Project description:Low protein diets supplied during the growing period of pigs can diminish their growth rate and increase the intramuscular fat (IMF) content which affects the sensorial and technological characteristics of the traits. In the present study, the effects of a low protein diet supplied during the growing diet of Duroc x Iberian crossbred pigs on several phenotypic traits and liver and longissimus dorsi transcriptome, were analysed 20 days after the differential treatment was started (EARLY) and at the end of it (FINAL). A total of 20 crossbred pigs were assigned to two different dietary treatments during the growing period: a control diet (C) and a low protein diet (LP) with the same energy and lower levels of raw protein (11%) and lysine (0.60%). The transcriptomes of liver and longissimus dorsi were quantified through RNAseq. A total of 134 differentially expressed annotated genes and new isoforms (DEGs) between C and LP diets in liver of EARLY animals; 480 DEGs in liver of LATE animals, and 128 DEGs and 68 DEGs in longissimus dorsi of EARLY and LATE animals were detected. The functional analyses revealed that low protein diet diminishes the expression in liver of genes codifying for proteins involved in immune system both in EARLY and LATE animals, affects the expression of genes involved in cholesterol homeostasis in liver and in the energy process and growth in longissimus dorsi. Pigs fed with LP diet had not higher IMF content than C ones, although some lipogenesis genes such as FASN, SCD or SREBF1 were higher expressed on their liver. A low protein diet supplied during growing period affects multiple biological process that could compromise the immune and energy state of the Duroc x Iberian crossbred pigs. These results point out that we should be very cautious before implementing this type of regime in Duroc x Iberian pigs.
Project description:We studied the influence of genetic type (pure Iberian pigs vs crossbred with Duroc) on l.dorsi transcriptome Background: The two main genetic types in Iberian pig production show important phenotypic differences in growth, fattening and tissue composition since early developmental stages. The objective of this work was the evaluation of muscle transcriptome profile in young animals of both genetic types, in order to identify genes, pathways and transcription factors responsible of their phenotypic differences. Contemporary families coming from pure Iberian pigs (IB) or from crossing with Duroc boars (DUxIB) were generated. Piglets (14 from each genetic type) were sacrificed at weaning (28 days) and longissimus dorsi muscle was sampled for composition and gene expression studies. RNA was obtained and hybridized to Affymetrix Porcine Genechip expression arrays. Results: Loin muscle composition showed significant differences between genetic types in intramuscular fat content (6% vs. 4.2% in IB and DUxIB animals, respectively, P=0.009) and in saturated and monounsaturated fatty acid contents (P=0.019 and P=0.044, respectively). Statistical analysis of gene expression data allowed the identification of 256 differentially expressed (DE) genes between genetic types (FDR<0.10), 102 upregulated in IB and 154 upregulated in DUxIB. The size of the effects ranged between 1.2x and 7.8x. Transcript differences were validated for a subset of DE genes by qPCR. Some candidate genes with known effects on muscle growth were found among the DE genes upregulated in DUxIB (IGF2, collagens, integrins). Genes related to lipid metabolism and proteolysis were found among the genes upregulated in IB (ME1, ELOVL6, caspases, catepsins, ubiquitination proteins). We observed alteration in biological functions related to extracellular matrix organization, cellular adhesion, muscle growth and lipid metabolism. Transcription factors (TF) potentially involved in the expression differences found were identified by calculating the regulatory impact factors (RIF). Sixteen TF were found, some of them with known relationship with muscle development (MSTN, SIX4), adipogenesis (CEBPD, PPARGC1B), or extracellular matrix processes (MAX, MXI1). Correlation among the expression of these TF and DE genes show relevant differences between genetic types. Conclusion: The results contribute valuable information about molecular mechanisms determining the phenotypic differences of growth and meat quality between the genetic types studied, mainly related to the development and function of the extracellular matrix and also to some metabolic processes as proteolysis and lipid metabolism. 28 male piglets were employed. 14 animals coming for pure Iberian parents and 14 coming from the crossing of Duroc boars with Iberian sows. Animals were sacrificed at 28 d of age. At the sacrifice, longissimus dorsi muscle tissue was sampled from each animal.
Project description:We performed DNA methylation analysis of the longissimus dorsi (LD) muscle between two development stages (120 and 240 days after birth) in Laiwu pigs, an indigenous fatty pig breed in North China. This study provides a reference for exploring methylation regulation mechanisms affecting fat deposition in obese pigs.
Project description:We performed transcriptome analysis of the longissimus dorsi (LD) muscle during four development stages (60, 120, 240 and 400 days after birth) in Laiwu pigs, an indigenous fatty pig breed in North China. This study provides a reference for exploring transcriptome regulation mechanisms affecting muscle growth and development in obese pigs.
Project description:Iberian ham production includes both purebred (IB) and Duroc-crossbred (IBxDU) Iberian pigs, which show important differences in meat quality and production traits, such as muscle growth and fatness. This experiment was conducted to investigate gene expression differences that could be associated with the observed phenotypic differences between IB and IBxDU pigs. Nine IB and 10 IBxDU pigs were slaughtered at birth, and seven IB and 10 IBxDU at four months of age (growing period). Muscle transcriptome was analyzed on LD samples with RNA-Seq technology. We detected 261 differentially expressed genes between IB and IBxDU neonates and 113 at growth (p < 0.01 and Fold-Change > 1. 5). Newborns transcriptome reflected a highly proliferative developmental stage, while older pigs showed upregulation of catabolic and muscle functioning processes. Regarding the genetic type effect, IBxDU newborns showed enrichment of gene pathways involved in muscle growth, in agreement with the higher prenatal growth observed in these pigs. However, IB growing pigs showed enrichment of pathways involved in protein deposition and cellular growth, supporting the catch-up growth experienced by IB pigs during this period. Moreover, newborn and growing IB pigs showed more active glucose and lipid metabolism than IBxDU pigs.
Project description:Longissimus dorsi muscle transcriptome in pure (Iberian x Iberian) and crossbred (Iberian x Large White) pig fetuses at gestation day 77
Project description:The aim of this study was to identify differentially expressed genes and pathways in longissimus dorsi (LD) of pigs at 40 and 70 d of gestation (stages encompassing the transition from primary to secondary fiber formation) in U.S. commercial crossbred pigs (Yorkshire x Landrace) and Brazilian native Piau pigs. We confirmed the expression patterns for a subset of genes by qRT-PCR. Pathway analysis revealed functionally related genes, and indicated commonalities and differences between the breed types and developmental ages evaluated. Results from qRT-PCR analysis confirmed the expression patterns observed on the array for most of the genes tested (85%). This study reveals transcriptional profiles in LD at 40 and 70 d gestation for commercial and Piau pigs, which helps elucidate phenotypic differences between these breed types.
Project description:The aim of this study was to identify differentially expressed genes and pathways in longissimus dorsi (LD) of pigs at 40 and 70 d of gestation (stages encompassing the transition from primary to secondary fiber formation) in U.S. commercial crossbred pigs (Yorkshire x Landrace) and Brazilian native Piau pigs. We confirmed the expression patterns for a subset of genes by qRT-PCR. Pathway analysis revealed functionally related genes, and indicated commonalities and differences between the breed types and developmental ages evaluated. Results from qRT-PCR analysis confirmed the expression patterns observed on the array for most of the genes tested (85%). This study reveals transcriptional profiles in LD at 40 and 70 d gestation for commercial and Piau pigs, which helps elucidate phenotypic differences between these breed types. This study utilized the Swine Protein-Annotated Oligonucleotide Microarray which contains 20,400 70-mer oligonucleotides (http://www.pigoligoarray.org). Total RNA was isolated from fetuses obtained from gilts at each gestational age (n=3 crossbred gilts; n=4 Piau gilts) and RNA from 3 fetuses per litter was pooled. Samples were evaluated with a connected loop design using 13 slides such that six breed comparisons and seven age comparisons were performed. Fluorescence intensity data was LOESS normalized and analyzed with a mixed model.