双拷贝抑制素基因免疫对肉牛卵泡和黄体的影响

 【目的】探讨不同剂量的双拷贝抑制素pcISI基因免疫对肉牛生殖能力的影响。【方法】将58头同期发情肉牛随机分为6组, 每组肉牛分别注射0.75（T1）、1.5（T2）、2.25（T3）、3.0 mg/头（T4）pcISI质粒、3.0 mg/头 pcMV-S空质粒（C1）和3 mL/头 生理盐水（Ｃ2）,初次免疫21d后进行加强免疫,以探讨抑制素pcISI基因疫苗对肉牛卵泡和黄体发育的影响。【结果】4个剂量组的大卵泡数均高于对照组,除了T1外,其它3个剂量组均与对照组差异显著（P＜0.05）;T3和T4的中卵泡数均高于对照组,且差异显著（P＜0.05）;T3和T4的小卵泡数均高于对照组,且差异显著（P＜0.05）。无论左侧还是右侧,各剂量组成熟卵泡直径均高于对照组,除了T1外,其它3组两侧成熟卵泡均与对照组差异显著（P＜0.05）。无论左侧还是右侧,4个剂量组黄体直径均高于对照组,且均与对照组差异显著（P＜0.05）;T3黄体最大,T1最小,且T3与T1差异显著（P＜0.05）。加强免疫后10 d（BM10）抑制素抗体与成熟卵泡大小相关显著（r＝0.629,P＜0.05）,与黄体大小相关极显著（r＝0.651,P＜0.01）。【结论】双拷贝抑制素pcISI基因免疫可促进肉牛卵泡和黄体发育,2.25mg为最佳免疫剂量,抑制素抗体水平与卵泡和黄体发育有一定的相关性。

Effect of DNA Vaccine pcISI Harboring Two Copies of Inhibin on Follicle and Corpus Luteum of Beef Cattle

[Objective] The effect of four different dosages of inhibin gene expressing plasmid on the reproductive capacity of the beef cattle was studied. [Method] Fifty eight synchronized beef cattle were randomly assigned to four dosage groups (T_1, T_2, T_3, or T_4 , immunized with 0.75, 1.5, 2.25, or 3.0mg of DNA vaccine pCISI harboring two copies of INHal-32, respectively) and two control groups (C_1 ,which was injected with 3.0mg pcMV-S plasmid per cattle and C_2 , which was injected with physiological saline 3 mL per cattle) to investigate the effect of inhibin gene immunization on development of follicle and corpus luteum, and the booster immunization was given to the cattle on day 21 after the primary immunization. [Result] Animals in the four dosage groups had a greater number of large follicles (≥10 mm) than those in group C, and the number of large follicles was significantly larger than those in group C (P<0.05). Compared to the control group, the number of medium and small follicles in T_3 was much larger (P< 0.05), the same as T_4. Moreover, luteum corpuses on bilateral ovaries of beef cattle in the four-dosage inhibin gene vaccine-immunized groups were significantly larger than those in group C (P<0.05). Among the four dosage groups, the largest luteum corpus was in T_3, the smallest was in T_1, there was a significant difference between T_3 and T_1. Besides, on day 10 after booster immunization, there was a difference in correlation coefficient between the content of inhibin antibody and size of the mature follicles (r = 0.629, P<0.05), and the content of inhibin antibody and the size of the corpus lutuem was significantly different (r = 0.651, P<0.01). [Conclusion] These findings demonstrate that inhibin gene vaccine pcISI is able to stimulate development of follicle and corpus luteum. Dosage of 2.25 mg is the best dosage in the study.