Pigs Of Large White Breed Research Articles

Динаміка вмісту загальних ліпідів у еритроцитах свиней різних типів вищої нервової діяльності за дії стресових факторів

Динаміка вмісту загальних ліпідів у еритроцитах свиней різних типів вищої нервової діяльності за дії стресових факторів

Estimation of (co)variance components for age at first farrowing and farrowing interval in Czech Large White

We aimed to estimate the variance and covariance components for the original and transformed age at the first farrowing (AFF) and farrowing interval in this study. The data from 25,094 sows (77,544 observations) of the Czech Large White pig breed between January 2000 and December 2015 provided by Czech Pig Breeders Association were used for the analyses. Data higher than the median were only transformed. The farrowing interval was evaluated separately from the first to the fourth parity (FI1–FI4). The heritabilities for the original traits were very low: 0.17, 0.11, 0.07, 0.06, and 0.06 for AFF and FI1–FI4, whereas those for the transformed traits were higher: 0.19, 0.14, 0.11, 0.11, and 0.12 for AFF and FI1–FI4, respectively. The phenotypic correlations between the traits were low, but significant. The estimated genetic correlations between all the farrowing intervals were clearly lower than one, indicating that all the farrowing intervals should be treated as different traits. Using the transformation procedure decreased the skewness and kurtosis of the original data in our study. The heritabilities of the analysed farrowing intervals were only increased owing to the transformation.

P5063 The effect of the IGF2 gene on pork and fat quality traits in two populations of the South African Landrace and Large White pig breeds

P5063 The effect of the IGF2 gene on pork and fat quality traits in two populations of the South African Landrace and Large White pig breeds

P5063 The effect of the IGF2 gene on pork and fat quality traits in two populations of the South African Landrace and Large White pig breeds

P5063 The effect of the IGF2 gene on pork and fat quality traits in two populations of the South African Landrace and Large White pig breeds

Estimation of genetic parameters for teat number and reproduction and production traits from different data sources for Czech dam breeds

Genetic parameters for total number of teats (TNT), total number of piglets born (TNB), number of weaned piglets (NW), lean meat content, and average daily gain were estimated for the populations of Czech Large White and Czech Landrace pig breeds. TNT was defined as sum of all measurable teats without taking into account of between teats and was counted during the identification of piglets up to 10 days after birth. Two main resources of data for TNT were analyzed: (1) TNT recorded only for breeding pigs in the national performance testing scheme (animals with at least 14 teats in total) as the pre-selected performance data set (PT; 94,500 animals); and (2) TNT recorded in nucleus and multiplier farms (F). In this data set (40,160 animals), whole litter information, including negatively selected piglets, was considered. Only 6.7% of animals from farmers’ data set showed optimal production in the performance test. The average number of piglets evaluated in the PT and F data sets per litter was 2.7 and 9.4, respectively. The TNT was analyzed using single-trait and five-trait animal models by using production and reproduction data to determine heritability and genetic correlations between TNT and production and reproduction traits. As expected, the farmers’ data set was characterized by higher variability of TNT than the performance data set. The estimated heritability for TNT ranged from 0.28 to 0.30 (regarding the data and models used). The genetic correlations of TNT with production and reproduction traits were negligible and varied from −0.096 to 0.080 depending on the datasets and models used. A very high significant genetic correlation (0.782 and 0.793) was found between TNB and NW. Our hypothesis of impact of raw data inclusion on estimated genetic parameters for the trait TNT was rejected. Our findings suggested no significant differences for the estimated heritabilities of TNT among the analyzed datasets and models. The breeding values for TNT can be estimated by using single as well as multi-trait animal models, because no genetic correlations with production and reproduction traits were found.

Association between leptin receptor gene polymorphism and quality of both meat and back fat in large white pigs of ukrainian breeding

Leptin receptor is one of the components of the system of regulating energy homeostasis of the organism. Leptin receptor gene (LEPR) polymorphism is associated with pig carcass index of the content of intramus- cular fat in its valuable parts, which is particularly important when assessing the quality of their carcasses for processing. Intramuscular fat is associated with meat fl avor characteristics and partly determines its tenderness, juiciness, and other parameters. Aim. To analyze LEPR gene (SNP NM001024587.1, p. 1987 C > T) polymor- phism in populations of various pig breeds and to establish its relationship with the quality of both meat and fat of pigs of Large White breed of Ukrainian breeding. Methods. Genetic-population analysis of nine pig breeds, associative analysis on the search connection of LEPR gene polymorphism with quality of both meat and fat of pigs of Large White breed of Ukrainian breeding. LEPR locus genotyping was performed by High Resolution Melting (HRM). Results. All the studied breeds are characterized by polymorphism of the leptin receptor gene (SNP NM001024587.1, p. 1987 C > T), signifi cant breed specifi city in the distribution of frequencies of alleles was established. Statistically confi rmed effect (p < 0.05) of genotypes LEPR on the content of intramuscular fat, total dry matter and moisture in the meat, as well as the moisture content in the back fat of pigs of Ukrainian Large White breed was revealed. Higher content of intramuscular fat was found in the animals with genotype TT, while a smaller amount of intramuscular fat and more moisture in fat was revealed in heterozygotes. Conclusions. Genetic marker LEPR SNP NM001024587.1, p. 1987 C > T can be used in the marker-assisted selection to predict and improve the performance quality of the meat of pigs of Large White breed of the Ukrainian breeding. These results suggest that porcine leptin receptor gene controls the quality of fat comp- lex – inside muscles and in the dorsal part of the carcass.

Effect Of Chromium Nicotinate On Oxidative Stability, Chemical Composition And Meat Quality Of Growing-Finishing Pigs

The effect of different organic sources of Cr on growth, feed efficiency and carcass value is known but there is a lack of information between chromium nicotinate (CrNic) and pork quality. Therefore, purpose of this research was to investigate the effects of CrNic on chemical composition, quality and oxidative stability of pork meat. In the study, pigs of Large White breed (40 pcs) were used. The pigs were divided into two groups, namely the control and the experimental of 20 pcs with equal number of barrows and gilts. The pigs were fed the same diet which consisted of three feed mixtures applied at the different growth phases, from 30 - 45 kg OS-03, 45 - 70 kg OS-04 and 70 - 100 kg OS-05. The pigs were allowed ad libitum access to feed and water. The diet of experimental group was supplemented with 0.75 mg.kg-1 CrNic in the form of chromium-inactivated yeast Saccharomyces cerevisiae. The fattening period in pigs lasted from 30 to 100 kg. The chromium supplementation led to a significantly higher content of chromium in longissimus thoracis muscle (LT) of experimental pigs. In addition, the results showed a statistically significant difference (p ≤0.05) in retention of chromium in the LT, monounsaturated and omega-3 polyunsaturated fatty acids content in experimental group compared with control. Moreover, there was highly significant (p £0.05) difference in essential fatty acids, as well as in oxidative stability in 7 days, among the groups. The highly significant differences were also observed among sexes, namely in total water, protein and intramuscular fat contents, colour CIE b* in both times, and oxidative stability. However, physical-technological parameters (pH, drip loss, shear force and meat colour) were not affected when pigs were fed the supplement. On the whole, the positive effect of chromium nicotinate in most of investigated parameters may be beneficial not only for pork industry but also for consumers.

Twenty years of artificial directional selection have shaped the genome of the Italian Large White pig breed.

In this study, we investigated at the genome-wide level if 20years of artificial directional selection based on boar genetic evaluation obtained with a classical BLUP animal model shaped the genome of the Italian Large White pig breed. The most influential boars of this breed (n=192), born from 1992 (the beginning of the selection program of this breed) to 2012, with an estimated breeding value reliability of >0.85, were genotyped with the Illumina Porcine SNP60 BeadChip. After grouping the boars in eight classes according to their year of birth, filtered single nucleotide polymorphisms (SNPs) were used to evaluate the effects of time on genotype frequency changes using multinomial logistic regression models. Of these markers, 493 had a PBonferroni <0.10. However, there was an increasing number of SNPs with a decreasing level of allele frequency changes over time, representing a continuous profile across the genome. The largest proportion of the 493 SNPs was on porcine chromosome (SSC) 7, SSC2, SSC8 and SSC18 for a total of 204 haploblocks. Functional annotations of genomic regions, including the 493 shifted SNPs, reported a few Gene Ontology terms that might underly the biological processes that contributed to increase performances of the pigs over the 20years of the selection program. The obtained results indicated that the genome of the Italian Large White pigs was shaped by a directional selection program derived by the application of methodologies assuming the infinitesimal model that captured a continuous trend of allele frequency changes in the boar population.

Genome-wide study on intramuscular fat in Italian Large White pig breed using the PorcineSNP60 BeadChip.

Genome-wide association study results are presented for intramuscular fat in Italian Large White pig breed. A total of 886 individuals were genotyped with PorcineSNP60 BeadChip. After quality control performed with plink software and in R environment, 49208 markers remained for the association analysis. The genome-wide association studies was conducted using linear mixed model implemented in GenABEL. We detected seven new SNPs of genes till now not found associated to intramuscular fat (IMF). Three markers map in a wide intergenic region rich of QTL linked to fat traits, one map 388kb upstream the gene SDK1, one map inside PPP3CA gene, one inside SCPEP1 gene and the last is not mapped in the porcine genome yet. Associations here presented indicate a moderate effect of these genes on IMF. In particular, PPP3CA, that is involved in the oxidative metabolism of skeletal muscle, could be considerated as an interesting candidate gene for IMF content in pigs. However, further studies are needed to clarify the role of these genes on the physiological processes involved in IMF regulation. These results may be useful to control this trait that is important in terms of nutritional, technological and organoleptic characteristics of fresh meat and processed products.

Comparison of expression levels of fourteen genes involved in the lipid and energy metabolism in two pig breeds

Fat content, fatty acid composition and lean cut weight are important parameters which influence meat and carcass quality in pigs. Up to now, the genes involved in the regulation of the lipid and energy metabolism in porcine skeletal muscle and fat tissue are still relatively unknown. The aim of this study was to investigate the expression levels of fourteen genes (ACACA, ACLY, CES3, ENO3, FASN, INSIG2, LMNA, MTTP, ACVR1C, NAMPT, PLIN1, PLIN2, PLTP and SORT1) mapped on different chromosomes (1, 4, 7, 8, 9, 12, 15 and 17) which were chosen for their involvement in lipid or energy metabolism in porcine muscle and backfat tissue. Tissue samples from Italian Large White and Italian Duroc pig breeds were collected at the slaughterhouse and frozen in liquid nitrogen. After extraction, the mRNA was quantified by quantitative real time polymerase chain reaction (RT-PCR) and the transcription levels of the genes analysed were compared between breeds for each tissue. In the backfat tissue, differences were found for the ACACA, ACLY, and FASN genes whose highest gene expression levels were found in Italian Large White pigs. In addition, a correlation analysis was carried out between the transcription levels of the genes considered in each tissue and breed. Co-expression relationships still relatively unknown were identified, suggesting new associations between genes which in some cases differed between the two breeds. These results suggest differences between Italian Large White and Italian Duroc pig breeds determined at the genome level affecting carcass quality and fat traits.

A retrospective analysis of allele frequency changes of major genes during 20years of selection in the Italian Large White pig breed.

In this study, we investigated whether a selection programme based on boar genetic evaluation obtained with a classical BLUP animal model can change allele frequencies in a pig population. All Italian Large White boars born from 1992 to 2012 with estimated breeding value reliability >0.85 (n=200) were selected among all boars of this breed. Boars were genotyped with markers in major genes (IGF2 intron3-g.3072G>A, MC4R p.D298N, VRTN PRE1 insertion, PRKAG3 p.I199V and FTO g.276T>G). Genotyping data were analysed grouping boars in eight classes according to their year of birth. To evaluate the influence of time on allele frequencies of the genotyped markers, multinomial logistic regression models were computed. Four of five polymorphic sites (IGF2, MC4R, VRTN and FTO) showed significant (p<0.01) changes in allele frequencies over time due to a progressive and continuous increase of one allele (associated with higher lean meat content, higher average daily gain and favourable feed: gain ratio) and, consequently, decrease of the other one, following the directional selection of the selection programme of this pig breed. The retrospective analysis that was carried out in Italian Large White boars suggests that selection based on methodologies assuming the infinitesimal model is able to modify in a quite short period of time allele frequencies in major genes, increasing the frequency of alleles explaining a relevant (non-infinitesimal) fraction of the overall genetic variability for production traits.

A genome-wide association study of limb bone length using a Large White × Minzhu intercross population.

BackgroundIn pig, limb bone length influences ham yield and body height to a great extent and has important economic implications for pig industry. In this study, an intercross population was constructed between the indigenous Chinese Minzhu pig breed and the western commercial Large White pig breed to examine the genetic basis for variation in limb bone length. The aim of this study was to detect potential genetic variants associated with porcine limb bone length.MethodsA total of 571 F2 individuals from a Large White and Minzhu intercross population were genotyped using the Illumina PorcineSNP60K Beadchip, and phenotyped for femur length (FL), humerus length (HL), hipbone length (HIPL), scapula length (SL), tibia length (TL), and ulna length (UL). A genome-wide association study was performed by applying the previously reported approach of genome-wide rapid association using mixed model and regression. Statistical significance of the associations was based on Bonferroni-corrected P-values.ResultsA total of 39 significant SNPs were mapped to a 11.93 Mb long region on pig chromosome 7 (SSC7). Linkage analysis of these significant SNPs revealed three haplotype blocks of 495 kb, 376 kb and 492 kb, respectively, in the 11.93 Mb region. Annotation based on the pig reference genome identified 15 genes that were located near or contained the significant SNPs in these linkage disequilibrium intervals. Conditioned analysis revealed that four SNPs, one on SSC2 and three on SSC4, showed significant associations with SL and HL, respectively.ConclusionsAnalysis of the 15 annotated genes that were identified in these three haplotype blocks indicated that HMGA1 and PPARD, which are expressed in limbs and influence chondrocyte cell growth and differentiation, could be considered as relevant biological candidates for limb bone length in pig, with potential applications in breeding programs. Our results may also be useful for the study of the mechanisms that underlie human limb length and body height.Electronic supplementary materialThe online version of this article (doi:10.1186/s12711-014-0056-6) contains supplementary material, which is available to authorized users.

Single-nucleotide polymorphism analysis of GH, GHR, and IGF-1 genes in minipigs

Tibetan (TB) and Bama (BM) miniature pigs are two popular pig breeds that are used as experimental animals in China due to their small body size. Here, we analyzed single-nucleotide polymorphisms (SNPs) in gene fragments that are closely related to growth traits [growth hormone (GH), growth hormone receptor (GHR), and insulin-like growth factor (IGF)-1)] in these pig breeds and a large white (LW) control pig breed. On the basis of the analysis of 100 BMs, 108 TBs, and 50 LWs, the polymorphic distribution levels of GH, GHR, and IGF-1 were significantly different among these three pig breeds. According to correlation analyses between SNPs and five growth traits - body weight (BW), body length (BL), withers height (WH), chest circumference (CC), and abdomen circumference (AC) - three SNP loci in BMs and four SNP loci in TBs significantly affected growth traits. Three SNP sites in BMs and four SNP sites in TBs significantly affected growth traits. SNPs located in the GH gene fragment significantly affected BL and CC at locus 12 and BL at locus 45 in BMs, and also BW, WH, CC, and AC at locus 45 and WH and CC at locus 93 in TBs. One SNP at locus 85 in the BM GHR gene fragment significantly affected all growth traits. All indices were significantly reduced with a mixture of alleles at locus 85. These results provide more information regarding the genetic background of these minipig species and indicate useful selection markers for pig breeding programs.

Sirt1 Inhibits Akt2-Mediated Porcine Adipogenesis Potentially by Direct Protein-Protein Interaction

Compared with the rodent, the domestic pig is a much better animal model for studying adipogenesis and obesity-related diseases. Currently, the role of Akt2 and Sirt1 in porcine adipogenesis remains elusive. In this study, we defined the effect of Akt2 and Sirt1 on porcine preadipocyte lipogenesis and the regulatory mechanism. First, we found that Akt2 was widely expressed in porcine various tissues and at high level in adipose tissue. Further analysis showed that the expression level of Akt2 was much higher in adipose tissue and adipocytes of the Bamei pig breed (a Chinese indigenous fatty pig) than in that of the Large White pig breed (a Lean type pig), whereas the level of Sirt1 expression was opposite. The expression levels of Sirt1 and Akt2 gradually increased during adipogenic differentiation. Adipogenesis was robustly inhibited in Akt2 deficient fat cells, whereas it was promoted in Sirt1 deficient cells using the lentiviral–mediated shRNA approach. Interestingly, adipogenesis returned to normal in Akt2 and Sirt1 dual–deficient cells, showing that the pro- and anti–adipogenic effects were balanced. Sirt1 inhibited transcriptional activity of Akt2 in a dose-dependent way. Interaction of endogenous Akt2 and Sirt1 was gradually enhanced before day 6 of differentiation, and then attenuated. Akt2 and Sirt1 also interacted with C/EBPα in adipocytes. Moreover, knockdown of Akt2 or/and Sirt1 affected pro–lipogenesis of insulin–stimulated by PI3K/Akt pathway. We further found that Sirt1 respectively interacted with PI3K and GSK3β which were key upstream and downstream components of PI3K/Akt pathway. Based on the above findings, we concluded that the crosstalk between C/EBPα and PI3K/Akt signaling pathways is implicated in Akt2 and Sirt1 regulation of adipogenesis.

Study of swine alpha-macroglobulin gene-family polymorphism in the context of some problems of animal breeding

Long-term screening of Siberian populations of the Large White pig breed has been performed using a set of allotypic markers of the alpha-macroglobulin system (AM). An effect of differentiating selection on AM haplotypes—namely, on the presentation of the AM1.2 haplotype controlling the polymorphism of closely linked genes (A1M and A2M)—was detected in animals of different breeding and producing groups. It is suggested that this process may involve other genes both present in pig chromosome 5 in linkage disequilibrium with the studied genes and linked to this haplotype by structural and functional coadaptivity: 1. A cluster of eight genes encoding taste-perception receptors (TASTE) located directly between the AMR6-A2M genes. 2. Four clusters including more than 100 genes encoding olfactory-signal receptors (OLFACTORY), which appear to be coadapted with TASTE genes. 3. Two functionally polymorphic genes encoding cytidine deaminase (APOBEC3-APOBEC3F) flanking the A1M-AMR1 region and predetermining the resistance to retroviral infections. 4. At least two QTL-loci (21DWT and BF60K), which define similar morphometric parameters, including height, development, and mass increase at different developmental stages of piglets associated with the homeobox (HOX) and herculin (MYF6) genes, respectively, located at different ends of the chromosome. The haploblocks partially overlap in various combinations, and the tightest overlap was recorded in the AM-family region. It is assumed that selection vectors of each haploblocks are differently directed. The selection involves large tracts of the chromosome rather than individual genes or gene families. The compositions and allele sets of these tracts are balanced by natural selection and long-term animal breeding.

Amylase and phosphatase activity in tissues cecum in growing purebred and crossbred piglets

Defined active α-amylase, alkaline and acid phosphatases in the tissues of three parts cecum (proximal, medial and distal) in growing pigs. The highest activity of the studied enzymes in the tissues of all parts of the intestine studied in pigs of large white breed and crossbred determined: α-amylase — a three-week and six-month, alkaline phosphatase — a two-week, acid phosphatase — in two-, three-and four-week.

ОЦЕНКА ВКЛАДА РАЗЛИЧНЫХ ПОПУЛЯЦИЙ В ГЕНЕТИЧЕСКОЕ РАЗНООБРАЗИЕ СВИНЕЙ КОРНЯ КРУПНОЙ БЕЛОЙ ПОРОДЫ

The characteristic of the allele pool of the Large White and Yorkshire pig breeds using 11 microsatellites (S0155, S0355, S0386, SW72, SW951, S0101, SW240, SW857, S0228, SW911 and SW936) was done. The study was performed on 17 pig populations of Russian, Danish, Hungarian, Canadian, Lithuanian, German, Ukrainian and French origins ( n = 837). The data were analyzed using GenAlEx (v. 6.4), Structure (v. 2.3.1) and Past (v. 2.15) software. It was shown that 24.2 per cent of the total microsatellite diversity was due to intra population differences (R st = 0.242, p = 0.01). Based on F stand R st (AMOVA) values the greater contribution of geographically distant and local populations into microsatellites diversity was observed. The cluster analysis performed according J.K. Pritchard (2000) and M. Nei (1983) showed that the cluster structure was in concordance with populations’ origin.

Molecular characterization, expression analysis and association study with meat quality traits of porcine TTID gene

Titin immunoglobulin domain protein (TTID) is localized to the Z-line and binds to alpha-actinin, gamma-filamin. It plays an indispensable role in stabilization and anchorage of thin filaments. In this study, the full-length cDNA sequence was isolated by the reverse transcription-polymerase chain reaction (RT-PCR) and the rapid amplification of cDNA ends (RACE). The TTID sequence was deposited into the Genbank under the accession no. DQ157551. The deduced protein of 499 amino acids showed 93% identity to the corresponding human and rat sequence. Semi-quantitative RT-PCR revealed porcine TTID gene was expressed highest level in skeletal muscle, at second-highest level in the heart, but only low expression in the fat was detected. Bioinformatics analysis shows the molecular weight of the TTID protein is 55.747kD with a PI of 9.26. It contains the protein function site of two potential Ig-like domain profiles, six N-myristoylation sites, six potential Casein kinase II phosphorylation sites, eight protein kinase C phosphorylation sites, three N-glycosylation sites, a tyrosine kinase phosphorylation site and a cell attachment sequence site. No putative base substitution was detected in the coding region by comparing sequences of Large White, Landrace and Meishan pig breeds. A T978C single nucleotide polymorphism in the intron 6 of porcine TTID gene was detected by a HinfI PCR-restriction fragment length polymorphism. Study showed allele frequency differences among four purebreds. Association of the genotypes with meat quality traits showed that different genotypes of porcine TTID gene were significantly associated with meat pH (m.Biceps Femoris) (P<0.05), meat color value (m.longissimus Dorsi) (P<0.05) and Water Moisture (m.longissimus Dorsi) (P<0.05).

Microsatellite mapping of quantitative trait loci affecting female reproductive tract characteristics in Meishan × Large White F2 pigs1

A QTL analysis of female reproductive data from a 3-generation experimental cross between Meishan and Large White pig breeds is presented. Six F(1) boars and 23 F(1) sows, progeny of 6 Large White boars and 6 Meishan sows, produced 502 F(2) gilts whose reproductive tract was collected after slaughter at 30 d of gestation. Five traits [i.e., the total weight of the reproductive tract, of the empty uterine horns, of the ovaries (WOV), and of the embryos], as well as the length of uterine horns (LUH), were measured and analyzed with and without adjustment for litter size. Animals were genotyped for a total of 137 markers covering the entire porcine genome. Analyses were carried out based on interval mapping methods, using a line-cross regression and a half-full sib maximum likelihood test. A total of 18 genome-wide significant (P < 0.05) QTL were detected on 9 different chromosomes (i.e., SSC 1, 5, 6, 7, 9, 12, 13, 18, and X). Five genome-wide significant QTL were detected for LUH, 4 for weight of the empty uterine horns and WOV, 2 for total weight of the reproductive tract, and 1 for weight of the embryos. Twenty-two additional suggestive QTL were also detected. The largest effects were obtained for LUH and WOV on SSC13 (9.2 and 7.0% of trait phenotypic variance, respectively). Meishan alleles had both positive (e.g., on SSC7) and negative effects (e.g., on SSC13) on the traits investigated. Moreover, the QTL were generally not fixed in founder breeds, and opposite effects were in some cases obtained in different families. Although reproductive tract characteristics had only a moderate correlation with reproductive performances, most of the major QTL detected in this study were previously reported as affecting female reproduction, generally with reduced significance levels. This study thus shows that focusing on traits with high heritability might help to detect loci involved in low heritability major traits for breeding.

Discovery of Porcine microRNAs in Multiple Tissues by a Solexa Deep Sequencing Approach

The domestic pig (Sus scrofa) is an important economic animal for meat production and as a suitable model organism for comparative genomics and biomedical studies. In an effort to gain further identification of miRNAs in the pig, we have applied the Illumina Solexa sequencing technology to carry out an in-depth analysis of the miRNA transcriptome in a pool of equal amounts of RNA from 16 different porcine tissues. From this data set, we identified 437 conserved and 86 candidate novel miRNA/miRNA* in the pig, corresponding to 329 miRNA genes. Compared with all the reported porcine miRNAs, the result showed that 112 conserved and 61 candidate novel porcine miRNA were first reported in this study. Further analysis revealed extensive sequence variations (isomiRs) of porcine miRNAs, including terminal isomiRs at both the 5′ and 3′ ends and nucleotide variants. Read counts of individual porcine miRNA spanned from a few reads to approximately 405541 reads, confirming the different level of expression of porcine miRNAs. Subsequently, the tissue expression patterns of 8 miRNAs were characterized by Northern blotting. The results showed that miR-145, miR-423-5p, miR-320, miR-26a, and miR-191 are ubiquitously expressed in diverse tissues, while miR-92, miR-200a, and miR-375 were selectively enriched and expressed in special tissues. Meanwhile, the expression of 8 novel porcine-specific miRNAs was validated by stem-loop RT-PCR, and one of these was detected by Northern blotting. Using the porcine miRNA array designed according to our Solexa results, 123 miRNAs were detected expression in porcine liver tissues. A total of 58 miRNAs showed differential expression between the Tongcheng (a Chinese indigenous fatty breed) and Large White pig breeds (a lean type pig). Taken together, our results add new information to existing data on porcine miRNAs and should be useful for investigating the biological functions of miRNAs in pig and other species.