Effect of Different Vitrification Techniques on Viability and Apoptotic Index of Domestic Cat Testicular Tissue Cells.

Vitrification is essential for successful tissue cryopreservation and biobanking in wild cats. This study aimed to compare different methods of vitrification (Ovarian Tissue Cryosystem-OTC, Straws-STW, and Solid Surface vitrification-SSV) for testicular fragment vitrification in tom cats. Testicular fragments were recovered from five adult tom cats and subjected to equilibrium vitrification using different cryovials and methods under the same conditions of vitrification solutions and cryoprotectants. The efficiencies of the methods were evaluated using histological analysis of spermatogonia and Sertoli cell nuclei, seminiferous tubular basement membrane detachment, and the gonadal epithelium shrinkage score scale. Cell viability was assessed using Hoechst PI and Terminal deoxynucleotidyl transferase nick end labeling (TUNEL) assay. The results showed that OTC is an effective vitrification method for maintaining the distinction between spermatogonia and Sertoli cells. OTC was similar to the control for basal membrane detachment parameters (p = 0.05). Epithelial shrinkage was low in the SSV group, which showed the highest percentage of viable cells among the vitrified groups (p = 0.0023). The OTC and SSV vitrification methods were statistically similar in terms of the percentage of TUNEL-positive cells (p = 0.05). Therefore, OTC and SSV provide favorable conditions for maintaining viable cat testicular tissue cells after vitrification.

Micromorphological and ultrastructural description of spermatozoa from squirrel monkeys (Saimiri collinsi Osgood, 1916).

Saimiri collinsi is used as an animal model in biotechnology research for conservation of species from the genus Saimiri. However, the development of biotechnologies depends on a proper knowledge of the sperm morphology to understand the basic aspects of sperm physiology, as potential male fertility depends on different cellular sperm structures. With this purpose, this study characterized the micromorphological and ultrastructural characteristics of squirrel monkeys (Saimiri collinsi) sperm using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM electromyography revealed that a normal Saimiri collinsi sperm measures 71.7 ± 0.7 µm with lateral tail insertion, a paddle-shaped flattened head and an acrosome occupying most of the head. TEM also showed that the middle piece is characterized by a central 9 + 2 microtubule axoneme surrounded by nine dense fibres, and that the mitochondria were juxtaposed, forming the mitochondrial sheath. Here we provide the first micromorphological and ultrastructure description of S. collinsi sperm.

Extender supplementation with catalase maintains the integrity of sperm plasma membrane after freezing-thawing of semen from capuchin monkey.

We aimed to evaluate the effect of supplementation of ACP-118® extender with the antioxidant catalase (10 and 50 µg/ml) on Sapajus apella sperm motility, vigour, and plasma membrane integrity during the processes of seminal liquefaction, cooling, and freezing. Catalase did not affect any of the evaluated parameters after semen dilution or cooling. Cryopreserved sperm in the presence of 50 µg/ml catalase presented a plasma membrane integrity similar to that fresh sperm, however.

Seminal coagulation and sperm quality in different social contexts in captive tufted capuchin monkeys (Sapajus apella).

In the present study, we aimed to assess the influence of different social contexts on the seminal coagulation and sperm quality in captive tufted capuchin monkeys. For this, males were housed either individually, in mixed-sex groups (with females), or in male-only groups. Monkeys were housed in cages and each cage type (i.e., individual or group cage) was placed in a different room. Forty-one males were subjected to semen collection by rectal electroejaculation. The degree of seminal coagulation was determined on a scale of I-IV. Seminal volume, sperm concentration, sperm motility, vigor, and plasma membrane integrity were evaluated for all ejaculate samples. All ejaculates collected showed degrees of coagulation between II and IV, where the majority presented coagulation degree IV, when collected from animals housed in groups. No statistical differences among percentages of coagula degree when samples were collected from males housed individually. Animals housed in group cages (male-only groups and mixed-sex groups) showed a significantly higher percentage of ejaculates at degree IV than males housed individually. Seminal volume was not affected by the coagula degree but by the housing system, where animals housed individually showed the highest volume (543 µl) when compared with those animals from male (273 µl) and mixed-sex (318 µl) groups. No differences were observed in semen volume when comparing male-only groups with mixed-sex groups. Sperm motility was affected by both housing system and coagula degree. Samples with coagula degree IV from animals housed individually showed the highest (72%) sperm motility percentages. Sperm plasma membrane integrity was lower when samples were presenting coagula degree II + III and collected from male- (17%) or mixed-sex (23%) groups. However, this housing system effect was not observed when sperm was obtained from coagula degree IV semen. Sperm vigor was neither affect by housing system or coagula degree.

Morphologic analysis of sperm from two neotropical primate species: comparisons between the squirrel monkeys Saimiri collinsi and Saimiri vanzolinii.

Sperm morphometry can be applied to identify different animal groups and species and to evaluate sperm quality. Furthermore, knowledge on species-specific differences will help to enhance biological information, as well as to develop efficient reproductive technologies. The aims in the present study were to describe sperm morphometry from the recently characterized species S. collinsi and S. vanzolinii, to verify if the morphometric sperm patterns are similar or different between both species, and to determine if the sperm morphometry is affected by the levels of sperm defects using the S. collinsi as a model. Semen was collected from S. collinsi (n = 10) and S. vanzolinii (n = 2) monkeys, and sperm was submitted to morphological analysis. From the 10 samples from S. collinsi, five presented sperm of poor quality and two subgroups were formed for this species, i.e. high and poor quality sperm. Data on sperm motility and vigour were analysed, as well morphometric parameters on sperm head and tail. It was observed the normal morphometry was correlated with high quality sperm. Poor quality sperm presented smaller and 7% more ellipticity in their head, when compared with high quality sperm. Sperm from S. vanzolinii presented larger head than those from S. collinsi, but tail lengths were similar. Sperm morphometry can be used as a complementary tool to predict sperm motility and vigour for the S. collinsi species, and S. collinsi appear as a suitable model for S. vanzolinii.

Cooling and freezing of sperm from captive, free-living and endangered squirrel monkey species.

Germoplasm banking is an important tool for the preservation of genetic material from Neotropical primates in captivity, and from free living species, especially the endangered ones like Saimiri vanzolinii (Black-headed squirrel monkey), a primate with a low incidence area (870 km(2) of floodplains) in the southern part of the Mamirauá Sustainable Development Reserve, Brazil. Therefore, in the present study we aimed to develop a sperm cryopreservation protocol comparing sperm cooling in presence (T1) and absence (T2) of egg yolk, and to test freezing protocols to preserve semen from captive (Saimiri collinsi), and free-living (Saimiri vanzolinii, Saimiri cassiquiarensis and Saimiri macrodon) New World primates. Cooling preserved sperm of S. collinsi in all evaluated microscopic parameters, except for sperm motility. No differences were observed among the treatments, indicating that semen of this species can be cooled without egg yolk. Freezing did not affect sperm quality of S. collinsi, except plasma membrane integrity that was negatively affected. Generally, a good maintenance rate was observed between cooling and thawing of semen for the four species, showing the positive translational application of protocols from S. collinsi to the free-living species. Developed freezing protocol proved to be useful for sperm cryopreservation of S. collinsi and in field conditions.

Embryo production by parthenogenetic activation and fertilization of in vitro matured oocytes from Cebus apella.

The efficiency of in vitro fertilization (IVF) depends on the viability of spermatozoa. For capuchin monkeys (Cebus apella), in vitro capacitation of spermatozoa is challenging because of their unique seminal coagulum. Motile spermatozoa can be obtained after liquefaction of the semen coagulum in coconut water-based solution. The objective of the present study was to establish an optimal in vitro maturation (IVM) protocol for capuchin monkeys and to observe the effect of follicle stimulating hormone (FSH) and luteinising hormone (LH) on IVF and parthenogenetic activation (PA) of oocytes collected from unstimulated females. We assessed spermatozoa quality after recovery from seminal coagulum using the solution ACP-118® as an extender. Oocytes were matured in vitro for 36 or 40 h and subjected to IVF or PA by applying ionomycin combined either with 6-dimethylaminopurine (6-DMAP) or roscovitine. In total, 87% of oocytes reached metaphase II (MII) after 40 IVM and 4-cell embryo production was obtained after IVF and parthenogenesis using ionomycin/6-DMAP. ACP-118® was used successfully to harvest viable spermatozoa from semen coagulum and in the preservation of spermatozoa, which were able to fertilize oocytes in vitro.

Semen coagulum liquefaction, sperm activation and cryopreservation of capuchin monkey (Cebus apella) semen in coconut water solution (CWS) and TES-TRIS.

The objectives of the present study were to test the effect of coconut water solution and TES-TRIS on the seminal coagulum liquefaction, sperm activation in fresh diluted semen, and on the cryopreservation of semen from capuchin monkeys (Cebus apella). Semen was collected from six males by electro-ejaculation, diluted in TES-TRIS or coconut water solution (CWS), and incubated at 35°C until the coagulated fraction of the semen was completely liquefied. In the experiment I, after liquefaction, samples were diluted in TES-TRIS or CWS, plus 6 and 10mM/mL of caffeine. Sperm motility and vigor were evaluated during 5h. For experiment II, after liquefaction, semen samples were extended in TES-TRIS (3.5% glycerol in the final solution) or CWS (2.5% glycerol in the final solution), cryopreserved and stored in liquid nitrogen for 1 week. The seminal coagulum was liquefied in (mean±SDM) 4.5±1.7 and 2.8±1.1h in TES-TRIS and CWS, respectively. Sperm were motile in TES-TRIS and CWS for 5.0±1.4 and 1.0±0.5h, respectively. The mean motility in this period was 38±22% (TES-TRIS) and 22.0±16.0 (CWS). Motility increased after caffeine addition only in samples diluted in CWS containing 6mM (22.5±16.0) or 10mM (28.0±19.0) caffeine. Post-thaw live sperm percentage was 26.2% in TES-TRIS and 13.2% in CWS. For cryopreservation of semen from C. apella TES-TRIS (3.5% glycerol) was more appropriate than CWS (2.5% glycerol). CWS+caffeine potentially increase sperm motility and may be useful in artificial insemination of fresh diluted semen.