鳜慢肌胚后发育与生长特征

鱼类快肌和慢肌分别占据骨骼肌的不同位置,表现不同的生长发育特征。为了解鳜(Sinipercachuatsi)慢肌纤维的胚后发育特征,本研究通过制作孵化后1～33日龄鳜个体的石蜡切片,采用慢肌特异抗体的免疫组织化学染色,观察了背鳍起点处躯干横切面慢肌的发育变化特征,并利用图像分析软件统计慢肌纤维的数目和面积。结果表明,孵化后鳜仔鱼慢肌位于水平肌隔附近,呈楔形,向背、腹两侧生长。孵化后1～9日龄为单层肌纤维,11日龄发育为多层肌纤维,19日龄覆盖侧线附近,33日龄延伸至背侧第2背肌节、腹侧腹部肌肉2/3处,并在水平肌隔和侧线处分别形成两个肌群。位于骨骼肌最外层的扁平状表层细胞,可能为慢肌增生生长的主要来源。躯干单侧慢肌肌纤维数目由孵化后6个增加至315个,总面积从13.18μm2增加到7 839.58μm2,孵化后13日龄的增生生长占优势,其他发育阶段,肥大生长一直占主导优势。

Postembryonic Development and Growth of Slow Muscle Fibers of Mandarin Fish (Siniperca chuatsi)

In most fish,slow and fast muscle fibers occupy distinct regions in the axial muscle and display different growing characteristics.To fully understand the postembryonic development feature of slow muscle fibers of Mandarin Fish(Siniperca chuatsi),we made paraffin section at the base point of the dorsal fin on individuals at age 1 to 33 days and dyed paraffin section by immunohistochemistry method.We also identified the number of slow muscle fibers and measured their area by using image analysis software.The results showed that slow muscle fibers located near the horizontal septum after hatching with a wedge shape,later they extended to the dorsal and ventral.At age 1 to 9 days,the slow muscle fibers were monolayer,then they became multilayers at age 11 days.Slow muscle fibers covered across the lateral line at age 19 days,then extended to the second dorsal myotome and down to 2/3 of ventral myotome and became into two muscle fiber sections at 33 days,which were located at the horizontal septum and lateral line,respectively.The superficial,spindle cells of skeletal muscle may were the main source of slow muscle fibres hyperplasia growth.The total numbers of slow muscle fibers increased from 6 to 315 after hatching,and the total fiber area increased from 13.18 μm2 to 7 839.58 μm2.Hyperplasia growth of muscle fiber was dominant at age of 13 days,where as hypertrophic growth was dominant at the other ages.