Study on structure development characteristics of German Merino sheep fetal skeletal muscle tissue
[Objective] The purpose of this study is to explore the formation and development pattern of muscle fiber and reveal the developmental characteristics of skeletal muscle tissue in fetal period of German Merino sheep.[Method] Three times of D75,D105 and D135 during pregnancy were selected.The body size of German Merino fetal sheep was measured.Longissimus tissue from fetal sheep was collected and subjected to tissue sections and HE staining to count for the fiber number,diameter and density at different developmental stages of feta1 muscle tissue.Fiber type was determined using immunohistochemistry to clarify the number of fast/slow muscle fiber type in dfferent stages of development.[Result] At the period from D75 to D135 of pregnant,the increase of fetal weight was nearly 17 times,the body length and height is nearly 1.5 times.The numbers of muscle fibers in unit area gradually increased to D105 while reach the highest value,and the overall trend first climbed up and then declined.The growth rate of diameter of muscle fibers from D75 to D105 was relatively smooth,but that of D105-D135 obviously increased.In middle stage,the slow muscle (type Ⅰ muscle fiber) was the main type,and the latter was mainly composed of fast muscle (type Ⅱ muscle fiber).[Conclusion] The number of German Merino sheep fetal muscle fiber reached peak at D105,and the number of muscle fiber is almost constant.We found that the pregnant time of 105 days was a critical time window with fiber developmental transformation from muscle hyperplasia to muscle hypertrophy,and made clear the slow muscle (type Ⅰ muscle fiber) was the main type during middle stage,and the latter stage was mainly composed of fast muscle (type Ⅱ muscle fiber).
German Merinofetusskeletal musclehistological structure
NETL
NSTL
万方数据
维普
