RESUMO
In this study, we report the investigation of extracellular fatty acid binding protein gene (Ex-FABP) genetic polymorphism in a sample of 360 chicken individuals. The screening of the coding regions with their intron-exon boundaries and the proximal flanking regions was performed through a PCR-SSCP strategy. Following sequence analysis revealed 35 novel single nucleotide polymorphisms (SNPs) of chicken Ex-FABP gene. Among the 35 SNPs, twenty-five were found in the introns. And the remaining seven and three SNPs were in the coding region and the 5'UTR, respectively. Two SNPs in the coding region caused two missense mutants and the other five did not result in any amino acid changes. The nature and the distribution of Ex-FABP mutations in three chicken breeds were analyzed. Variations detected here might have an impact on Ex-FABP activity and function and underpin the development of gene markers for chicken fatty deposition and metabolism. The polymorphism, generated by C4715T mutation in exon5, was significantly associated with thickness of subcutaneous fat plus skin in cocks. Subcutaneous fat plus skin of cocks was more thick in TT genotype than in CC genotype (P < 0.05). The Ex-FABP gene could be a candidate locus or linked to a QTL that significantly affects fatty deposition and metabolism in chicken.
Assuntos
Proteínas Aviárias/genética , Galinhas/genética , Proteínas de Ligação a Ácido Graxo/genética , Lipocalinas/genética , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genética , Gordura Subcutânea/metabolismo , Animais , Proteínas Aviárias/metabolismo , Primers do DNA/genética , Proteínas de Ligação a Ácido Graxo/metabolismo , Estudos de Associação Genética/veterinária , Marcadores Genéticos/genética , Lipocalinas/metabolismo , Mutação de Sentido Incorreto/genética , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita SimplesRESUMO
Novel flowerlike nanostructures consisting of MgO nanofibers were successfully synthesized by a simple chemical route with H(2)O at 950 degrees C in an Ar atmosphere. Various durations of heating gave different growth stages that led to varied product morphologies. The synthesized products were systematically studied by X-ray powder diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and energy-dispersive X-ray analysis. The results show that the nucleation and growth process of the nanoflowers seems to be a vapor-solid mechanism, and that the total heating time during the reaction process is a critical factor for the development of MgO nanoflowers. Initially, Mg particles formed on the Si substrate, followed by the formation of MgO clusters as nucleation centers on the magnesium melt surface and the nucleation of short MgO nanofibers, then growth of the MgO nanofibers occurred, and finally MgO nanoflowers were formed. Besides nanoflowers, novel hierarchical MgO nanostructures were also observed. These nanostructures may be used as three-dimensional composite materials and as supports for other materials.
