Velleman S G, Nestor K E
Department of Animal Sciences, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio 44691, USA.
Poult Sci. 2003 Sep;82(9):1373-7. doi: 10.1093/ps/82.9.1373.
The temporal and spatial localization of the heavy chain fast form of myosin was studied during turkey pectoralis major muscle development in a randombred control line (RBC2), a subline (F) of RBC2 selected only for increased 16-wk BW, a commercial sire line (B), and reciprocal crosses of the F and B lines. Pectoralis major muscle samples were obtained from three females and three males from each group in a manner to avoid contraction. After fixing and sectioning, the muscle samples were stained with a monoclonal antibody to determine the temporal and spatial localization of the heavy chain fast form of myosin. The percentage of muscle fibers at 25 d of incubation and 1 wk posthatch expressing the fast form of myosin heavy chain was calculated. The average percentage of muscle fibers expressing the fast form of myosin heavy chain for all genetic lines combined at embryonic d 25 for males was 76.1 and for females 66.6, whereas at 1 wk posthatch the average percentage for males was 24.2 and 36.1 for females. No interaction of sex and genetic group was noted at either age. At 25 d of embryonic development and at 1 wk of age, additive and nonadditive genetic effects were important in the inheritance of the fast form of myosin heavy chain. Heterosis was negative at both ages but significant at 1 wk of age. By 4 wk posthatch, all the muscle fibers in each genetic group were expressing the myosin heavy chain fast form, and no sex differences were observed. At 16 wk posthatch muscle fiber fragmentation was noted in the samples having reduced endomysial spacing. In the fragmenting muscle fiber areas, expression of the heavy chain fast form of myosin was observed. These muscle fiber changes were predominant in the growth selected F-line suggesting that growth selection may be associated with muscle damage.
在一个随机交配对照系（RBC2）、仅因16周龄体重增加而选择的RBC2亚系（F）、一个商业父系（B）以及F系和B系的正反交组合中，研究了火鸡胸大肌发育过程中肌球蛋白重链快速形式的时空定位。从每组的三只雌性和三只雄性中获取胸大肌样本，获取方式避免肌肉收缩。固定和切片后，用单克隆抗体对肌肉样本进行染色，以确定肌球蛋白重链快速形式的时空定位。计算孵化25天和出壳后1周表达肌球蛋白重链快速形式的肌纤维百分比。在胚胎第25天，所有遗传系组合的雄性表达肌球蛋白重链快速形式的肌纤维平均百分比为76.1，雌性为66.6；而出壳后1周，雄性的平均百分比为24.2，雌性为36.1。在两个年龄段均未发现性别与遗传组之间的相互作用。在胚胎发育第25天和1周龄时，加性和非加性遗传效应在肌球蛋白重链快速形式的遗传中起重要作用。两个年龄段的杂种优势均为负，但在1周龄时显著。到出壳后4周，每个遗传组的所有肌纤维均表达肌球蛋白重链快速形式，未观察到性别差异。在出壳后16周，在内膜间距减小的样本中发现了肌纤维碎片化。在肌纤维碎片化区域，观察到了肌球蛋白重链快速形式的表达。这些肌纤维变化在生长选择的F系中占主导地位，表明生长选择可能与肌肉损伤有关。
