RESUMEN
Bama Xiang and Landrace pigs are the local fatty and lean breeds, respectively, in China. We compared differences in carcass traits, meat quality traits, and myosin heavy chain (MyHC) types in the longissimus dorsi muscles between Bama Xiang and Landrace pigs. This was done in pigs of the same age, using real-time PCR, to investigate the relationship between MyHC fiber types and carcass characteristics, meat quality traits, and the key factors regulating muscle fiber type. Bama Xiang pigs exhibited smaller size and slower growth than Landrace pigs (P < 0.01). We found that the superior meat quality, especially the high intramuscular fat (IMF) content in Bama Xiang pig, was related to elevated type I oxidative muscle fiber content (P < 0.01). In contrast, Landrace pig muscle had a higher glycolytic type IIb muscle fiber content (P < 0.01). MyHC I gene expression was significantly positively correlated with backfat thickness and IMF content (P < 0.01). MyHC IIb was significantly negatively correlated with IMF content (P < 0.05), and positively correlated with carcass yield (P < 0.05). AMP-activated protein kinase and peroxisome proliferator-activated receptor-g coactivator-1a are suggested to be the two key factors regulating muscle fiber type in pigs. Our results indicate that muscle fiber composition is one of the key differences leading to the differences of meat quality between Bama Xiang and Landrace pigs. These results may provide a theoretical basis for further studies of the molecular mechanism underlying the excellent meat quality of the Bama Xiang pig.
Asunto(s)
Carne/normas , Fibras Musculares Esqueléticas/fisiología , Cadenas Pesadas de Miosina/genética , Porcinos/fisiología , Proteínas Quinasas Activadas por AMP/genética , Animales , Peso Corporal/genética , Cruzamiento , China , Expresión Génica , Fibras Musculares Esqueléticas/metabolismo , Cadenas Pesadas de Miosina/biosíntesis , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/genética , ARN Mensajero/genética , Porcinos/metabolismo , Factores de Transcripción/genéticaRESUMEN
Lipoprotein lipase (LPL) is a key enzyme in lipid metabolism. This study investigated LPL gene expression, LPL enzyme activity, and the correlation of each with intramuscular fat (IMF) in Chinese Guangxi san-huang (GXSH) and Arbor Acres (AA) chickens. The results showed that age and breed had significant effects on LPL expression and enzyme activity. Correlation analyses showed significant positive correlations between LPL expression levels and IMF contents in the breast and thigh tissues of both GXSH (r = 0.712, P = 0.001; r = 0.792, P < 0.001, respectively) and AA (r = 0.644, P < 0.001; r = 0.545, P < 0.001, respectively) chickens. The results also indicated a significant positive correlation between LPL enzyme activity and IMF contents in the breast and thigh tissues of both GXSH (r = 0.615, P = 0.001; r = 0.685, P < 0.001, respectively) and AA (r = 0.600, P = 0.001; r = 0.528, P = 0.003, respectively) chickens. The results indicated that the LPL gene was significantly correlated with IMF in these two breeds. The results presented here could contribute to knowledge of LPL mRNA developmental expression patterns and enzyme activity, and it could facilitate further research on the molecular mechanisms underlying IMF deposition in chickens.
Asunto(s)
Pollos/genética , Lipoproteína Lipasa/genética , Carne/normas , Tejido Adiposo/metabolismo , Animales , Lipoproteína Lipasa/metabolismo , Músculo Esquelético/metabolismoRESUMEN
Matrix metallopeptidase 1 (MMP-1) has been reported to be involved in the coexistence of type 2 diabetes mellitus (T2DM) and coronary heart disease (CHD). We sought to examine the association between the MMP-1 gene polymorphism and coexistence of T2DM and CHD in a Han Chinese population. We extracted genomic DNA from the peripheral blood of 794 subjects, including 378 patients with coexisting T2DM and CHD and 416 healthy controls. We selected several single nucleotide polymorphisms of the MMP-1 gene and genotyped them using the MassARRAY system, before analyzing the data with Haploview 4.0 and SPSS 20.0. A statistical difference was found in the distribution of rs1799750 genotypes between the patient and control groups (P = 0.041). The frequency of the 2G/2G genotype was 44.25 and 37.0% among patients and control subjects, respectively. Moreover, the frequency of the 2G allele was 65.9% among patients and 59.6% in the control group, and this difference was found to be significant (P = 0.010). Elevated body mass index was also associated with the 2G/2G genotype. Thus, MMP-1 rs1799750 may be involved in the development of coexisting T2DM and CHD in the Han Chinese population.
Asunto(s)
Enfermedad Coronaria/genética , Diabetes Mellitus Tipo 2/genética , Estudios de Asociación Genética , Metaloproteinasa 1 de la Matriz/genética , Adulto , Anciano , Alelos , Pueblo Asiatico , Enfermedad Coronaria/complicaciones , Enfermedad Coronaria/patología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/patología , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Persona de Mediana EdadRESUMEN
In the present study, the complete mitochondrial (mt) genome of Cyclemys dentata was determined using PCR reactions. The structural organization and gene order of C. dentata were equivalent to those of most other vertebrates. The mt genome was 16,489 bp in length, has rich A+T content, consisting of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a control region (D-loop). All protein-coding genes started with ATG, many genes have complete stop codons, except ND2, COX3, ND3, and cyt-b genes had incomplete stop codons of T. The light-strand replication origin (OL) of C. dentata might fold into a stable stem-loop secondary structure, and its loop had 2 nt less than that of the Cyclemys atripons OL sequence. The D-Loop of C. dentata contained a central domain (CD), 2 extended termination associated sequences (ETAS1, ETAS2) and 3 conserved sequence blocks (CSB1, CSB2, CSB3). The average length of 20 turtles' mt genomes was 16,692.5 bp, including 34.1% A, 27.0% T, 26.0% C and 12.9% G. The C. dentata mitochondrial genome could provide useful data for further studies on phylogenetics and conservation genetics of this species. The phylogenetic relationships of the family Geoemydidae were analyzed by maximum-likelihood (ML) and neighbor-joining (NJ) based on concatenated sequences of 13 protein-coding genes from 20 turtle species. The ML and NJ trees had homologous topologies. The results support the existing classification of the genera of Geoemydidae, that C. dentata was a sister species of C. atripons, Pyxidea nested in Cuora, and Chinemys was synonymous with Mauremys.