A review on reproductive biotechnologies for conservation of endangered mammalian species.

Embryo technology in conservation efforts for endangered felids.

https://stud.epsilon.slu.se/3424/1/thuwanut_p_111024.pdf

The effect of antioxidants on motility, viability, acrosome integrity and DNA integrity of frozen-thawed epididymal cat spermatozoa.

Embryogenesis in conservation biology - or, how to make an endangered species embryo

Ovarian sensitivity to exogenous gonadotropins was assessed in the cheetah (Acinonyxjubatus) and clouded leopard (Neofelis nebulosa) to help optimize artificial insemination (Al). Eighteen female cheetahs were used on 29 occasions and were given i.m. injections of 100, 200, or 400 IU eCG and 100 or 250 IU hCG 80 h later. Twenty-three female clouded leopards were treated i.m. on 27 occasions with 25, 50, 75, 100, 200, or 400 IU eCG followed 80 h later with 75, 140, or 280 IU hCG. Ovaries were examined laparoscopically at 43-48 h after hCG in cheetahs and 39-50 h in clouded leopards. All gonadotropin dosages stimulated ovarian activity in both species, but ovulation success and corpus luteum (CL) morphology varied (p < 0.05) with treatment. For both species, the highest and intermediate eCG dosages resulted in ovulation in a high proportion (72-100%) of females. The lowest eCG dosage, although capable of stimulating follicular development, compromised ovulation and resulted in few (< 26%) postovulatory females. For each species, small CL (2-4-mm diameter) were observed with the highest and lowest eCG dosage, and large CL (5-8-mm diameter) were associated with intermediate eCG dosages. Aged CL (10-12-mm diameter) were observed in 4 of 23 (17.4%) clouded leopards with no prior male exposure, indicating occasional spontaneous ovulation. Nineteen laparoscopic intrauterine Al procedures were performed in eCG/hCG-treated postovulatory cheetahs. Eighteen Al procedures were conducted in eCG/hCG-treated postovulatory clouded leopards. Six of the 13 cheetahs (46%), all in the 200-lU eCG/100-IU hCG group, became pregnant, in contrast to none of the clouded leopards. This study has revealed differences in ovarian activity in two wild felid species as a result of changes in exogenous gonadotropin dosage. Because of this dose-effect response, this comparative approach is necessary to identify a gonadotropin regimen that can mimic "normalcy." Even then, the relatively high Al success in the cheetah compared to the clouded leopard suggests that factors other than ovarian response can dictate the efficiency of assisted reproduction in this taxon.

Sensitivity to exogenous gonadotropins for ovulation induction and laparoscopic artificial insemination in the cheetah and clouded leopard.

Sperm-oocyte interaction in vitro was studied in the cheetah, a species known to produce poor quality ejaculates and to experience low rates of fertility. Twelve female cheetahs were injected (i.m.) with eCG followed by hCG 84 h later. Twentyfour to 26 h post hCG, each was subjected to laparoscopic oocyte aspiration. A sperm motility index (SM!) was calculated for each of 9 cheetah sperm donors that produced ejaculates averaging 41.3 ± 22.9 X 10� motile sperm and 28.4 ± 4.9% structurally normal sperm. Each ejaculate was used to inseminate cheetah oocytes from 1 or 2 females and salt-stored, domestic cat oocytes. The presence of ovarian foffictes (� 1.5 mm in diameter) showed that all females responded to exogenous gonadotropins (range, 11-35 follicles/female). A total of 277 cheetah oocytes was collected from 292 follicles (94.9% recovery; 23.1 ± 2.2 oocytes/ female). Of these, 250 (90.3%) qualified as mature and 27 (9.7%) as degenerate. Of the 214 mature oocytes inseminated, 56 (26.2%) were fertilized, and 37 (17.3%) cleaved to the 2-cell stage in vitro; but the incidence of in vitro fertilization (IVF) varied from 0 to 73.3% (p 0 after 6 h coincubation versus an SM! = 0 at this time, the mean fertilization rates were 28/44 (63.6%) and 0/37(0%), respectively (p 0.05) among allmales, there was a positive correlation between the number of sperm reaching the inner half of the ZP and fertilization rate in vitro (r = 0.82; p < 0.05). Compared to WE efficiency in the domestic cat and tiger as reported in earlier studies, LVI’ efficiency in the cheetah is low. Because oocytes from 11 of 12 cheetahs were fertilized in vitro, there is no evidence that the female gamete is incompetent. Although sperm pleiomorphisms may contribute to poor reproductive performance, examination of the data on the basis of individual sperm donors reveals that effective gamete interaction in the cheetah is dictated, in part, by sperm motility.

/pdf/correlation-of-sperm-viability-with-gamete-interaction-and-305kz9b8g4.pdf

E Blumer

Papers

Correlation of sperm viability with gamete interaction and fertilization in vitro in the cheetah (Acinonyx jubatus).