Reprocon, Reproduction for Conservation Research Group, Brazil; Faculty of Veterinary Medicine and Husbandry, University of Sao Paulo, São Paulo, SP, Brazil.
Reprocon, Reproduction for Conservation Research Group, Brazil; Faculty of Veterinary Medicine and Husbandry, University of Sao Paulo, São Paulo, SP, Brazil; NEX - No Extinction Scientific Breeding Center, Corumbá de Goiás, GO, Brazil.
Theriogenology. 2020 Apr 15;147:57-61. doi: 10.1016/j.theriogenology.2020.02.026. Epub 2020 Feb 17.
Threatened of extinction in Brazil, the jaguar is the largest predator in Latin America, playing an important role in the ecosystem where it is inserted. Despite of some important studies in this species, its reproductive physiology needs to be better understood for the development of more effective reproductive biotechnologies. One well studied biological aspect is the occurrence of ovulation following stimulation of the vaginal floor during copulation. This mechanical stimulation is responsible for the induction of ovulation in domestic and wild cats. Thus, the objective of the present study was to evaluate whether ovulation in captive jaguars can be induced by the above-mentioned mechanical stimulation but also by other forms of sensory stimulation. Nine jaguar (Panthera onca) females and six males were divided into three groups: Group 1 (four females), in which the females were close to the males, but with no possibility of copulation; Group 2 (three females), in which the females were in the same enclosure as the males, thereby being able to copulate; and Group 3 (two females), in which the females were completely isolated from any male of the species. Follicular growth was stimulated by administration of 800 IU of eCG, conducted three or five days before LOPU. In order to have certainty about the occurrence of ovulation, the ovaries were assessed by laparoscopy allowing the visualization of ovarian structures including follicles, recent ovulations, corpora hemorrhagica (CH) and corpora lutea (CL). Multiple CH were observed in the 2 females housed with males, as well as the two females kept in proximity of males, i.e. only visual contact (Group 1). None of the females in complete isolation from males showed CH or ovulation spots (Group 3). In summary, the seven females in contact or near proximity with males had multiple ovulations, regardless of copulation or not. Based on this evidence, we have established that jaguars are capable of two forms of induced ovulation: 1) the "mechanical" coitus-induced form that is traditional and thoroughly described for felines; 2) a "sensorial" form in which the nearby presence of a male can induce ovulation through the visual, olfactory and/or auditive senses. Further research is required for establishing the mechanisms and chemical mediators of sensorial stimulation. In addition, and consistent with expected results, we confirmed that females that received the same stimulation are incapable of ovulating when not exposed to any form of stimulation by males.
在巴西，美洲虎面临灭绝威胁，是拉丁美洲最大的掠食者，在其栖息的生态系统中发挥着重要作用。尽管对该物种进行了一些重要的研究，但为了开发更有效的生殖生物技术，仍需要更好地了解其生殖生理学。一个研究得很好的生物学方面是阴道底部在交配时受到刺激后发生排卵。这种机械刺激负责诱导家猫和野生猫排卵。因此，本研究的目的是评估圈养美洲虎的排卵是否可以通过上述机械刺激，也可以通过其他形式的感觉刺激来诱导。九只雌性美洲虎（Panthera onca）和六只雄性美洲虎被分为三组：第 1 组（四只雌性），雌性接近雄性，但不能交配；第 2 组（三只雌性），雌性与雄性在同一个围栏中，从而能够交配；第 3 组（两只雌性），雌性完全与任何雄性隔离开来。使用 800IU 的 eCG 对卵泡生长进行刺激，在 LOPU 前三天或五天进行。为了确定排卵的发生，通过腹腔镜检查评估卵巢，使卵巢结构包括卵泡、最近的排卵、黄体出血（CH）和黄体（CL）可视化。在与雄性一起饲养的 2 只雌性以及与雄性近距离接触的 2 只雌性中观察到多个 CH（第 1 组）。完全与雄性隔离开来的雌性均未显示 CH 或排卵点（第 3 组）。总之，与雄性接触或近距离接触的七只雌性有多次排卵，无论是否有交配。基于这些证据，我们已经确定美洲虎能够进行两种形式的诱导排卵：1）“机械”交配诱导形式，这是传统的，并且对猫科动物进行了彻底的描述；2）“感觉”形式，即雄性的近距离存在可以通过视觉、嗅觉和/或听觉来诱导排卵。需要进一步研究以确定感觉刺激的机制和化学介质。此外，与预期结果一致，我们确认在未受到雄性任何形式刺激的情况下，接受相同刺激的雌性无法排卵。
