Noninvasive monitoring of ovarian function in jaguars (Panthera onca) via enzyme-linked immunosorbent assay and characterization of the fecal steroid metabolites through high performance liquid chromatography

• Grant number: 13/12757-9
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2013
• End date: February 29, 2016
• Field of knowledge: Biological Sciences - Physiology
• Principal Investigator: Valeria Amorim Conforti
• Grantee: Valeria Amorim Conforti
• Host Institution: Pró-Reitoria Adjunta de Pesquisa e Pós-Graduação. Universidade de Franca (UNIFRAN). Franca , SP, Brazil
• Associated researchers: Márcio Luís Andrade e Silva ; Ronaldo Gonçalves Morato

Abstract

The application of Assisted Reproduction Technologies (ART) to endangered species has gained increasing attention among researchers and conservationists globally. Successful application of ART can contribute to maintain genetically viable animal populations but it requires a deep knowledge of the species' reproductive physiology. Understanding the ovarian function in a species is crucial in the development of efficient protocols for ovarian stimulation as part of artificial insemination protocols. Female cats are traditionally referred to as induced ovulators; however, it has been shown that many cat species can ovulate spontaneously as well. Thus, it is necessary to know whether or not the females of a particular cat species can ovulate spontaneously given that spontaneous, post-ovulatory increases in progesterone concentrations would impair the ovarian stimulation desired in artificial insemination protocols. The jaguar (Panthera onca) - one of the most important species of the native Brazilian fauna, is among the cat species whose ovarian function and possibility of spontaneous ovulation have yet to be investigated. However, before using noninvasive methods to investigate the possibility of spontaneous ovulation in a cat species, it is important to stablish a protocol for assessing fecal progesterone metabolite concentrations that effectively detects the most relevant fecal progestins in the species. Commercial enzyme-linked immunosorbent assay kits are designed to detect the original hormone, in this case, progesterone, but they do not necessarily detect fecal progestins with the same efficacy. Physiological increases in fecal progestins have been observed in apparently anovulatory estrous cycles in jaguars, but whether these progestins are from follicular or luteal origin remains to be investigated. Therefore, the objectives of this study are: 1) to characterize the composition of steroid metabolites present in fecal samples from reproductively intact female jaguars via high performance liquid chromatography throughout the estrous cycle using progesterone and estradiol as reference; and 2) to monitor noninvasively the estrous cycle of these jaguars by assessing fecal estrogen and progesterone metabolite concentrations via enzyme-linked immunosorbent assay. Six captive female jaguars will be longitudinally monitored in terms of ovarian function during 4 consecutive months so that increases in fecal progestins will be detected, indicating spontaneous ovulation or follicular activity, depending on the phase of the estrous cycle during which they occur. The estrous cycle phase will be determined based on estrogenic concentrations. Results from this study will provide new information on the composition of fecal steroid metabolites and their origin in jaguars. (AU)