Reproduction management in female Lynx (Lynx lynx)
Lynxes undergo a non-cat like ovarian cycle. Before conducting the studies contained in this thesis, hardly anything of the cycle was fully understood. Concerning conservation aspects, it was important to understand how luteogenesis functions and if it could be manipulated artificially to increase t...
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| Other Authors: | , , , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
| Published: |
2017
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| Subjects: | |
| Online Access: | https://refubium.fu-berlin.de/handle/fub188/2307 https://doi.org/10.17169/refubium-6508 https://nbn-resolving.org/urn:nbn:de:kobv:188-fudissthesis000000104159-7 |
| Summary: | Lynxes undergo a non-cat like ovarian cycle. Before conducting the studies contained in this thesis, hardly anything of the cycle was fully understood. Concerning conservation aspects, it was important to understand how luteogenesis functions and if it could be manipulated artificially to increase the reproductive output. Therefore, results from examinations of Lynx from different latitudes, from captivity and the wild, and of two different species (Iberian and Eurasian Lynx) were gathered, using high resolution ultrasonography and serum hormone analysis. During our investigations we found out, that the persistent CL, unique to Lynx, are physiological and remain active over an extended period of more than two years. We established a new term for this period: the “prolonged di-oestrus”. These CL seem to undergo one of the longest known lifespan of luteal tissue in mammals. After ovulation, which can be spontaneous or induced in Lynx, the follicular tissue undergoes a typical felid transformation into luteal tissue. Contrarily, the CL do not undergo regression after parturition or pseudopregnancy, as they do in other felids and most mammals. They continue the secretion of P4 and E2, which we could proof to be of luteal origin. Interestingly, each time E2 starts to increase (which indicates the onset of a new follicular phase), P4 increases simultaneously. This might be a negative feedback mechanism to inhibit a second oestrus within the same season and maintain the monoestrus status of the Lynx. All Lynx within a geographical region give birth approximately within the same week. This phenomenon seems to be of low plasticity, which might hinder the Lynx in adapting fast enough to anthropogenic or climatic changes. Hence, it was important to discuss a variety of hormone protocols and if those were able to influence the Lynx’ cycle. Artificial luteolysis resulted in similar reactions to a natural functional regression before oestrus onset and parturition. Naturally, PGFM elevations were detected before oestrus onset ... |
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