular fat content in the hams, P < 0.05).     

Molecular cloning,polymorphism and association analyses of a novel porcine mRNA differentially expressed in the Longissimus muscle tissues from Meishan and Large White pigs

The mRNA differential display technique was performed to investigate the differences of gene expression in the longissimus muscle tissues from Meishan and Large White pigs. One novel mRNA that was differentially expressed was identified through semi-quantitative RT-PCR and the cDNA complete sequence was then obtained using the rapid amplification of cDNA ends (RACE) method. The nucleotide sequence of the mRNA is not homologous to any of the known porcine genes. Sequence prediction analysis revealed that the this mRNA is not protein-coding mRNA. Polymorphism analyses revealed that there was a C-T mutation on the position of 669 bp and PCR -Dra I-RFLP analyses revealed that Chinese indigenous pig breeds and exotic pig breeds displayed obvious genotype and allele frequency differences at this locus. Association analyses revealed that this polymorphic locus was significantly associated with the drip loss rate, skin percentage, meat color value (m.Longissimus Dorsi, LD), loin eye width, loin eye area, water holding capacity, carcass length, caul fat weight, intramuscular fat (m.Longissimus Dorsi, LD), lean meat weight, lean meat percentage, backfat thickness at buttock (P < 0.05).     

New SNP of the porcine Perilipin 2 (<Emphasis Type="Italic">PLIN2</Emphasis>) gene,association with carcass traits and expression analysis in skeletal muscle

PLIN2 (perilipin 2) is a cytosolic protein that promotes the formation and stabilization of the intracellular lipid droplets, organelles involved in the storage of lipid depots. Porcine PLIN2 gene represents a biological and positional candidate for fat deposition, a polygenic trait that affects carcass and meat quality. The aim of the present study was to screen PLIN2 gene for polymorphisms, to evaluate the association with carcass quality traits, and to investigate the gene expression in skeletal muscle. Six new single nucleotide polymorphisms (SNP) were detected by sequencing 32 samples from five pig breeds (Italian Large White, Italian Duroc, Italian Landrace, Belgian Landrace, Pietrain). Two SNP localized in introns, two in the 3′-untranslated region (UTR), and two missense SNP were found in exons. A 3′-UTR mutation (GU461317:g.98G>A), genotyped in 290 Italian Duroc pigs by High Resolution Melting, resulted significantly associated (P < 0.01) with average daily gain, feed conversion ratio, lean cuts and hams weight estimated breeding values. PLIN2 gene expression analysis in skeletal muscle of Italian Large White and Italian Duroc pigs divergent for backfat thickness and visible intermuscular fat showed a trend of higher expression level in pigs with higher intermuscular fat. These results suggest that PLIN2 can be a marker for carcass quality in pigs. Further investigation at both gene and protein level could elucidate its role on fat deposition.     

Isolation and imprinting analysis of the porcine DLX5 gene and its association with carcass traits

Imprinted genes play important roles in mammalian growth and development. However, reports on imprinted genes are limited in livestock. In this study, the complete ORF containing 289 amino acids of the porcine DLX5 gene was obtained. A C-to-T SNP mutation in exon 1 of the DLX5 gene was used to detect imprinting status with an RT-PCR/RFLP test (using HhaI) in eight heterozygous pigs from a population of Large White × Meishan F₁ hybrids. Imprinting analysis showed that the porcine DLX5 gene was maternally expressed in skeletal muscle, fat, lung, spleen, stomach and small intestine, but not imprinted in heart, liver, kidney, uterus, ovary, testicle or pituitary. A PCR–RFLP test was also used to detect the polymorphism in 310 pigs of a Large White × Meishan F₂ resource population. The statistical results showed significant association ( P  < 0.01) of the genotypes and fat meat percentage, carcass length, bone percentage, 6–7 rib fat thickness, average backfat thickness, thorax-waist fat thickness and buttock fat thickness.     

猪ACTA2基因的克隆、表达分析及其与生产性状的关联

为鉴定对猪生产性状有重要影响的新分子标记,文章采用电子克隆结合PCR方法获得了猪肌动蛋白α2(Actin alpha 2, ACTA2)基因编码区序列和部分基因组序列,建立了第2内含子C1554T替换的PCR-HinfⅠ- RFLP基因分型方法,在所检测的7个不同猪群中除大白和梅大群体外,其他群体中均是C等位基因频率高于T等位基因的频率。标记与性状关联分析发现ACTA2基因型与肩部背膘厚、臀部背膘厚、肥肉率、瘦肉率、股二头肌pH和肌内脂肪显著或极显著相关,TT基因型与CC基因型相比具有更高的瘦肉率以及更低的肥肉率和背膘厚。通过Real-time RT-PCR分析发现ACTA2在大白和梅山两个品种猪骨骼肌中的表达量都随着日龄的增加而降低,在各个阶段,梅山猪中的表达量都比大白猪中的表达量高。     

Molecular characterization of the porcine <Emphasis Type="Italic">JHDM1A</Emphasis> gene associated with average daily gain: evaluation its role in skeletal muscle development and growth

JHDM1A, a member of the JHDM (JmjC-domain-containing histone demethylase) family, plays an central role in gene silencing, cell cycle, cell growth and cancer development through histone H3K36 demethylation modification. Here reported the cloning, expression, chromosomal location and association analysis with growth traits of porcine JHDM1A gene. Sequence analysis showed that the porcine JHDM1A gene encodes 1,162 amino acids and contains JmjC, F-box, and CXXC zinc-finger domains, which coding sequence and deduced protein shares 91 and 99% similarity with human JHDM1A, respectively. Spatio-Temporal expression analysis indicated that the mRNA expression of porcine JHDM1A had significantly higher levels in the middle (65 days) and later (90 days) period’s embryo skeletal muscle than that of 33 days, and showed a ubiquitously expression but with the highest abundance in kidney, lung and liver of an adult pig. Radiation hybrid mapping and the following linkage mapping data indicate that JHDM1A maps to 2p17 region of pig chromosome 2 (SSC2). Allele frequency differences were detected in different pig breeds and an association study was performed with a SNP within 3′UTR. The results showed that there is a tendency for allele frequencies to differ between the fast growth breeds (Yorkshire) and slow growth pig breeds (Qingping pigs, Yushan Black pigs, Erhualian pigs and Dahuabai pigs). The association analysis using a Berkshire × Yorkshire F₂ population indicated that the C224G polymorphism had a highly significant association with average daily gain on test (P < 0.01), a trend association with average back fat thickness (P < 0.07), and significant associations (P < 0.01) on percent of average drip loss, Fiber Type II Ratio, muscle shear force and average lactate content in μmol/g. This study provides the first evidence that JHDM1A is differentially expressed in porcine embryonic skeletal muscle and associated with meat growth and quality traits.     

Isolation,mapping, SNP detection and association with backfat traits of the porcine <Emphasis Type="Italic">CTNNBL1</Emphasis> and <Emphasis Type="Italic">DGAT2</Emphasis> genes

Both the CTNNBL1 (catenin, β-like1) and DGAT2 (diacylglycerol acyltransferase2) genes play important roles in adipose metabolism. In this study, we cloned these two genes in pigs. Semi-quantitative RT-PCR results showed that both genes were extensively expressed, and CTNNBL1 was at a high level in the heart and spleen, while DGAT2 was most abundant in the liver. In CTNNBL1, one synonymous mutation c.555C>T was identified in the coding region, and association analysis showed that different genotypes of CTNNBL1 were significantly associated with backfat at the shoulder and backfat at the rump (P < 0.05). In 3′-UTR of DGAT2, an A/G variation was detected by the Bcn I PCR-RFLP method, and different genotypes were significantly associated with backfat between the 6th and 7th ribs (P < 0.05). The allele frequency was tested among 188 unrelated pigs from six breeds. The results showed that for CTNNBL1, the Chinese indigenous breeds had higher frequencies of the C allele whereas the western breed had higher frequency of the T allele; and for DGAT2, allele A or G were distributed with no obvious difference in allele frequency. IMpRH was employed to localize these two genes, and CTNNBL1 was assigned to SSC17q21-23 and DGAT2 was assigned to SSC9p23-p24. The results suggest that the porcine CTNNBL1 and DGAT2 genes affect porcine fat deposition and further investigation will be necessary to illustrate the underlying mechanisms.     

Characterization of <Emphasis Type="Italic">methionine adenosyltransferase 2β</Emphasis> gene expression in skeletal muscle and subcutaneous adipose tissue from obese and lean pigs

Methionine adenosyltransferase (MAT) catalyzes the biosynthesis of S-adenosylmethionine. Two genes (MAT1A and MAT2A) encode for the catalytic subunit of MAT, while a third gene (MAT2β) encodes for a regulatory subunit (MAT II β) that regulates the activity of the MAT2A-encoded isoenzyme and intracellular S-adenosylmethionine levels. Our previous work identified MAT2β as a candidate gene for intramuscular fat (IMF) deposition in porcine skeletal muscle by microarray technology. Here, we cloned porcine MAT2β cDNA and compared its expression pattern in subcutaneous adipose tissue and skeletal muscle from obese (Rongchang Breed) and lean (Pig Improvement Company, PIC) pigs (n = 6). The porcine MAT2β cDNA was 1,800 bp long and encodes for 334 amino acids sharing high similarity with other species. MAT2β is expressed at a higher level in liver and duodenum, followed by the stomach, fat and longissinus dorsi muscle. As expected, both subcutaneous fat content and IMF content were higher in obese than in lean pigs (both P < 0.01). MAT2β mRNA abundance was lower in both subcutaneous adipose tissue and skeletal muscle in obese pigs compared with lean pigs (both P < 0.01). MAT II β protein content was lower in skeletal muscle in obese than in lean pigs (P < 0.05), whereas the opposite was observed in subcutaneous adipose tissue (P < 0.01). These data demonstrated an obesity-related expression variation of the MAT II β subunit in skeletal muscle and adipose tissue in pigs, and suggest a novel role for the MAT2β gene in regulation of IMF deposition in skeletal muscle.     

Functional and association studies of the cholesteryl ester transfer protein (CETP) gene in a Wannan Black pig model

Some polymorphisms of the human CETP gene are causally and significantly associated with serum lipids levels; however, the information regarding this gene in pigs is sparse. To evaluate the effects of CETP on blood lipid traits and fat deposition in pig, porcine CETP tissue expression patterns were observed by quantitative real‐time polymerase chain reaction (qPCR) first. High expression was detected in liver, spleen, gluteus medius (GM) muscle and backfat. A de novo polymorphism (AF333037:g.795C>T) in the intron 1 region of porcine CETP was identified. This polymorphism was further genotyped by direct sequencing of the PCR products of 390 Wannan Black pigs, a Chinese native breed population. Association analyses at 45 and 300 days of age revealed highly significant associations between CETP genotypes and serum lipid traits. Furthermore, this polymorphism was proved to be associated with differences in liver CETP mRNA levels: pigs at 300 days of age with the TT genotype had higher levels than did those with other genotypes (P = 0.021). Additionally, analysis at 300 days of age showed that GM CETP mRNA expression correlated positively with serum lipids levels as well as with carcass backfat thickness and intramuscular fat content in GM. These results indicate that CETP is involved in serum, adipose and muscle lipid metabolism in pigs. The mechanisms underlying such relationships and their functional implications are worthy of further research.     

Expression profiling analysis for genes related to meat quality and carcass traits during postnatal development of backfat in two pig breeds

The competitive equilibrium of fatty acid biosynthesis and oxidation in vivo determines porcine subcutaneous fat thickness (SFT) and intramuscular fat (IMF) content. Obese and lean-type pig breeds show obvious differences in adipose deposition; however, the molecular mechanism underlying this phenotypic variation remains unclear. We used pathway-focused oligo microarray studies to examine the expression changes of 140 genes associated with meat quality and carcass traits in backfat at five growth stages (1–5 months) of Landrace (a leaner, Western breed) and Taihu pigs (a fatty, indigenous, Chinese breed). Variance analysis (ANOVA) revealed that differences in the expression of 25 genes in Landrace pigs were significant (FDR adjusted permutation, P<0.05) among 5 growth stages. Gene class test (GCT) indicated that a gene-group was very significant between 2 pig breeds across 5 growth stages (P _ErmineJ<0.01), which consisted of 23 genes encoding enzymes and regulatory proteins associated with lipid and steroid metabolism. These findings suggest that the distinct differences in fat deposition ability between Landrace and Taihu pigs may closely correlate with the expression changes of these genes. Clustering analysis revealed a very high level of significance (FDR adjusted, P<0.01) for 2 gene expression patterns in Landrace pigs and a high level of significance (FDR adjusted, P<0.05) for 2 gene expression patterns in Taihu pigs. Also, expression patterns of genes were more diversified in Taihu pigs than those in Landrace pigs, which suggests that the regulatory mechanism of micro-effect polygenes in adipocytes may be more complex in Taihu pigs than in Landrace pigs. Based on a dynamic Bayesian network (DBN) model, gene regulatory networks (GRNs) were reconstructed from time-series data for each pig breed. These two GRNs initially revealed the distinct differences in physiological and biochemical aspects of adipose metabolism between the two pig breeds; from these results, some potential key genes could be identified. Quantitative, real-time RT-PCR (QRT-PCR) was used to verify the microarray data for five modulated genes, and a good correlation between the two measures of expression was observed for both 2 pig breeds at different growth stages (R=0.874±0.071). These results highlight some possible candidate genes for porcine fat characteristics and provide some data on which to base further study of the molecular basis of adipose metabolism.