RESUMO
The FABP4 and FABP5 genes, coding for fatty acid transport proteins, have long been studied as positional candidate genes for SSC4 QTL affecting fat deposition and composition traits in pigs. Polymorphisms in these genes, FABP4:g.2634_2635insC and FABP5:g.3000T>G, have previously been associated with fatness traits in an Iberian by Landrace cross (IBMAP). The aim of the present work was to evaluate the functional implication of these genetic variants. For this purpose, FABP4 and FABP5 mRNA expression levels in 114 BC1_LD animals (25% Iberian × 75% Landrace) were analyzed using real-time quantitative PCR in backfat and muscle. FABP4 gene expression in backfat, but not in muscle, was associated with FABP4:g.2634_2635insC. In contrast, FABP5:g.3000T>G was not associated with gene expression levels. An expression-based genome-wide association study highlighted the FABP4:g.2634_2635insC polymorphism as the polymorphism most associated with FABP4 gene expression in backfat. Furthermore, other genomic regions associated in trans with the mRNA expression of FABP4 in backfat and FABP5 in muscle were also identified. Finally, two putative transcription binding sites for PPARG and NR4A2 may be affected by the FABP4:g.2634_2635insC polymorphism, modifying FABP4 gene expression. Our results reinforce FABP4 as a candidate gene for fatness traits on SSC4.
Assuntos
Adiposidade/genética , Proteínas de Ligação a Ácido Graxo/genética , Locos de Características Quantitativas , Sus scrofa/genética , Tecido Adiposo/metabolismo , Animais , Sítios de Ligação , Feminino , Expressão Gênica , Estudos de Associação Genética , Genótipo , Masculino , Músculo Esquelético/metabolismo , Fatores de Transcrição/metabolismoRESUMO
RNA-Seq technology is widely used in quantitative gene expression studies and identification of non-annotated transcripts. However this technology also can be used for polymorphism detection and RNA editing in transcribed regions in an efficient and cost-effective way. This study used SNP data from an RNA-Seq assay to identify genes and mutations underlying production trait variations in an experimental pig population. The hypothalamic and hepatic transcriptomes of nine extreme animals for growth and fatness from an (Iberian × Landrace) × Landrace backcross were analyzed by RNA-Seq methodology, and SNP calling was conducted. More than 125 000 single nucleotide variants (SNVs) were identified in each tissue, and 78% were considered to be potential SNPs, those SNVs segregating in the context of this study. Potential informative SNPs were detected by considering those showing a homozygous or heterozygous genotype in one extreme group and the alternative genotype in the other group. In this way, 4396 and 1862 informative SNPs were detected in hypothalamus and liver respectively. Out of the 32 SNPs selected for validation, 25 (80%) were confirmed as actual SNPs. Association analyses for growth, fatness and premium cut yields with 19 selected SNPs were carried out, and four potential causal genes (RETSAT, COPA, RNMT and PALMD) were identified. Interestingly, new RNA editing modifications were detected and validated for the NR3C1:g.102797 (ss1985401074) and ACSM2B:g.13374 (ss1985401075) positions and for the COG3:g3.4525 (ss1985401087) modification previously identified across vertebrates, which could lead to phenotypic variation and should be further investigated.
Assuntos
Carne , Polimorfismo de Nucleotídeo Único , Edição de RNA , Análise de Sequência de RNA/métodos , Sus scrofa/genética , Animais , Cruzamentos Genéticos , Feminino , Masculino , Sus scrofa/fisiologiaRESUMO
APOA2 is a protein implicated in triglyceride, fatty acid and glucose metabolism. In pigs, the APOA2 gene is located on pig chromosome 4 (SSC4) in a QTL region affecting fatty acid composition, fatness and growth traits. In this study, we evaluated APOA2 as a candidate gene for meat quality traits in an Iberian × Landrace backcross population. The APOA2:c.131T>A polymorphism, located in exon 3 of APOA2 and determining a missense mutation, was associated with the percentage of hexadecenoic acid [C16:1(n-9)], linoleic acid [C18:2(n-6)], α-linolenic acid [C18:3(n-3)], dihomo-gamma-linolenic acid [C20:3(n-6)] and polyunsaturated fatty acids (PUFAs) in backfat. Furthermore, this SNP was associated with the global mRNA expression levels of APOA2 in liver and was used as a marker to determine allelic expression imbalance by pyrosequencing. We determined an overexpression of the T allele in heterozygous samples with a mean ratio of 2.8 (T/A), observing a high variability in the allelic expression among individuals. This result suggests that complex regulatory mechanisms, beyond a single polymorphism (e.g. epigenetic effects or multiple cis-acting polymorphisms), may be regulating APOA2 gene expression.
Assuntos
Apolipoproteína A-II/genética , Ácidos Graxos/química , Carne , Sus scrofa/genética , Tecido Adiposo/química , Alelos , Animais , Cruzamentos Genéticos , Expressão Gênica , Estudos de Associação Genética , Genótipo , Fígado/metabolismo , Mutação de Sentido Incorreto , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Locos de Características Quantitativas , Análise de Sequência de DNARESUMO
Suppressive subtractive hybridization libraries from oviduct at 62 h post-mating of two lines of rabbits divergently selected for uterine capacity were generated to identify differentially expressed genes. A total of 438 singletons and 126 contigs were obtained by cluster assembly and sequence alignment of 704 expressed sequence tags (ESTs), of which 54% showed homology to known proteins of the non-redundant NCBI databases. Differential screening by dot blot validated 71 ESTs, of which 47 showed similarity to known genes. Transcripts of genes were functionally annotated in the molecular function and the biological process gene ontology categories using the BLAST2GO software and were assigned to reproductive developmental process, immune response, amino acid metabolism and degradation, response to stress and apoptosis terms. Finally, three interesting genes, PGR, HSD17B4 and ERO1L, were identified as overexpressed in the low line using RT-qPCR. Our study provides a list of candidate genes that can be useful to understanding the molecular mechanisms underlying the phenotypic differences observed in early embryo survival and development traits.
Assuntos
Etiquetas de Sequências Expressas , Hibridização Genética , Oviductos/metabolismo , Animais , Clonagem Molecular , Bases de Dados Genéticas , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Biblioteca Gênica , Hibridização de Ácido Nucleico , Coelhos , Reação em Cadeia da Polimerase em Tempo Real , Alinhamento de Sequência , Análise de Sequência de DNARESUMO
This study aimed at identifying differential gene expression conditional on the fatty acid profile of the longissimus thoracis (Lt) muscle, a prime cut of economic relevance for fresh and cured pork production. A population of 110 Iberian (25%) × Landrace (75%) back-crossed pigs was used, because these two breeds exhibit extreme profiles of intramuscular saturated fatty acid, monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) contents. Total RNA from Lt muscle was individually hybridized to GeneChip Porcine Genome arrays (Affymetrix). A principal component analysis was performed with data from the 110 animals to select 40 extreme animals based on the total fatty acid profile and the MUFA composition (MAP). Comparison of global transcription levels between extreme fatty acid profile pigs (n = 40) resulted in 219 differentially expressed probes (false discovery rate <0.10). Gene ontology, pathway and network analysis indicated that animals with higher percentages of PUFA exhibit a shift toward a more oxidative muscular metabolism state, with a raise in mitochondria function (PPARGC1A, ATF2), fatty acid uptake and oxidation (FABP5, MGLL). On the other hand, 87 probes were differentially expressed between MUFA composition groups (n = 40; false discovery rate <0.10). In particular, muscles rich in n-7 MUFA expressed higher levels of genes involved in lipid metabolism (GLUL, CRAT, PLA2G15) and lower levels of fatty acid elongation genes (ELOVL5). Moreover, the chromosomal position of FABP5, PAQR3, MGLL, PPARGC1A, GLUL and ELOVL5 co-localized with very relevant QTL for fat deposition and composition described in the same resource population. This study represents a complementary approach to identifying genes underlying these QTL effects.
Assuntos
Composição Corporal/genética , Ácidos Graxos/análise , Músculo Esquelético/química , Sus scrofa/genética , Sus scrofa/metabolismo , Animais , Cruzamento/métodos , Cruzamentos Genéticos , Perfilação da Expressão Gênica/veterinária , Ontologia Genética , Análise de Sequência com Séries de Oligonucleotídeos/veterinária , Análise de Componente Principal , Locos de Características Quantitativas/genética , Reação em Cadeia da Polimerase em Tempo Real/veterináriaRESUMO
The intramuscular fat content and fatty acid composition of porcine meat have a significant impact on its quality and nutritional value. This research aimed to investigate the expression of 45 genes involved in lipid metabolism in the longissimus dorsi muscle of three experimental pig backcrosses, with a 25% of Iberian background. To achieve this objective, we conducted an expression Genome-Wide Association Study (eGWAS) using gene expression levels in muscle measured by high-throughput real-time qPCR for 45 target genes and genotypes from the PorcineSNP60 BeadChip or Axiom Porcine Genotyping Array and 65 single nucleotide polymorphisms (SNPs) located in 20 genes genotyped by a custom-designed Taqman OpenArray in a cohort of 354 animals. The eGWAS analysis identified 301 eSNPs associated with 18 candidate genes (ANK2, APOE, ARNT, CIITA, CPT1A, EGF, ELOVL6, ELOVL7, FADS3, FASN, GPAT3, NR1D2, NR1H2, PLIN1, PPAP2A, RORA, RXRA and UCP3). Three cis-eQTL (expression quantitative trait loci) were identified for GPAT3, RXRA, and UCP3 genes, which indicates that a genetic polymorphism proximal to the same gene is affecting its expression. Furthermore, 24 trans-eQTLs were detected, and eight candidate regulatory genes were located in these genomic regions. Additionally, two trans-regulatory hotspots in Sus scrofa chromosomes 13 and 15 were identified. Moreover, a co-expression analysis performed on 89 candidate genes and the fatty acid composition revealed the regulatory role of four genes (FABP5, PPARG, SCD, and SREBF1). These genes modulate the levels of α-linolenic, arachidonic, and oleic acids, as well as regulating the expression of other candidate genes associated with lipid metabolism. The findings of this study offer novel insights into the functional regulatory mechanism of genes involved in lipid metabolism, thereby enhancing our understanding of this complex biological process.
Assuntos
Redes Reguladoras de Genes , Estudo de Associação Genômica Ampla , Humanos , Animais , Estudo de Associação Genômica Ampla/veterinária , Metabolismo dos Lipídeos/genética , Genômica , Músculo Esquelético/metabolismo , Ácidos Graxos/análise , Polimorfismo de Nucleotídeo Único , Proteínas de Ligação a Ácido Graxo/genética , Proteínas de Ligação a Ácido Graxo/metabolismoRESUMO
Studies of the variation in recombination rate across the genome provide a better understanding of evolutionary genomics and are also an important step towards mapping and dissecting complex traits in domestic animals. With the recent completion of the porcine genome sequence and the availability of a high-density porcine single nucleotide polymorphism (SNP) array, it is now possible to construct a high-density porcine linkage map and estimate recombination rate across the genome. A total of 416 animals were genotyped with the Porcine SNP60BeadChip, and high-density chromosome linkage maps were constructed using CRI-MAP, assuming the physical order of the Sscrofa10 assembly. The total linkage map length was 2018.79 cM, using 658 meioses and 14,503 SNPs. The estimated average recombination rate across the porcine autosomes was 0.86 cM/Mb. However, a large variation in recombination rate was observed among chromosomes. The estimated average recombination rates (cM/Mb) per chromosome ranged from 0.48 in SSC1 to 1.48 in SSC10, displaying a significant negative correlation with the chromosome sizes. In addition, the analysis of the variation in the recombination rates taking 1-Mb sliding windows has allowed us to demonstrate the variation in recombination rates within chromosomes. In general, a larger recombination rate was observed in the extremes than in the centre of the chromosome. Finally, the ratio between female and male recombination rates was also inferred, obtaining a value of 1.38, with the heterogametic sex having the least recombination.
Assuntos
Mapeamento Cromossômico , Ligação Genética , Recombinação Genética , Suínos/genética , Animais , Cromossomos de Mamíferos , Feminino , Genótipo , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Leptin signalling plays a fundamental role in growth, fatness and body composition. The aim of this study was to investigate the porcine LEP gene sequence in an Iberian × Landrace experimental cross to identify polymorphisms associated with productivity and quality traits. Because of the documented effects on these traits of the LEPR c.1987C>T polymorphism, the LEP and LEPR c.1987C>T polymorphisms and their interactions have been jointly investigated. The LEP gene sequencing has allowed the identification of 39 polymorphisms, eight of which are novel. Three intronic SNPs, LEP g.1382C>T, LEP g.1387C>T and LEP g.1723A>G, have been genotyped, and association analyses have been carried out. Analyses of LEP g.1387C>T, fully linked to LEP g.1382C>T, have revealed additive effects on live and carcass weights and dominant effects on several backfat thickness measurements. Novel effects of both LEP and LEPR polymorphisms on fatty acid composition in subcutaneous fat have been detected, probably mediated through the effects on fatness. The results reported here suggest that the T alleles of both LEP g.1387C>T and LEPR c.1987C>T, which are fixed in the Iberian pigs, would lead to an increase in growth, fatness and saturated fatty acid content in fat, which could be explained by an increased feed intake.
Assuntos
Composição Corporal/genética , Ácidos Graxos/análise , Leptina/genética , Receptores para Leptina/genética , Sus scrofa/genética , Animais , Feminino , Estudos de Associação Genética , Genótipo , Masculino , Carne , Polimorfismo de Nucleotídeo Único , Gordura Subcutânea , Sus scrofa/fisiologiaRESUMO
Long-chain acyl-CoA synthetase (ACSL) family members catalyse the formation of long-chain acyl-CoA from fatty acid, ATP and CoA, thus playing an important role in both de novo lipid synthesis and fatty acid catabolism. Previous studies in our group evaluated ACSL4 as a positional candidate gene for quantitative trait loci located on chromosome X in an Iberian × Landrace cross. A DQ144454:c.2645G>A SNP located in the 3' untranslated region of the ACSL4 gene was associated with the percentages of oleic and monounsaturated fatty acids. The aim of the present work was to evaluate the functional implication of this genetic variant. An expression analysis was performed for 120 individuals with different genotypes for the DQ144454:c.2645G>A polymorphism using real-time quantitative PCR. Differences between genotypes were identified in liver, with the ACSL4 mRNA expression levels higher in animals with the G allele than in animals with the A allele. A SNP genome-wide association study with ACSL4 relative expression levels showed significant positions on chromosomes 6 and 12. Description of positional candidate genes for ACSL4 regulation on chromosomes 6 and 12 is provided.
Assuntos
Coenzima A Ligases/genética , Carne , Sus scrofa/genética , Animais , Mapeamento Cromossômico/veterinária , Cromossomos de Mamíferos/genética , Feminino , Expressão Gênica , Estudos de Associação Genética/veterinária , Variação Genética , Genótipo , Masculino , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Locos de Características Quantitativas , RNA Mensageiro/biossínteseRESUMO
Domestication, modern breeding and artificial selection have shaped dramatically the genomic variability of domestic animals. In livestock, the so-called FAT1 quantitative trait locus (QTL) in porcine chromosome 4 was the first QTL uncovered although, to date, its precise molecular nature has remained elusive. Here, we characterize the nucleotide variability of 13 fragments of â¼500 bp equally spaced in a 2 Mb region in the vicinity of the FAT1 region in a wide-diversity panel of 32 pigs. Asian and European animals, including local Mediterranean and international pig breeds, were sequenced. Patterns of genetic variability were very complex and varied largely across loci and populations; they did not reveal overall a clear signal of a selective sweep in any breed, although FABP4 fragment showed a significantly higher diversity. We used an approximate Bayesian computation approach to infer the evolutionary history of this SSC4 region. Notably, we found that European pig populations have a much lower effective size than their Asian counterparts: in the order of hundreds vs hundreds of thousands. We show also an important part of extant European variability is actually due to introgression of Asian germplasm into Europe. This study shows how a potential loss in diversity caused by bottlenecks and possible selective sweeps associated with domestication and artificial selection can be counterbalanced by migration, making it much more difficult the identification of selection footprints based on naive demographic assumptions. Given the small fragment analyzed here, it remains to be studied how these conclusions apply to the rest of the genome.
Assuntos
Evolução Molecular , Suínos/genética , Animais , Sequência de Bases , Teorema de Bayes , DNA/genética , Genética Populacional , Genótipo , Dados de Sequência Molecular , Polimorfismo Genético , Locos de Características QuantitativasRESUMO
Despite dramatic reduction in sequencing costs with the advent of next generation sequencing technologies, obtaining a complete mammalian genome sequence at sufficient depth is still costly. An alternative is partial sequencing. Here, we have sequenced a reduced representation library of an Iberian sow from the Guadyerbas strain, a highly inbred strain that has been used in numerous QTL studies because of its extreme phenotypic characteristics. Using the Illumina Genome Analyzer II (San Diego, CA, USA), we resequenced â¼ 1% of the genome with average 4 × depth, identifying 68,778 polymorphisms. Of these, 55,457 were putative fixed differences with respect to the assembly, based on the genome of a Duroc pig, and 13,321 were heterozygous positions within Guadyerbas. Despite being highly inbred, the estimate of heterozygosity within Guadyerbas was â¼ 0.78 kb(-1) in autosomes, after correcting for low depth. Nucleotide variability was consistently higher at the telomeric regions than on the rest of the chromosome, likely a result of increased recombination rates. Further, variability was 50% lower in the X-chromosome than in autosomes, which may be explained by a recent bottleneck or by selection. We divided the whole genome in 500 kb windows and we analyzed overrepresented gene ontology terms in regions of low and high variability. Multi organism process, pigmentation and cell killing were overrepresented in high variability regions and metabolic process ontology, within low variability regions. Further, a genome wide Hudson-Kreitman-Aguadé test was carried out per window; overall, variability was in agreement with neutral expectations.
Assuntos
Mapeamento Cromossômico/métodos , Análise de Sequência de DNA/métodos , Suínos/genética , Animais , Sequência de Bases , Feminino , Variação Genética , Genoma , Genômica/métodos , Endogamia , Polimorfismo de Nucleotídeo Único , Alinhamento de SequênciaRESUMO
The serpin peptidase inhibitor, clade A, member 6 gene (SERPINA6), also known as corticosteroid-binding globulin or CBG, is involved in obesity and stress sensitivity. Previous studies have reported putative causal mutations within that gene in the porcine species. To characterize a hypothetical selective footprint, we have resequenced approximately 6 kb of coding and non-coding fragments in 20 pigs comprising domestic breeds and wild boars from Asia and Europe. Nucleotide variability was found to be far greater within Asian pig breeds than European breeds (π = 1% vs. 0.05%, respectively), which is consistent with pig evolutionary history. The putative causal amino acid substitution p.Gly307Arg (SNP c.919G>A) associated with meat quality (drip loss) was only detected in European domestic pig breeds, suggesting a very recent mutation that appeared after domestication in Europe. No support for positive selection was detected, as no reduction in levels of diversity surrounding the mutation was found in lean breeds with respect to wild boar.
Assuntos
Carne/análise , Mutação , Obesidade/genética , Estresse Fisiológico/genética , Transcortina/genética , Substituição de Aminoácidos , Animais , Sequência de Bases , Evolução Biológica , Hidrocortisona/análise , Gado , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , SuínosRESUMO
Models in QTL mapping can be improved by considering all potential variables, i.e. we can use remaining traits other than the trait under study as potential predictors. QTL mapping is often conducted by correcting for a few fixed effects or covariates (e.g. sex, age), although many traits with potential causal relationships between them are recorded. In this work, we evaluate by simulation several procedures to identify optimum models in QTL scans: forward selection, undirected dependency graph and QTL-directed dependency graph (QDG). The latter, QDG, performed better in terms of power and false discovery rate and was applied to fatty acid (FA) composition and fat deposition traits in two pig F2 crosses from China and Spain. Compared with the typical QTL mapping, QDG approach revealed several new QTL. To the contrary, several FA QTL on chromosome 4 (e.g. Palmitic, C16:0; Stearic, C18:0) detected by typical mapping vanished after adjusting for phenotypic covariates in QDG mapping. This suggests that the QTL detected in typical mapping could be indirect. When a QTL is supported by both approaches, there is an increased confidence that the QTL have a primary effect on the corresponding trait. An example is a QTL for C16:1 on chromosome 8. In conclusion, mapping QTL based on causal phenotypic networks can increase power and help to make more biologically sound hypothesis on the genetic architecture of complex traits.
Assuntos
Tecido Adiposo/fisiologia , Ácidos Graxos/genética , Modelos Genéticos , Fenótipo , Locos de Características Quantitativas , Suínos/genética , Animais , Simulação por ComputadorRESUMO
Weaning is a critical period in the life of pigs with repercussions on their health and welfare and on the economy of the swine industry. This study aimed to assess the effect of the commercial early weaning on gut microbiota, intestinal gene expression and serum metabolomic response via an integrated-omic approach combining 16S rRNA gene sequencing, the OpenArray gene expression technology and 1H-NMR spectroscopy. Fourteen piglets from different litters were sampled for blood, jejunum tissue and caecal content two days before (- 2d), and three days after (+ 3d) weaning. A clearly differential ordination of caecal microbiota was observed. Higher abundances of Roseburia, Ruminococcus, Coprococcus, Dorea and Lachnospira genera in weaned piglets compared to prior to weaning showed the quick microbial changes of the piglets' gut microbiota. Downregulation of OCLN, CLDN4, MUC2, MUC13, SLC15A1 and SLC13A1 genes, also evidenced the negative impact of weaning on gut barrier and digestive functions. Metabolomic approach pinpointed significant decreases in choline, LDL, triglycerides, fatty acids, alanine and isoleucine and increases in 3-hydroxybutyrate after weaning. Moreover, the correlation between microbiota and metabolome datasets revealed the existence of metabolic clusters interrelated to different bacterial clusters. Our results demonstrate the impact of weaning stress on the piglet and give insights regarding the associations between gut microbiota and the animal gene activity and metabolic response.
Assuntos
Microbioma Gastrointestinal/genética , Interações entre Hospedeiro e Microrganismos/genética , Animais , Bactérias/genética , Ceco/microbiologia , Fezes/microbiologia , Jejuno/microbiologia , Metaboloma/genética , RNA Ribossômico 16S/genética , Suínos , DesmameRESUMO
The aim of this study was to determine the possible impact of early socialization and an enriched neonatal environment to improve adaptation of piglets to weaning. We hypothesized that changes in the microbiota colonization process and in their metabolic response and intestinal functionality could help the animals face weaning stress. A total of 48 sows and their litters were allotted into a control (CTR) or an enriched treatment (ENR), in which piglets from two adjacent pens were combined and enriched with toys. The pattern of caecal microbial colonization, the jejunal gene expression, the serum metabolome and the intestinal physiology of the piglets were assessed before (-2 d) and after weaning (+ 3d). A differential ordination of caecal microbiota was observed after weaning. Serum metabolome suggested a reduced energetic metabolism in ENR animals, as evidenced by shifts in triglycerides and fatty acids, VLDL/LDL and creatine regions. The TLR2 gene showed to be downregulated in the jejunum of ENR pigs after weaning. The integration of gene expression, metabolome and microbiota datasets confirmed that differences between barren and enriched neonatal environments were evident only after weaning. Our results suggest that improvements in adaptation to weaning could be mediated by a better response to the post-weaning stress.
Assuntos
Ceco/microbiologia , Microbioma Gastrointestinal , Jejuno , Lactação , Animais , Feminino , Jejuno/metabolismo , Jejuno/microbiologia , Suínos , DesmameRESUMO
There is a high interest on gut health in poultry with special focus on consequences of the intestinal diseases, such as coccidiosis and C. perfringens-induced necrotic enteritis (NE). We developed a custom gene expression panel, which could provide a snapshot of gene expression variation under challenging conditions. Ileum gene expression studies were performed through high throughput reverse transcription quantitative real-time polymerase chain reaction. A deep review on the bibliography was done and genes related to intestinal health were selected for barrier function, immune response, oxidation, digestive hormones, nutrient transport, and metabolism. The panel was firstly tested by using a nutritional/Clostridium perfringens model of intestinal barrier failure (induced using commercial reused litter and wheat-based diets without exogenous supplementation of enzymes) and the consistency of results was evaluated by another experiment under a coccidiosis challenge (orally gavaged with a commercial coccidiosis vaccine, 90× vaccine dose). Growth traits and intestinal morphological analysis were performed to check the gut barrier failure occurrence. Results of ileum gene expression showed a higher expression in genes involved in barrier function and nutrient transport in chickens raised in healthy conditions, while genes involved in immune response presented higher expression in C.perfringens-challenged birds. On the other hand, the Eimeria challenge also altered the expression of genes related to barrier function and metabolism, and increased the expression of genes related to immune response and oxidative stress. The panel developed in the current study gives us an overview of genes and pathways involved in broiler response to pathogen challenge. It also allows us to deep into the study of differences in gene expression pattern and magnitude of responses under either a coccidial vaccine or a NE.
Assuntos
Galinhas/microbiologia , Infecções por Clostridium/microbiologia , Enterite/microbiologia , Doenças das Aves Domésticas/microbiologia , Ração Animal/microbiologia , Animais , Infecções por Clostridium/genética , Clostridium perfringens/efeitos dos fármacos , Clostridium perfringens/patogenicidade , Coccidiose/genética , Coccidiose/microbiologia , Coccidiose/prevenção & controle , Suplementos Nutricionais , Eimeria/efeitos dos fármacos , Eimeria/patogenicidade , Enterite/genética , Enterite/prevenção & controle , Expressão Gênica/efeitos dos fármacos , Humanos , Doenças das Aves Domésticas/genética , Doenças das Aves Domésticas/prevenção & controle , Vacinas/farmacologiaRESUMO
We have investigated the origin of swine breeds through the joint analysis of mitochondrial, microsatellite, and Y-chromosome polymorphisms in a sample of pigs and wild boars with a worldwide distribution. Genetic differentiation between pigs and wild boars was remarkably weak, likely as a consequence of a sustained gene flow between both populations. The analysis of nuclear markers evidenced the existence of a close genetic relationship between Near Eastern and European wild boars making it difficult to infer their relative contributions to the gene pool of modern European breeds. Moreover, we have shown that European and Far Eastern pig populations have contributed maternal and paternal lineages to the foundation of African and South American breeds. Although West African pigs from Nigeria and Benin exclusively harbored European alleles, Far Eastern and European genetic signatures of similar intensity were detected in swine breeds from Eastern Africa. This region seems to have been a major point of entry of livestock species in the African continent as a result of the Indian Ocean trade. Finally, South American creole breeds had essentially a European ancestry although Asian Y-chromosome and mitochondrial haplotypes were found in a few Nicaraguan pigs. The existence of Spanish and Portuguese commercial routes linking Asia with America might have favored the introduction of Far Eastern breeds into this continent.
Assuntos
Cruzamento , Cromossomos de Mamíferos/genética , Mitocôndrias/genética , Filogenia , Sus scrofa/genética , Cromossomo Y/genética , África , Animais , Citocromos b/genética , DNA Mitocondrial/genética , Europa (Continente) , Ásia Oriental , Marcadores Genéticos , Geografia , Haplótipos , Heterozigoto , Repetições de Microssatélites/genética , Dados de Sequência Molecular , Polimorfismo Genético , Dinâmica Populacional , Sus scrofa/classificaçãoRESUMO
A total of 598 F2 does from a cross between the high and low lines selected divergently for uterine capacity during 10 generations were used in a candidate gene analysis. The presence of major genes affecting the number of implanted embryos and uterine capacity has been suggested in lines divergently selected for uterine capacity. Uterine capacity is a main component of litter size. The progesterone receptor gene was tested as a candidate gene to determine whether polymorphisms explain differences in litter size and its components. Fragments of the promoter region and exons 1-8 were amplified and sequenced. One SNP was found in the promoter region, 2464G>A, three SNPs in the 5'-UTR exon 1, and a silence SNP in exon 7. The first four SNPs were segregated in two haplotypes. The allele G found in the promoter region was found in 75% of the high-line parental animals and in 29% of the low-line parental animals. The GG genotype had 0.5 kits and 0.5 implanted embryos more than the AA genotype. At 48 hr of gestation, the difference in early embryo survival and embryonic stage of development was small. However, at 72 hr of gestation, the GG genotype had 0.36 embryos more than the AA genotype and also had a more advanced embryonic stage of development, showing a lower percentage of compacted morulae and a higher percentage of blastocysts. The difference in litter size between the GG and GA genotypes was similar to the difference found between homozygote genotypes; however, differences in implanted embryos, early embryo survival, and embryo development were not detected between the GG and GA genotypes.
Assuntos
Embrião de Mamíferos/citologia , Polimorfismo de Nucleotídeo Único/genética , Coelhos/genética , Receptores de Progesterona/genética , Reprodução/genética , Útero/fisiologia , Animais , Embrião de Mamíferos/fisiologia , Feminino , Tamanho da Ninhada de Vivíparos , Masculino , Gravidez , Regiões Promotoras Genéticas/genética , Coelhos/embriologiaRESUMO
Domestic species allow us to study dramatic evolutionary changes at an accelerated rate due to the effectiveness of modern breeding techniques and the availability of breeds that have undergone distinct selection pressures. We present a worldwide survey of haplotype variability around a known causative mutation in porcine gene IGF2, which increases lean content. We genotyped 34 SNPs spanning 27 kb in 237 domestic pigs and 162 wild boars. Although the selective process had wiped out variability for at least 27 kb in the haplotypes carrying the mutation, there was no indication of an overall reduction in genetic variability of international vs. European local breeds; there was also no evidence of a reduction in variability caused by domestication. The haplotype structure and a plot of Tajima's D against the frequency of the causative mutation across breeds suggested a temporal pattern, where each breed corresponded to a different selective stage. This was observed comparing the haplotype neighbor-joining (NJ) trees of breeds that have undergone increasing selection pressures for leanness, e.g., European local breeds vs. Pietrain. These results anticipate that comparing current domestic breeds will decisively help to recover the genetic history of domestication and contemporary selective processes.
Assuntos
Variação Genética , Haplótipos , Fator de Crescimento Insulin-Like II/genética , Mutação/genética , Seleção Genética , Sus scrofa/genética , Animais , Sequência de Bases , Frequência do Gene , Desequilíbrio de Ligação/genética , Dados de Sequência Molecular , Filogenia , Polimorfismo de Nucleotídeo Único/genética , Alinhamento de SequênciaRESUMO
Despite the economic interest of the fatty acid profile in pigs, no gene has been convincingly associated with this trait so far. Here, the porcine microsomal triglyceride transfer protein (MTTP) gene, which plays a crucial role in the assembly of nascent lipoproteins, has been analysed as a positional candidate gene for a QTL affecting the fatty acid composition that was previously identified on chromosome 8 in an Iberian by Landrace F(2) cross. By resequencing a panel of different breeds, a non-synonymous polymorphism in a conserved residue of the lipid transfer domain of MTTP was identified. Association analyses with this polymorphism showed a strong association with the fatty acid composition of porcine fat, much stronger than the QTL effect, in the F(2) cross and in a synthetic Sino-European line. In addition, in vitro activity assays in liver protein extracts have shown that this mutation is also associated with the lipid transfer activity of the MTTP protein (P < 0.1). These results suggest that the detected polymorphism is a potential causal factor of the fatty acid composition QTL. There appears to be an interaction between the porcine MTTP genotype and the type of fat source in the pig diet, which would agree with the previous results on the biology of MTTP biology.