Fayrer-Hosken R A, Bertschinger H J, Kirkpatrick J F, Grobler D, Lamberski N, Honneyman G, Ulrich T
Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens 30602-7385, USA.
Theriogenology. 1999 Oct 1;52(5):835-46. doi: 10.1016/S0093-691X(99)00176-4.
Immunocontraception has been successful in controlling free-roaming equids; however, what is the potential for the immunocontraceptive control of the African elephant (Loxodonta africana)? The porcine zona pellucida (pZP) glycoproteins share antigenic domains with the African elephant zona pellucida (elZP) glycoproteins, and anti-zona pellucida serum antibodies have been successfully stimulated. To determine the cross-reactivity of the pZP and elZP, immunocytochemistry was evaluated by light and electron microscopy. Specifically, the binding of polyclonal antibodies against total heat-solubilized-porcine zona pellucida to fixed elephant ovary sections was evaluated. The elZP of primary, secondary and tertiary follicles was recognized by the rabbit-anti-pZP serum, but there was no apparent recognition of the primordial follicles. The ability of anti-pZP antibodies to recognize the elZP demonstrates that there is molecular homology between the pZP and elZP glycoproteins. This homology makes the African elephant a candidate for pZP immunocontraception. Three captive elephants were vaccinated with 400 micrograms pZP with a synthetic trehalose dicorynomycolate (S-TDCM) adjuvant. The elephants received 2 boosters of 600 micrograms pZP at 4 wk and 10 m.o. after the primary vaccination. The vaccinated female elephants developed significant (P < 0.05) titers to pZP over prevaccination levels. These levels persisted for 12 to 14 m.o. after the third vaccination. This preliminary evidence shows that the female elephant can develop significant serum antibody levels to pZP. These levels of antibodies are comparable to those required in horses for successful immunocontraception. Thus, porcine zona pellucida immunocontraception might be used to control elephant populations.
免疫避孕在控制自由放养的马科动物方面已取得成功；然而，对非洲象（Loxodonta africana）进行免疫避孕控制的潜力如何呢？猪透明带（pZP）糖蛋白与非洲象透明带（elZP）糖蛋白具有共同的抗原结构域，并且已成功刺激产生了抗透明带血清抗体。为了确定pZP和elZP的交叉反应性，通过光学显微镜和电子显微镜对免疫细胞化学进行了评估。具体而言，评估了抗总热溶性猪透明带的多克隆抗体与固定的大象卵巢切片的结合情况。初级、次级和三级卵泡的elZP能被兔抗pZP血清识别，但原始卵泡未被明显识别。抗pZP抗体识别elZP的能力表明pZP和elZP糖蛋白之间存在分子同源性。这种同源性使非洲象成为pZP免疫避孕的候选对象。三只圈养大象用400微克pZP与合成海藻糖二硬脂酸酯（S - TDCM）佐剂进行了疫苗接种。这些大象在初次接种后4周和10个月时接受了两次600微克pZP的加强接种。接种疫苗的雌性大象针对pZP产生的抗体效价比接种前水平显著升高（P < 0.05）。这些水平在第三次接种后持续了12至14个月。这一初步证据表明雌性大象能够产生针对pZP的显著血清抗体水平。这些抗体水平与马匹成功进行免疫避孕所需的水平相当。因此，猪透明带免疫避孕可能可用于控制大象种群。
