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With the exception of the domestic cat, all felid species (Felidae) are currently threatened with extinction in their natural habitat. To develop effective and optimal wild cat conservation programmes with assisted reproductive technology (ART) it is necessary to combine advances from different disciplines of science, starting from the biology of the species, through research into the population and habitat, assisted reproductive technologies, establishment of gene banks, developing bioinformatic systems, and ending with biodiversity and endangered species management. In the last few years knowledge of felid reproduction has expanded considerably thanks to comparative studies utilising the domestic cat as a research model for endangered wild cats. Basic reproductive techniques utilised in both domestic cat breeding and rescuing wild felid populations that are threatened with extinction include semen collection and cryopreservation, artificial insemination, oocyte collection, in vitro maturation, in vitro fertilisation, somatic cloning, and embryo transfer. The main directions in which assisted reproductive technologies are being developed in wild cat conservation implementations and the contribution of Polish research centres in advancing these methods are presented.

Simple Summary: This study was conducted with the aim of determining the morphological similarities and developmental potential of oocytes obtained from adult and prepubertal domestic cats (Felis catus) and wild cats. The results of our research showed that ovaries obtained from prepubertal felids may be a rich source of good quality oocytes that are competent for in vitro maturation and able to reach blastocyst stage after in vitro fertilization. The results are important in the context of the possibility of using oocytes from prepubertal felids threatened with extinction in conservation programs based on assisted reproductive techniques (ART). The aim of the study was to compare the morphology and developmental potential of oocytes obtained from adult and prepubertal domestic cats (Felis catus) and wild cats (Lynx lynx, Leptailurus serval, Felis manul, Panthera tigris altaica). The average number of oocytes obtained from an adult domestic cat was 23 ± 11, which was significantly lower than from kittens (43 ± 29). A similar number of oocytes was derived from adult Pallas's cats (28 ± 8), and serval (30). The lowest number of oocytes was collected from the lynx (5 ± 3). No oocytes were obtained from newborn Amur tiger while in the case of older domestic and Pallas's cat and lynx kittens (1–3 months) 43, 48 and 41 oocytes were collected, respectively. Significant differences (p < 0.001) were observed between the number of oocytes with dark cytoplasm from adult and prepubertal animals of all analyzed species. The diameter of oocytes from adult and prepubertal animals was similar in all species, and was on average 161 ± 4 µm for oocytes with dark cytoplasm and 150 ± 18 µm for oocytes with light cytoplasm. In all species, oocytes with light cytoplasm were significantly smaller (p < 0.05) than dark ones, and their population was more diverse. Results of in vitro maturation of the domestic and wild cat′s oocytes obtained from adult and prepubertal females were similar (47–52%). The cleavage rate after in vitro fertilization (IVF) was lower for prepubertal than adult domestic cats (42 vs. 51%; p < 0.05%). Moreover, we observed differences in the quantity (28 vs. 39%; p < 0.05) and quality of blastocysts and even greater problems with hatching blastocysts from prepubertal kittens (8 vs. 19%; p < 0.001). More blastomeres were detected in blastocysts of adult cats. They also demonstrated significantly higher number of inner cell mass (ICM) (p < 0.001) and higher number of trophoblast cells (TE) (p < 0.05). [ABSTRACT FROM AUTHOR]