中文摘要：

家蚕多角体病毒表达系统在家蚕体内表达基因重组的草鱼生长激素（r-gGH），具有与天然草鱼生长激素（GH）相似的免疫原性和生物活性。为了节省基因工程研究中的下游工作（基因产物的分离和提纯），本研究将含有r-gGH的家蚕直接作为饵料源，冻干并磨碎后拌在饵料中投喂草鱼鱼种，通过养殖实验及生化测定分析对比r-gGH促进草鱼鱼种生长的剂量依存关系，筛选活性强的处理剂量和处理时间，期望为鱼类养殖生产提供一种较为经济、来源容易、方法简易而又切实可行的促进鱼种生长并且可以大规模应用的方式。实验结果表明，投喂含有r-gGH的家蚕，有相当一部分被鱼体消化道吸收，进入血液循环。投喂2h和6h后，草鱼鱼种的血清GH水平均显著高于对照组（投喂基本饲料）和投喂正常家蚕组；每天投喂和隔2天投喂，均使草鱼鱼种的血清GH水平显著升高，并对草鱼鱼种生长都有明显的促进作用。短期（3d）和长期（42d）投喂含有r-gGH的家蚕，无论是低剂量（10mg·g^-1饲料）还是高剂量（20mg·g^-1饲料），均极其显著地提高草鱼鱼种的血清GH水平；长期（42d）投喂亦对草鱼鱼种的生长有显著的促进作用，鱼体的相对体重增长率、相对体长增长率、食物转化率和肥满度显著增加。

英文摘要：

Recombinant silkworm （ Bombyx mori） nuclear polyhedrosis viruses were applied to express recombinant grass carp growth hormone （r-gGH）, which shows similar immunoactivity and bioactivity as natural grass carp growth hormone （GH）. To save lots of effort in the downstream work, especially to get rid of the complicated purification of r-gGH, the silkworms expressing r-gGH we used as a foodstuff additive with aims to stimulate growth of juvenile grass carp （ Ctenopharyngodon idellus ） and to optimize administration conditions for further economic and practical applications in large-scaled aquaculture. Silkworms expressing r-gGH were freeze-dried, ground into powder, mixed with basic foodstuff, and then orally administered to cultured juvenile grass carps in Zhongshan University, Guangzhou. The dietary delivery experiments proved that r-gGH can be absorbed into the circulation and to target organs to play its physiological roles. Short-term feeding of r-gGH silkworm-containing foodstuff （ r-gGH scf）, compared with feeding of normal silkworm-containing foodstuff or basic foodstuff, significantly elevated serum GH levels in juvenile fish at 2 h and 6 h post-feeding. Feeding everyday or every 3 days also increased fish serum GH levels, and remarkably improved fish growth. Applying different doses of r-gGH silkworms, 10 or 20 mg ·g^-1 diet, caused significant elevation of fish serum GH levels during short （3 days） and long （42 days） treatments. Long-term feeding （for 42 days） of r-gGH scf demonstrated remarkable stimulation on fish growth, with significant increases in relative size growth rate, relative length growth rate, food change efficiency and condition factor. In a word, our studies demonstrated that dietary delivery of r-gGH in r-gGH scf showed GH immunoactivity and bioactivity in cultured juvenile fish; and subsequently resulted in dose-dependent increase in fish serum GH level, and stimulation on fish growth. Our work suggests that oral administration of recombinant GH-contain