RESUMO
The objective of this study was to determine hepatic expression levels of GHR, IGF1R, IGF1 and IGF2 genes in young growing gilts at different developmental ages (60-210 days) in five pig breeds: Polish Large White (PLW), Polish Landrace (PL), Pulawska (Pul), Duroc (Dur) and Pietrain (Pie). We studied the differences among pig breeds as well as within each breed for pigs in different developmental ages. Obtained results revealed major differences among breeds in hepatic gene expression of porcine GHR, IGF1R, IGF1 and IGF2 genes in different developmental ages. The differences among breeds of GHR expression were significantly higher in PLW, PL at the age of 60, 90, 120 days as compared to Pul, Dur and Pie. In turn, the highest level of IGF1R expression was observed in PL at age of 150, 180 and 210 days, whereas in case of IGF1 the highest level was recorded in Pie gilts at the age of 60 and 90 days. Moreover trait associated study revealed highly significant correlations between hepatic expressions of IGF1R and IGF2 genes and carcass composition traits (P < 0.01) The results of study suggest that porcine GHR, IGF1R, IGF1 and IGF2 genes may be potential candidate genes for postnatal growth and carcass composition traits. Therefore, the implementation of the hepatic expression of GH/IGF genes into the pig breeding and gene assisted selection program in different pig breeds should be considered. However, further population wide study is needed to clarify the hepatic expression association with economic traits, such as body growth, meat quality and carcass composition traits.
Assuntos
Cruzamento/métodos , Fígado/metabolismo , Receptores de Somatomedina/metabolismo , Receptores da Somatotropina/metabolismo , Somatomedinas/metabolismo , Sus scrofa/crescimento & desenvolvimento , Sus scrofa/genética , Fatores Etários , Animais , Composição Corporal/genética , Primers do DNA/genética , Feminino , Modelos Lineares , Carne , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Especificidade da Espécie , Sus scrofa/metabolismoRESUMO
MYOG and MYF6 belong to the MyoD gene family. They code for the bHLH transcription factors playing a key role in later stages of myogenesis: differentiation and maturation of myotubes. Three SNPs in porcine MYF6 and two in porcine MYOG were analysed in order to establish associations with chosen carcass quality and growth rate traits in Polish Landrace, Polish Large White and line 990 sows. No statistically significant effect of SNP in the promoter region of the MYF6 gene on its expression measured on mRNA level was found. Associations between the genotype at the MYF6 locus and carcass quality traits appeared to be breed-dependent. The C allele in the case of SNP in the promoter region and GC haplotype in exon 1 were advantageous for right carcass side weight in Polish Landrace sows and disadvantageous for this trait in Polish Large White sows. These gene variants were also the most advantageous for loin and ham weight in sows of line 990. The mutation in exon 1 of the MYOG gene had no statistically significant association with carcass quality traits and the mutation in the 3'-flanking region had the breed-dependent effect as well. These results suggest that SNPs analysed in this study are not causative mutations, but can be considered as markers of some other, still unrevealed genetic polymorphism that influences the physiological processes and phenotypic traits considered in this study.
Assuntos
Fatores de Regulação Miogênica/genética , Miogenina/genética , Sus scrofa/genética , Animais , Feminino , Expressão Gênica , Genótipo , Desenvolvimento Muscular/genética , Músculo Esquelético/metabolismo , Polimorfismo de Nucleotídeo Único , Especificidade da Espécie , Sus scrofa/crescimento & desenvolvimentoRESUMO
Myogenic factor 5 (myf-5) is the product of the MYF5 gene, belonging to the MyoD family. This transcription factor participates in the control of myogenesis. We identified 3 new mutations in the promoter region of the gene: A65C, C580T and C613T. The aim of this study was to evaluate the influence of the A65C transversion on gene expression. The analysis was conducted on 15 Polish Large White gilts. The relative content of MYF5 mRNA in m. longissimus dorsi did not differ significantly across MYF5 genotypes (AA, AC, CC). This result suggests that the A65C transversion may not play an important role in the expression of the MYF5 gene in analysed adult muscle but it abolishes a putative binding site for two transcription factors (CDP and HSF1) and creates such a site for Sp1.
Assuntos
Fator Regulador Miogênico 5/genética , Polimorfismo de Nucleotídeo Único/genética , Regiões Promotoras Genéticas/genética , Substituição de Aminoácidos , Animais , Sítios de Ligação , Cistina Difosfato/genética , Cistina Difosfato/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição de Choque Térmico , Músculo Esquelético/metabolismo , Polônia , Fator de Transcrição Sp1/genética , Fator de Transcrição Sp1/metabolismo , Suínos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Myogenin is a gene belonging to the MyoD family, which codes for the bHLH transcription factor playing a key role in myogenesis. It affects the processes of differentiation and maturation of myotubes during embryogenesis. Fragments of the porcine myogenin coding sequence and promoter region were amplified and subjected to MSSCP analysis. T-->C transition recognised by the MaeIII restriction enzyme in exon 1 was revealed, which appeared to be a silent mutation in the region of the transactivation domain. No other polymorphism was found either in the remaining coding sequence or the promoter region.
Assuntos
Miogenina/genética , Polimorfismo Conformacional de Fita Simples , Sus scrofa/genética , Animais , Primers do DNA , Éxons/genética , PolôniaRESUMO
Myogenic factor 3 (myf - 3) and myogenic factor 5 (myf - 5) are the products of genes: MYOD1 (MYF3) and MYF5, respectively, which belong to the MyoD family. These transcription factors control the processes of myogenesis. The fragments of both the genes comprising exons and promoters were amplified and sequenced. In the 5'UTR region of gene MYOD1, the G302A transition was identified and it is not recognized by any restriction endonuclease. In the promoter region of gene MYF5 we identified three mutations at positions: A65C (PCR-RFLP/AciI); C580T (PCR-RFLP/FokI) and C613T (PCR-RFLP/HinPI). Mutations C580T and C613T were characteristic for Pietrain x (Polish Large White x Polish Landrace) crossbred pigs named Torhyb. The C2931T transition, which is not recognized by any restriction enzyme, was identified in exon 3 of gene MYF5. This mutation results in a change of the amino acid sequence (Leu-->Pro). The frequency of particular genotypes at the MYOD1 and MYF5 loci proved to be dependent on pig breed. However, Duroc pigs were monomorphic at all the SNPs presented in this study. These SNPs might be analyzed in a further study as probably influencing carcass meatiness.
Assuntos
Regiões 5' não Traduzidas/genética , Proteínas de Ligação a DNA/genética , Proteínas Musculares/genética , Proteína MyoD/genética , Polimorfismo de Nucleotídeo Único/genética , Transativadores/genética , Substituição de Aminoácidos , Animais , Sequência de Bases , Primers do DNA , Éxons/genética , Fator Regulador Miogênico 5 , Polônia , Regiões Promotoras Genéticas/genética , SuínosRESUMO
An assessment was made of the genetic variation of the Pulawska pig through the determination of polymorphism of 6 genes and 14 microsatellite sequences. The examinations covered 52 gilts included in a preservation breeding project. The identification of the alleles at microsatellite loci was performed in an ABI PRISM 310 GENETIC ANALYZER. Gene polymorphism was established by the PCR-RLFP method. On the basis of the variation of 6 genes and 14 microsatellites the mean value of the heterozygosity coefficient was estimated at 0.61, while the value of the corresponding PIC coefficient (polymorphism information content) amounted to 0.55. The probability that the genotypes of two randomly chosen individuals in a population are identical was: 6.95 x 10(-3) (based on gene allele frequency) and 1.23 x 10(-14) (based on microsatellite allele frequency).