RESUMEN
The temporal and spatial patterns of Smad and Yes-associated protein 1 (YAP1) expression were investigated in skeletal muscle (gastrocnemius muscle and extensor digitorum longus) at different growth stages (2 days old, 2 and 6 months old) in Hu sheep. Smads were differentially expressed in sheep skeletal muscle, with high expression in the gastrocnemius muscle and lower expression in the extensor digitorum longus. Expression of Smad2, Smad3, and Smad4 at the 2-day-old stage was significantly higher than at other stages (P < 0.05). The expression of Smad7 in 2-day-old sheep was lower than in 6-month-old sheep, with the lowest levels at 2 months. Smad expression was higher in males than in females at the 2-day-old stage, and expression in 2- and 6-month-old males was lower than that in 2-day-old females. Smad3 expression was higher in the 2-day- and 2-month-old males than in the females. There was a positive correlation (P < 0.01) between YAP1 and Smad2 expression in gastrocnemius muscle at the 2-month-old stage. YAP1 and Smad4/7 expression were positively correlated (P < 0.01) in extensor digitorum longus at the 2-day-old stage. YAP1 expression was negatively correlated with Smad7 in the extensor digitorum longus at 6 months. A significant difference between Smad2 and Smad3 (P < 0.01) expression in muscle was observed, consistent with Smad3 and Smad4 expression, indicating that these inhibit transforming growth factor-ß signaling in the same way. There was a positive correlation (P < 0.01) between YAP1 and MSTN expression, suggesting that YAP1 participates in muscle growth in sheep.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Envejecimiento/genética , Músculo Esquelético/metabolismo , Proteína Smad2/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Envejecimiento/metabolismo , Animales , Animales Recién Nacidos , Femenino , Regulación del Desarrollo de la Expresión Génica , Masculino , Músculo Esquelético/crecimiento & desarrollo , Miostatina/genética , Miostatina/metabolismo , Ovinos , Oveja Doméstica , Transducción de Señal , Proteína Smad2/metabolismo , Proteína smad3/genética , Proteína smad3/metabolismo , Proteína Smad4/genética , Proteína Smad4/metabolismo , Proteína smad7/genética , Proteína smad7/metabolismo , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
The aim of this study was to detect candidate genes for the development of hair follicles in the Hu sheep breed. Seven genes have been detected in large, medium, and small wave follicles of Hu sheep using gene chip technology. The histological features of the follicles of newborn Hu-lambs were combined with fluorescence quantitative PCR technology to detect the correlation between the expression of the seven genes and hair follicle development. Among the genes studied, matrix metalloproteinase 2 (MMP2), bone morphogenetic protein-7 (BMP7), and sideroflexin 1 (SFXN1) showed a significantly different pattern of expression in large, medium, and small wave follicles (P < 0.05). The expression of MMP2 had a significant positive correlation with secondary follicles in large waves (P < 0.05), while the expression of BMP7 had a significant correlation with primary follicle diameter in small wave follicles, and a highly significant positive correlation with the number of secondary follicles in the small waves (P < 0.01). The expression of SFXN1 was significantly and positively correlated with the diameters of small wave primary follicles; it also showed a highly significant positive correlation with secondary follicle diameters. Although other genes are associated with hair follicles, their expression in large, medium, and small wave follicles was not significant. We propose that BMP7, MMP2, and SFXN1 genes could be important candidate genes for use in breeding Hu lambs with early coat development.
Asunto(s)
Estudios de Asociación Genética , Folículo Piloso/metabolismo , Animales , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 7 de la Matriz/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , OvinosRESUMEN
RT-PCR was used to study the temporal and spatial pattern of Yes-associated protein 1 (YAP1) and myosin heavy chain (MyHC) expression in four different skeletal muscles (i.e., longissimus dorsi muscle, soleus muscle, gastrocnemius muscle, and extensor digitorum longus) and three growth stages (i.e., 2 days old, 2 and 6 months old) of Hu Sheep. The results showed that YAP1 was differentially expressed in skeletal muscles of sheep, that expression increased gradually with age, and that there were high levels of expression in the gastrocnemius muscle and lower levels in the longissimus dorsi muscle. MyHCI was expressed at high levels in the soleus muscle and at lower levels in the longissimus dorsi muscle. In contrast, MyHCIIA and MyHCIIX were expressed at high levels in the extensor digitorum longus and at lower levels in the soleus muscle. The expression of MyHCI and MyHCIIA decreased with increasing age while that of MyHCIIX increased. YAP1 expression was negatively correlated with MyHCII (P < 0.01) and positively correlated with MyHCIIX (P < 0.01) across all growth stages and skeletal muscle types studied. We speculate that after birth, the thicker muscle fiber diameter is associated with the high expression of MyHCIIX. Therefore, we conclude that YAP1 expression affects sheep muscle fiber development after birth and provides important genetic information for the selection candidate genes for sheep muscle growth.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Cadenas Pesadas de Miosina/metabolismo , Ovinos/genética , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Regulación del Desarrollo de la Expresión Génica , Músculo Esquelético/crecimiento & desarrollo , Músculo Esquelético/metabolismo , Cadenas Pesadas de Miosina/genética , Especificidad de Órganos , Ovinos/crecimiento & desarrolloRESUMEN
The aim of the current study was to investigate the effects of Yes-associated protein 1 (YAP1) gene expression after birth on the development of muscle and the relationship between YAP1 and myostatin (MSTN) and myogenin (MyoG). Reverse transcription polymerase chain reaction was used to analyze the trends in YAP1, MSTN, and MyoG temporal and spatial expression levels in various skeletal muscles (i.e., longissimus dorsi muscle, soleus muscle, gastrocnemius muscle, and extensor digitorum longus) and across 3 different growth stages (i.e., 2 days old, 2 and 6 months old) of Hu Sheep. The results showed that YAP1 expression was significantly different in the skeletal muscles of sheep; the expression level gradually increased with age; it was highly expressed in the gastrocnemius muscle and minimally expressed in the longissimus dorsi muscle. MSTN, a negative regulator of skeletal muscle development, was minimally expressed in the soleus muscle and might be related to the enlargement of muscle fiber diameter. MyoG, an important factor in regulating skeletal muscle development, was minimally expressed in the longissimus dorsi muscle and extensor digitorum longus, and highly expressed in the gastrocnemius and soleus muscles; it might inhibit the enlargement of muscle fiber diameter after birth. YAP1 expression was significantly (P < 0.05) or extremely significantly (P < 0.01) and positively correlated with MSTN and MyoG at 2 days old, 2 and 6 months old. YAP1 expression was related to muscle fiber development after birth and might be a candidate gene for the regulation of muscle growth.
Asunto(s)
Regulación del Desarrollo de la Expresión Génica , Miogenina/genética , Miostatina/genética , Ovinos/genética , Animales , Animales Recién Nacidos , Músculo Esquelético/crecimiento & desarrollo , Músculo Esquelético/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ovinos/crecimiento & desarrollo , Factores de TiempoRESUMEN
The aim of the present study was to detect delta-like 1 ho-molog (DLK1) and insulin-like growth factor-I (IGF-I) gene expression in the longissimus dorsi of Hu sheep at different growth stages and study the association between these genes and meat quality. The diameter and density of muscle fibers and tenderness of the longissimus dorsi were measured. Growth stage, but not sex, significantly affected DLK1 and IGF-I expression. DLK1 and IGF-I expression in the sheep longissimus dorsi gradually increased with growth, but also decreased during some periods. These results suggest that different growth stages significantly affect DLK1 and IGF-I gene expression in sheep muscle tissue. The ex-pression of DLK1 and IGF-I genes were positively and significantly (P < 0.01) correlated with muscle fiber diameter and muscle fiber shear stress, and negatively and significantly (P < 0.01) correlated with muscle fiber density. Muscle fiber diameter was positively and significantly (P < 0.01) correlated with muscle fiber shear stress, and negatively and significantly (P < 0.01) correlated with muscle fiber density. In addition, DLK-1 expression was significantly (P < 0.01) and positively correlated with IGF-I expression.
Asunto(s)
Factor I del Crecimiento Similar a la Insulina/biosíntesis , Péptidos y Proteínas de Señalización Intercelular/biosíntesis , Carne , Proteínas de la Membrana/biosíntesis , Fibras Musculares de Contracción Lenta/metabolismo , Oveja Doméstica/genética , Animales , Expresión Génica , Factor I del Crecimiento Similar a la Insulina/genética , Músculo Esquelético/metabolismo , Oveja Doméstica/crecimiento & desarrolloRESUMEN
In the present study, real time-polymerase chain reaction was applied to analyze the expression of IGF-I and MyoG genes in Hu sheep longissimus dorsi at different growth stages and their association with meat traits. Expression of the IGF-I gene in Hu sheep differed significantly between males and females at the two day-old (0.01 < P < 0.05), one-month old (0.01 < P < 0.05), and three month-old (P < 0.01) stages. IGF-I gene expression in male longissimus muscles was higher than that of females at all growth stages, except for the three month-old stage. There was no significant difference (P > 0.05) between males and females at any growth stage in expression of the MyoG gene. MyoG gene expression in male longissimus muscles tended to be higher than that of females at all growth stages, except for the six month-old stage. IGF-I gene expression was significantly and positively correlated with live weight (P < 0.01) and carcass weight (0.01< P < 0.05), and was non-significantly positively correlated with net meat weight (P > 0.05). In contrast, MyoG gene expression was non-significantly and positively correlated with live weight, carcass, and net meat weight (P > 0.05). Carcass traits showed highly significant positive correlations (P < 0.01). Furthermore, expressions of IGF-I and MyoG genes showed highly significant positive correlations (P < 0.01). We conclude that the expressions of IGF-I and MyoG genes are significantly and positively correlated with early muscle traits of Hu sheep.