Sperm cryopreservation in the Far‐Eastern wildcat (Prionailurus bengalensis euptilurus)

Abstract

The Far-Eastern wildcat (Prionailurus bengalensis euptilurus) is a rare and poorly investigated nondomestic felid species. An attempt of freezing and cryopreserving Far-Eastern wildcat spermatozoa in CaniPlus Freeze (CPF) medium is reported. Sperm was collected by electroejaculation from five adult Far-Eastern wildcat captive-born males. Epididymal spermatozoa from five adult randomly bred domestic cat males were used as a reference. The viability of frozen-thawed spermatozoa evaluated by double staining with SYBR Green I and PI followed by the subsequent confocal laser scanning microscopy (CLSM) was 38.2% ± 3.0% for the domestic cat and 38.0% ± 10.2% for the Far-Eastern wildcat. The motility of frozen-thawed spermatozoa was 30.8% ± 9.8% for the domestic cat and 33.7% ± 15.1% for the Far-Eastern wildcat. Sperm morphology was assessed by light microscopy. The total percentage of normal spermatozoa after freezing and thawing was 51.9 ± 5.9 for the domestic cat and 55.0% ± 6.4% for the Far-Eastern wildcat. Defects of flagella were the most frequently observed abnormalities in both species (32.2% ± 4.8% and 30.8% ± 4.4% of all reported anomalies for the domestic cat and Far-Eastern wildcat, respectively). Domestic cat epididymal and Far-Eastern ejaculatory spermatozoa fertilized in vitro-matured oocytes of the domestic cat (30.0% ± 5.5% and 35.5% ± 15.0%, respectively). Taken together, these results suggest that the freezing of Far-Eastern wildcat spermatozoa with CPF medium is a suitable method for Felidae cryopreservation.

IGF-I Medium Supplementation Improves Singly Cultured Cat Oocyte Maturation and Embryo Development In Vitro

“…Laboratory models are needed for wild species, as they allow us to develop the basis for techniques that later can be adapted to the special requirements of a target species if needed [48]. We already showed that techniques developed in the domestic cat can be successfully applied to wild cats [49][50][51]. Samples from wild cats are extremely rare and cannot be used for basic research.…”

Effects of slow freezing and vitrification on embryo development in domestic cat

“…Nuclei staining with subsequent cell number counting makes it possible to assess felid embryo development (Amstislavsky et al., 2018). Moreover, the percentage of nuclear fragmentation is taken as a measure of the nuclear integrity and embryo development (Amstislavsky et al., 2015; Brison & Schultz, 1997).…”

“…To perform these analyses after IVC, embryos were fixed in one mL of DPBS with 4% formaldehyde at pH 7.4-7.6. After fixation, embryos were stained with DAPI, as described earlier (Amstislavsky et al, 2015(Amstislavsky et al, , 2018. Slides with embryos were analysed under LSM 780 NLO AxioObserver Z1 (Carl Zeiss, Germany) with filters suitable for DAPI.…”

“…Cryopreservation of gametes and embryos combined with other reproductive technologies is an effective way to maintain genetic diversity for mammalian species (Comizzoli & Holt, 2014). Some felids are of great public concern (Cocchia et al., 2015), and domestic cat may be considered as a model species to apply Genome Resource Banking (GRB) to these wild felids (Amstislavsky et al., 2018; Amstislavsky, Lindeberg, & Luvoni, 2012). Felid oocytes and preimplantation embryos contain large amount of intracellular lipids (Amstislavsky, Mokrousova, Brusentsev, Okotrub, & Comizzoli, 2019; Apparicio et al., 2012).…”

Establishment of semen collection technique using electroejaculator and semen cryopreservation of Javan leopard (Panthera pardus melas Cuvier, 1809)

“…Studies on the reproductive biology of the Javan leopard have never been reported, unlike in several other wild cats, including the Indian [5], Arabian (P. pardus nimr) [6], and the Indochina (P. pardus delacouri) leopard [7]. Semen cryopreservation efforts in wild cats such as the jaguar (Panthera onca) [8], clouded leopard (Neofelis nebulosa) [9], Prionailurus bengalensis euptilurus [10], and the Sunda clouded leopard (Neofelis diardi) [11] have been reported. A sperm bank/genome bank is a vital step and effort for longterm wildlife conservation [12].…”