胎儿期与成年期蒙古马骨骼肌肌纤维类型转化研究

为探索影响蒙古马胎儿期和成年期肌纤维类型差异机理.本研究选取3匹4月龄胎儿(两母一公)与3匹5岁健康成年母马身体4块分布全身、具有代表性的肌肉组织(长臂三头肌、夹肌、背最长肌、臀中肌)作为一个整体.胎儿期蒙古马肌纤维和成年期蒙古马肌纤维因存在差异各做为一组,试验进行3个生物学重复.首先对蒙古马骨骼肌肌肉样品进行免疫组化...

Study on Muscle Fiber Type Transformation of Mongolian Horse during Fetal and Adult Period

The study aimed to explore the mechanism of muscle fiber type difference between fetal and adult Mongolian horses.In this study,three 4-month-old fetuses(two females and one male)and three 5-year-old healthy adult female horses were selected as a whole with 4 body-distributed and representative muscle tissues(triceps brachii,splenius,longissimus dorsi and gluteus medius).Fetal Mongolian horse muscle fiber was one group,and adult Mongolian horse muscle fiber was one group,the experiment carried out 3 biological repetitions.Firstly,the skeletal muscle samples of Mongolian horses were observed by immunohistochemical staining.Then,the skeletal muscle samples were subjected to RNA-seq to construct the mRNA expression profiles of skeletal muscle fibers in different periods of fetal and adult Mongolian horses.Differentially expressed genes were screened for GO and KEGG functional enrichment analysis.Histological results showed that the proportion of fast muscle fibers in the fetal period was significantly higher than that in the adult period.RNA-seq was used to screen candidate genes that might affect the transformation related to muscle fiber types.The gene expression profiles related to muscle fiber types in fetal and adult Mongolian horses were compared.A total of 250 differentially expressed genes were screened out.There were 27 up-regulated genes in adulthood,including TNNT1,MYOZ2 and ATP2A2,and 17 up-regulated genes in the fetal period,including MYL1,TNNT3 and ENO3.ATP2A2 and TNNT1 were mainly related to fast and slow muscle fiber type transformation,and these differentially expressed genes were also closely related to skeletal muscle growth and development.The results showed that the proportion of fast muscle fibers in fetal Mongolian horses was significantly higher than that in adult Mongolian horses.ATP2A2,MYOZ2 were mainly expressed in muscle fibers of adult Mongolian horse,ENO3,TNNI2 were mainly expressed in muscle fibers of fetal Mongolian horse.Calcium and AMPK signaling pathways are related to muscle fiber type conversion.The results of this experiment are of great significance to the study of Mongolian horse muscle fiber type transformation.