Kim Y S, Bobbili N K, Paek K S, Jin H J
Department of Human Nutrition, Food and Animal Sciences, University of Hawaii at Manoa, Honolulu 96822, USA.
Poult Sci. 2006 Jun;85(6):1062-71. doi: 10.1093/ps/85.6.1062.
Myostatin, a member of the transforming growth factor-beta (TGF-beta) superfamily, is a potent negative regulator of skeletal muscle growth. The objective of this study was to produce a monoclonal anti-myostatin antibody and to examine the effects of in ovo administration of the antibody on posthatch broiler growth and muscle mass. The mature form of myostatin was expressed in Escherichia coli and used as an immunogen in producing a monoclonal antibody against myostatin. One hybridoma clone (mAb-c134) that showed the strongest affinity to the immunogen in Western blot analysis was used in producing a large quantity of monoclonal anti-myostatin antibody. In Western blot analysis, this antibody showed a strong binding affinity to commercially available mature myostatin and demonstrated a certain level of cross-reactivity with recombinant human BMP2 but not with recombinant human TGF-beta3 or porcine TGF-beta1. Competitive ELISA demonstrated binding of the antibody to the native form of mature myostatin in solution. To examine the effects of in ovo administration of the mAb-c134 antibody, eggs were injected once with 40 microg of mAb-c134 in 50 mL of PBS either into the albumen or yolk on d 3 of incubation. Controls received no injection. After hatching, chicks were raised for 35 d. Broilers from eggs that had the antibody injected into the yolk had significantly heavier body (4.2%) and muscle (5.5%) mass than the controls in both male and female birds. In contrast, no significant effects on body and muscle mass were observed when the mAb-c134 antibody was injected into the albumen. The results of this study suggest that immunoneutralization of myostatin during embryonic development is a potential means to improve growth potential of broilers.
肌肉生长抑制素是转化生长因子-β（TGF-β）超家族的成员之一，是骨骼肌生长的强效负调节因子。本研究的目的是制备一种抗肌肉生长抑制素单克隆抗体，并研究在鸡胚中注射该抗体对出壳后肉鸡生长和肌肉质量的影响。肌肉生长抑制素的成熟形式在大肠杆菌中表达，并用作免疫原以制备抗肌肉生长抑制素单克隆抗体。在蛋白质印迹分析中，对免疫原显示出最强亲和力的一个杂交瘤克隆（mAb-c134）被用于大量生产抗肌肉生长抑制素单克隆抗体。在蛋白质印迹分析中，该抗体对市售的成熟肌肉生长抑制素显示出强结合亲和力，并与重组人骨形态发生蛋白2（BMP2）表现出一定程度的交叉反应，但与重组人TGF-β3或猪TGF-β1无交叉反应。竞争性酶联免疫吸附测定（ELISA）表明该抗体可与溶液中成熟肌肉生长抑制素的天然形式结合。为了研究在鸡胚中注射mAb-c134抗体的效果，在孵化第3天，将50 μL PBS中含40 μg mAb-c134的溶液一次性注射到鸡蛋的蛋白或蛋黄中。对照组不进行注射。出壳后，将雏鸡饲养35天。在雄性和雌性雏鸡中，抗体注射到蛋黄中的鸡蛋孵出的肉鸡，其体重（重4.2%）和肌肉质量（重5.5%）均显著高于对照组。相比之下，当将mAb-c134抗体注射到蛋白中时，未观察到对体重和肌肉质量的显著影响。本研究结果表明，在胚胎发育过程中对肌肉生长抑制素进行免疫中和是提高肉鸡生长潜力的一种潜在手段。
