Theriogenology wild最新文献

Non-invasive techniques utilizing fecal samples to measure circulating steroid hormones have proven to effectively reflect the reproductive status of numerous species. Fecal progesterone metabolite (FPM) profiles have enhanced our understanding of the complicated reproductive strategies of many endangered species; however, this tool has been proven to not be optimal for pregnancy detection in the red panda (Ailurus fulgens). This study set out to investigate potential differences in FPM profiles (phases and lengths of hormone elevation) of seven female red pandas, both parturient and non-parturient, confirming FPM analysis is not a valuable indicator of pregnancy in this species. Secondly, examined whether a pregnancy related hormone, prostaglandin F2α and its metabolites (PGFM), can provide a reliable tool for confirming pregnancy in this species. Similarly, PGFM did not differentiate between parturient and non-parturient females until a significant peak the day of parturition (± 2 days). Interestingly, this is the first study to capture the PGFM surge associated with parturition, which may provide a tool for determining pregnancy in cases where live cubs were not observed.

Little is known about the reproductive biology of the Canada lynx; virtually no data are available describing seminal parameters in this species and sperm cryopreservation studies have not been performed. Our aims were to 1) evaluate effectiveness of two semen collection methods: urethral catheterization (UC) and electroejaculation (EEJ); 2) characterize basal seminal traits throughout the breeding season; 3) compare effectiveness of semen cryopreservation using TEST egg yolk (TEY) or soy lecithin-based (SOY) media; and, 4) evaluate the ability of preserved Canada lynx sperm to fertilize domestic cat in vitro matured oocytes by heterologous in vitro fertilization. Testicular volume averaged 4.5±1.0 cm³. A significant relationship was found between animal body weight and testes volume (P<0.02), as well as for testicular volume and sperm counts per ejaculate (P<0.01). Fecal testosterone concentrations and sperm production were correlated (P<0.01). Electroejaculation was more reliable than UC for sperm collection (8.8 and 1.5 × 10⁶ sperm, respectively; P<0.01). The percentage of sperm with normal morphology was greater in EEJ (29 ± 11 %) than in UC (18 ± 9 %) (P<0.05) samples and primary sperm structural abnormalities were more frequent in UC than EEJ samples (P<0.01). Overall, sperm quality was low in most males throughout the breeding season, but consistent with previous findings in the Lynx genus. Sperm production averaged 10.8 × 10⁶ sperm/ejaculate with 45 % motility; 29 % normal morphology and 69 % acrosome integrity. Motility and acrosome integrity post-thaw declined over time, but were similar between spermatozoa cryopreserved in TEY and SOY media (P > 0.05). Cleavage rates did not differ between TEY (29 ± 17 %) and SOY (27 ± 14 %) and mean numbers of sperm bound to the zona pellucida was similar (20 sperm, TEY vs. 18 sperm, SOY), indicating that both extenders equally preserved the function of Canada lynx sperm for semen banking purposes. Our findings provide zoos and population managers with valuable information about normative reproductive traits in this species, establishing comparative benchmarks for assessing the reproductive potential of specific males recommended for breeding.

The ghost bat (Macroderma gigas) is the largest microbat in Australia and occupies a large but contracting range. The ghost bat is listed as Vulnerable with a decreasing population trend by the IUCN Red List of Threatened Species. They occupy caves, disused mine adits and rock crevices as daytime roosts but distinguishing which are preferred as maternal roosts is challenging as sampling is difficult, and bats are easily disturbed while roosting. Identification of maternal roosts is a priority for conservation and management purposes, and therefore non-invasive hormone analysis was investigated as a potential tool for the future identification of the cave preferences of pregnant individuals. To validate fecal progesterone metabolite analysis techniques, fecal samples were collected from group housed female ghost bats at Perth Zoo between October and January, during the expected parturition period, over three years. Fecal samples were weighed (0.025 g), extracted with 2.5 ml of 80% methanol and analyzed for progesterone metabolite levels by enzyme-immunoassay. Significant elevations in fecal progesterone metabolite levels were detected in a subset of samples collected from co-housed females prior to parturition but not after, providing biological validation of the hormone analysis techniques. Over the three years, four pups were born with birth dates ranging from early November to late December. The mean fecal progesterone metabolite levels of non-pregnant females was significantly lower than those of pregnant females (206.5 ± 102.9 ng/g and 7003.6 ± 6078.0 ng/g respectively). These techniques can be used to monitor and evaluate the reproductive health of ghost bat populations over time and help identify factors influencing maternity roost fidelity. This data will provide valuable information for the conservation and management of the ghost bat and has the potential to be applied to other bat species.

Spermatozoa collected from the cauda epididymis of wild ruminants are more cryoresistant than ejaculated spermatozoa. Changes in the membrane location of aquaporins (AQPs) follow the osmotic changes that occur during freeze-thawing, and might influence the cryosurvival of spermatozoa depending on their source. This work reports the location of AQP3, AQP7 and AQP10 in the cauda epididymal and post-ejaculation spermatozoa of three wild mountain ungulate species (Iberian ibex, mouflon, and chamois), as determined by Western blotting (WB) and immunocytochemistry (ICC) using commercial rabbit polyclonal primary antibodies. WB confirmed the presence of all three AQPs in the spermatozoa of all the studied species, while ICC showed AQP3 to be mainly located in the sperm acrosome, mid-piece, principal piece, and end piece, both in cauda epididymal and ejaculated cells. The percentage of ejaculated spermatozoa showing AQP3 in the principal piece was higher in the ibex than in the chamois (P < 0.05), and higher in epididymal spermatozoa in the mouflon than in the chamois (P < 0.05). AQP7 was located in the acrosome of both epididymal and ejaculated spermatozoa, as well as in the cytoplasmic droplet of the epididymal spermatozoa of all three species. No differences were seen between the species with respect to the percentage of spermatozoa showing AQP7. AQP10 was located mainly in the mid-piece, principal piece and end piece of the sperm tail in both epididymal and ejaculated spermatozoa. The percentage of mouflon spermatozoa with AQP10 in the end piece was higher in the cauda epididymal than in the ejaculated spermatozoa (P < 0.05). In conclusion, except for AQP10 in the mouflon, the locations of the studied AQPs are similar in epididymal and ejaculated spermatozoa, with inter-species differences seen only for AQP3. Further studies are needed to determine what this might mean with respect to sperm cryopreservation.

Historically, reproductive health in wildlife species has been evaluated primarily via immunoassay detection of fecal and urinary steroid hormone metabolites. This combination of sample type, biomarker category, and assay has been preferred for decades due to the ease of assessing reproductive health through the evaluation of stable compounds in easily collected biological samples using a cost-effective method. Increasingly, beginning with high performance liquid chromatography (HPLC) and more recently with convergence chromatography and ultra HPLC coupled with mass spectrometry (MS), wildlife studies are incorporating more sensitive and specific high-throughput technologies for the assessment of not only steroid hormone metabolites but proteins as well. Of note, a comprehensive health evaluation requires the measurement of biological readouts that modulate reproduction such as: glucocorticoids, leptin, insulin, thyroid hormones, melatonin, the microbiome, and markers of inflammation. Emerging modulatory biomarkers of reproductive health include acute phase proteins, microRNAs, and reactive oxygen species. Several of these biomarkers require application of newer technologies such as LC-MS/MS and sequencing, which demonstrates the need for the field of wildlife reproductive biology to diversify from its reliance on immunoassays. Importantly, endocrine disrupting chemicals adversely affect many aspects of reproductive function and evaluation of these compounds requires high throughput technology such as LC-MS/MS. The application of sequencing, particularly Next Generation Sequencing of bulk RNA (RNA-Seq) and single cell RNA-Seq, is uncommon in studies of wildlife reproductive health. However, as the cost of these methods decreases and consortiums of wildlife researchers band together to raise funds in support of studies using these technologies, their use will become more routine. Future research should focus on integration of known biomarkers of related systems into comprehensive reproductive assessments and the development of new biomarkers which are sensitive, precise, and employ non-invasive methodologies for the assessment of reproductive health of wildlife species.

The main drawback in developing in vitro embryo production (IVP) systems in wild species, such as the Iberian red deer, is that access to these animals is usually restricted, and long distances from the collection site to the laboratory are usually inevitable. Prolonged ovary storage is known to negatively influence the quality and developmental competence of the oocytes used for IVP. To overcome this issue, we evaluated the effect of adding a caspase-3 inhibitor, z-DEVD-fmk, to the in vitro maturation media to improve the quality and developmental potential of Iberian red deer oocytes. Oocytes were in vitro matured with and without z-DEVD-fmk, and the following parameters were analyzed: viability, early apoptosis, caspase-3 activity, DNA fragmentation, and relative abundance of mRNA transcript related to apoptosis. Moreover, oocyte maturation and blastocyst rates were also assessed. The results showed that z-DEVD-fmk decreased early apoptosis (inhibitor= 44.44 ± 3.6% vs. control= 60 ± 2.79%), DNA fragmentation (inhibitor= 57.83 ± 1.91% vs. control= 74.62 ± 1.91%), caspase-3 activity (inhibitor= 41.88 ± 3.42% vs. control= 67.10 ± 3.42%) and the relative abundance of TP53 and ITM2B transcripts, as well as increased the number of live (inhibitor= 41.48 ± 2.32% vs. control= 20 ± 1.8%) and in vitro-matured oocytes (inhibitor= 88.18 ± 1.99% vs. control= 74.01 ± 1.99%) rates. Nevertheless, the blastocyst production was not different between both experimental groups (inhibitor: 7.35 ± 2.30 vs. control: 13.77 ± 2.30). The supplementation of z-DEVD-fmk to the maturation medium improved the quality of Iberian red deer oocytes. Further research and alternative strategies are needed to evaluate if this inhibitor could still enhance the developmental potential of oocytes during prolonged ovarian transport.

The giant anteater (superorder Xenarthra) is listed as Vulnerable by the International Union for Conservation of Nature (IUCN) and a low reproductive rate is considered one of the factors contributing to population decline of the species. Nevertheless, little is known on reproductive features in male giant anteaters and, in this regard, microscopic testis morphology and spermatogenesis were studied in roadkill specimens in Brazil. Characteristics of germ cell populations resembled descriptions in other eutherian mammals including other xenarthran species. Furthermore, eight stages of the seminiferous epithelium cycle could be defined. The proposed staging system offers baseline data for assessing impairments or seasonal changes in spermatogenesis and thus allows future studies on reproductive health and reproductive seasonality in male giant anteaters.