Heterologous in vitro fertilization and embryo production for assessment of jaguar (Panthera onca Linnaeus, 1758) frozen-thawed semen in different extenders

Heterologous in vitro fertilization (IVF) is an important tool for assessing fertility of endangered mammals such as the jaguar, considering difficult access to females for artificial insemination and to obtain homologous oocytes. We aimed to evaluate the fertility of jaguar sperm cryopreserved with different extenders, using domestic cat oocytes to assess the development of hybrid embryos. Semen from four captive jaguars was obtained by electroejaculation. Samples were cryopreserved in powdered coconut water (ACP-117c) or Tris extender containing 20% egg yolk and 6% glycerol. Thawed spermatozoa were resuspended (2.0 × 10⁶ spermatozoa/mL) in IVF medium and co-incubated with cat oocytes matured in vitro for 18 h. Presumptive zygotes were cultured for 7 days. After 48 h, cleavage rate was evaluated, and non-cleaved structures were stained for IVF evaluation. On days 5 and 7, the rate of morula and blastocyst formation was assessed. Data were analyzed using the Fisher exact test (p < 0.05). No difference was observed between ACP-117c and Tris extenders, respectively, for oocytes with 2nd polar body (2/51, 3.9 ± 2.9% vs. 2/56, 3.6 ± 3.1%), pronuclear structures (5/51, 9.8 ± 4.7% vs. 8/56, 14.3 ± 8.0%), and total IVF rates (7/36, 19.4 ± 5.0% vs. 10/37, 27.0 ± 13.8%). All the samples fertilized the oocytes, with 22.9 ± 3.2% (16/70) and 16.7 ± 3.6% (12/72) cleavage of mature oocytes for ACP-117c and Tris extenders, respectively. Morula rates of 4.3 ± 2.3% (3/70) and 5.6 ± 2.2% (4/72) were observed for ACP-117c and Tris, respectively. Only the Tris extender demonstrated blastocyst production (2/12, 16.7 ± 1.5% blastocyst/cleavage). We demonstrated that jaguar ejaculates cryopreserved using ACP-117c and Tris were suitable for IVF techniques, with blastocyst production by ejaculates cryopreserved in Tris. This is a first report of embryos produced in vitro using jaguar sperm and domestic cat oocytes through IVF.

Effects of different concentrations of eugenol in maturation medium on bovine oocytes, oxidative status and preimplantation embryos

ContextEugenol is a bioactive compound with defined attributes, including a role in reducing oxidative stress. Therefore, it is an interesting candidate for in vitro embryo production that has an environment that favours the formation of reactive oxygen species.AimThe objective of the study was to evaluate different concentrations of eugenol in bovine oocytes during in vitro maturation to observe the oxidative status and embryonic development.MethodsOocytes were allocated into five groups: control (without antioxidant), 100μM cysteamine, 83μM eugenol (E83), 100μM eugenol and 120μM eugenol. Three experiments were performed with 23 replicates. Oocytes were evaluated for metaphase II, first polar body, cytoplasmic maturation, cumulus cell expansion and viability. Oxidative status was measured by mitochondrial membrane potential, reactive oxygen species and glutathione. Oocytes were artificially activated and cultured in vitro.Key resultsThe presence of eugenol at 83μM improved the metaphase II rate compared with all treatments (P&lt;0.05). E83 and 100μM cysteamine improved first polar body extrusion, cumulus cell expansion, viability and mitochondrial aggregation rates (P&lt;0.05). All antioxidant treatments resulted in increased cytoplasmic maturation and decreased mitochondrial membrane potential (P&lt;0.05). Reactive oxygen species levels decreased, and glutathione levels increased with E83 and 100μM cysteamine treatments (P&lt;0.05). Finally, the E83 group increased the cleavage rates, embryo development, number of expanded blastocysts and number of blastomeres (P&lt;0.05).ConclusionsA low concentration of eugenol (83μM) is sufficient to generate a significant effect, attenuating the oxidative status and optimising in vitro maturation and embryo development.ImplicationsThis study provides information of a new natural antioxidant with defined concentration, 83μM eugenol, representing a lower cost alternative capable of improving the efficiency of in vitro embryo production in cattle.

Effects of vitrification techniques on the formation of skin cryobank of the ocelot (Leopardus pardalis)

BACKGROUND

Skin cryobanks represent important tools for the conservation of the maximum genetic representation of a population, especially those with a certain degree of threat to extinction, such as the ocelot. A relevant step towards the proper establishment of these banks is the definition of adequate cryopreservation techniques for the conservation of the skin.

OBJECTIVE

We evaluated the effects of two different techniques [direct vitrification in cryovials (DVC) and solid-surface vitrification (SSV)] for the preservation of ear skin derived from ocelot.

MATERIALS & METHODS

For both techniques, we vitrified the ear skin using Dulbeccos modified Eagles medium with 3.0 M dimethyl sulfoxide, 0.25 M sucrose, and 10% fetal bovine serum. Non-cryopreserved tissues were used as control (control group). All tissues were analyzed for their morphometric characteristics by conventional histology and morphological / functional analysis by cell ability during the culture.

RESULTS

While tissues cryopreserved by DVC showed similar values for dermis thickness and number of perinuclear halos to the control, tissues cryopreserved by SSV showed similarities to the control regarding the number of melanocytes, percentage of collagen fibers, and numbers of viable cells by apoptosis analysis. Additionally, none of the vitrification techniques affected stratum corneum thickness, number of keratinocytes, tissue proliferative activity, cell viability, or metabolism.

CONCLUSION

Both vitrification techniques (DVC and SSV) can be used for the conservation of ocelot skin; however, SSV guarantees a higher cellular quality after in vitro tissue culture in most of the parameters evaluated, such as viability, metabolism, and apoptosis analysis. doi.org/10.54680/fr23110110412.

Microbiological load and preantral follicle preservation using different systems for ovarian tissue vitrification in the red-rumped agouti

We evaluated the effect of open and closed systems used for ovarian tissue vitrification on the microbiological load and preservation of preantral follicles (PAFs) in the red-rumped agoutis. The ovaries from eight females were recovered and fragmented, with four cortexes fragments immediately fixed and evaluated (fresh group). The other fragments were processed for the solid-surface vitrification method (SSV) or an ovarian tissue cryosystem (OTC) using fetal calf serum, ethylene glycol, and sucrose as cryoprotectants, stored for two weeks, and rewarmed. Subsequently, fragments were subjected to a 24-h in vitro culture and assessed for microbiological load, PAF morphology, and DNA integrity. There was no fungal contamination; however, the vitrified samples from two individuals showed bacterial contamination of 79 200 colony forming units per milliliter (CFU)/mL for SSV and 3120 CFU/mL for OTC. From those samples, a total of eight different types of bacterial colonies were isolated and identified as coagulase-negative Staphylococci and Gram-positive bacilli. Regarding PAF morphology, both systems provided adequate preservation, with values higher than 70% normal follicles observed before and after culture. The TUNEL assay revealed that both SSV (52.39%) and OTC (41.67%) could preserve DNA integrity after vitrification and after 24 h of culture. In summary, both open and closed systems were equally efficient in preserving agouti ovarian tissues, especially concerning the preantral follicle morphology and DNA integrity; however, the OTC seems to provide a less adequate environment for bacterial proliferation.

Evaluation of different cryoprotectant solutions for the cryopreservation of somatic tissues of Dasyprocta leporina (Linnaeus, 1758)

BACKGROUND

Somatic tissue banks represent important tools for the conservation of wild mammals, aiming at the immediate maintenance and safeguarding of biological samples. For agouti, Dasyprocta leporina, studies on the formation of these banks are still scarce, especially regarding protocols of the best cryoprotectant solution employed.

OBJECTIVE

To optimize the cryoprotectant solution [ethylene glycol (EG), dimethyl sulfoxide (DMSO), sucrose (SUC)] used for the cryopreservation of agouti somatic tissues.

MATERIALS AND METHODS

We treated ear tissues with various cryoprotectant solutions: 3.0 M EG (EG group), 3.0 M EG and 0.25 M SUC (EG-SUC group), 3.0 M DMSO (DMSO group), 3.0 M DMSO and 0.25 M SUC (DMSO-SUC group), 1.5 M EG and 1.5 M DMSO (EG-DMSO group) and 1.5 M EG, 1.5 M DMSO and 0.25 M SUC (EG-DMSO-SUC group). Non-cryopreserved tissues were used as controls. All tissues were analyzed for their ultrastructural and morphometric characteristics by scanning electron microscopy and conventional histology.

RESULTS

EG-DMSO-SUC was found to be the optimal cryoprotectant solution in terms of the evaluated parameters, such as thickness of the dermis and skin, number of perinuclear halos, proliferative potential, number of empty lacunas and degenerated chondrocytes.

CONCLUSION

Agouti somatic tissue cryopreservation may serve for its conservation and as an experimental model for the development of preservation methods for species of the same genus that are either vulnerable or critically endangered.

Effects of somatic tissue cryopreservation on puma (Puma concolor L, 1771) tissue integrity and cell preservation after in vitro culture

Somatic resource banks play a crucial role in the conservation of genetic diversity, allowing for the preservation of biological samples from different populations. Puma somatic cells can be recovered from these banks and used in assisted techniques toward enhancing their multiplication and conservation. In response to the population reduction of this ecologically importance species, we aimed to evaluate the capacity of cryopreservation of somatic tissues on the maintenance of the integrity and quality of the cells recovered after culture, with the aim of establishing a somatic tissue bank that will allow for the safeguarding of a wide genetic sampling of pumas. Cryopreservation increased the thickness of the corneum layer in the tissues, and the number of perinuclear halos and empty gaps. Nevertheless, cryopreservation was able to maintain normal fibroblast patterns, even showing an increase in the percentage of collagen fibers. Cryopreservation maintained the proliferative potential of the tissues and the parameters evaluated during in vitro culture, mainly regarding the viability, proliferative activity, and apoptosis levels. Nevertheless, cells from cryopreserved tissues showed decreased metabolism and mitochondrial membrane potential when compared to cells from non-cryopreserved tissues. In summary, we demonstrated for the first time that puma somatic tissues subjected to cryopreservation are viable and maintain tissue integrity, featuring minimal changes after warming. Although viable somatic cells are obtained from these tissues, they undergo alterations in their metabolism and mitochondrial membrane potential. Improvements in the conservation conditions of somatic samples are needed to increase the quality of somatic tissue banks in this species.

Influence of freezing techniques and glycerol-based cryoprotectant combinations on the survival of testicular tissues from adult collared peccaries

The objective of the study was to evaluate the effects of different cryopreservation techniques including glycerol-based cryoprotectant combinations on the structure and viability of testicular tissues from adult collared peccaries. Tissue biopsies (3.0 mm³) from 5 different individuals were allocated to 10 different groups: fresh control; slow freezing (SF), conventional vitrification (CV), or solid-surface vitrification (SSV); each of them using three different combinations of cryoprotectants [dimethyl sulfoxide (DMSO) + ethylene glycol (EG); DMSO + Glycerol; and EG + Glycerol]. After thawing/warming, samples were evaluated for histomorphology, viability, proliferative capacity potential, and DNA integrity. Most effective preservation of testicular histomorphology was achieved using SF and CV with DMSO + EG. However, the use of glycerol-based cryoprotectant combinations increased the occurrence of tubular cell swelling, tubular cell loss and shrinkage from the basal membrane. Cell viability was comparable among cryopreservation methods and cryoprotectant combinations. Regarding cell proliferative capacity, the use of SF with EG + Glycerol and SSV with DMSO + Glycerol impaired the conservation of spermatogonia proliferative potential compared to other treatments. Moreover, CV with DMSO + EG was better than SF with EG + Glycerol for Sertoli cell proliferation potential. Regarding DNA integrity, less damage occurred when using SF with DMSO + EG while more fragmentations were observed when using CV with EG + Glycerol or DMSO + Glycerol as well as SSV with EG + Glycerol or DMSO + Glycerol. In sum, SF and CV appeared to be the most suitable methods for the cryopreservation of adult peccary testicular tissues. Additionally, the use of glycerol-based cryoprotectant combinations did not improve testicular tissues preservation with DMSO + EG being the most efficient option.

Cryopreservation of Spix's yellow-toothed cavy epididymal sperm using Tris- and coconut water-based extenders supplemented with egg yolk or Aloe vera

Addressing the establishment of biobanks for the conservation of wild hystricomorph rodents' germplasm, we verified the effects of different extenders and distinct concentrations of non-permeant cryoprotectants on the sperm parameters of Spix's yellow-toothed cavies. Nine testis-epididymis complexes were used for sperm collection by retrograde washing using Tris or a powdered coconut water extender (ACP®-116c). Spermatozoa were diluted and frozen with the same extenders supplemented with egg yolk or Aloe vera at a 10% or 20% concentration. After recovery and cryopreservation, all samples were evaluated for sperm kinetic parameters, morphology, membrane integrity, osmotic response, and sperm-binding capability using an egg yolk perivitelline membrane assay. After recovery, no differences were observed between Tris and ACP®-116c that provided 515.4 × 10⁶ sperm/mL and 561.6 × 10⁶ sperm/mL, presenting >65% motile sperm, respectively. After cryopreservation, most effective preservation of sperm kinetic parameters (68.1 ± 5.9% motile sperm) and membrane integrity (48.2 ± 7.4%) was provided by Tris extender supplemented with 10% egg yolk. However, both extenders supplemented with any concentration of egg yolk or Aloe vera presented similar preservation of osmotic response and sperm-binding ability after cryopreservation. In summary, we suggest the use of a Tris extender supplemented of 10% egg yolk for cryopreservation of Spix's yellow-toothed cavy epidydimal sperm.

Pyroligneous acid from Mimosa tenuiflora and Eucalyptus urograndis as an antimicrobial in dairy goats

AIMS

To evaluate the applicability of the Mimosa tenuiflora and Eucalyptus urograndis pyroligneous acids (PAs) as alternative antiseptics in dairy goats.

METHODS AND RESULTS

Cytotoxicity was evaluated in vitro using bacteria, as well as in vivo using goats, and the influence of PAs on the physicochemical parameters of fresh milk were examined. The cytotoxicity of PAs was evaluated in terms of morphology, cell viability and metabolic activity of goat tegumentary cells. The PA of M. tenuiflora had results similar to those of 2% iodine. For the in vitro tests, strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were used with the well technique, demonstrating inhibition halos greater than 9 mm. In the in vivo test, 15 animals were used per phase of the experiment, and the plate counting technique showed that there was antiseptic action of both extracts, with emphasis on the M. tenuiflora PA. Physicochemical analysis of the milk showed that neither PAs interfered with its physical-chemical parameters.

CONCLUSIONS

The PA of M. tenuiflora presented potential as an alternative antiseptic in dairy goats.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates the use of PA as an antimicrobial agent in animals.

CONSERVAÇÃO DE TECIDOS SOMÁTICOS DE CATETOS (Pecari tajacu LINNAEUS, 1758) SUBMETIDO A DIFERENTES CONDIÇÕES DE ARMAZENAMENTO

O objetivo foi avaliar a influência da conservação [refrigeração a 5°C e vitrificação] sobre tecidos somáticos de catetos. O experimento foi dividido em duas etapas. Na primeira etapa, fragmentos foram refrigerados por 24 (R-24) e 48 h (R-48) e comparados com amostras não refrigeradas (C). Na segunda etapa, fragmentos foram refrigerados por 24 (RV-24) e 48 h (RV-48) seguidos da vitrificação, e comparados com fragmentos apenas vitrificados (V). Na primeira etapa, embora a espessura da epiderme não tenha sido afetada pela refrigeração por 48 h, a espessura da derme foi reduzida tanto no período de 24 h quanto de 48 h. Além disso, enquanto uma redução de fibroblastos dérmicos foi apenas evidenciada no grupo R-48, o aumento de halos perinucleares da epiderme foi observado em todos os grupos refrigerados. Na segunda etapa, tanto a espessura da epiderme, quanto da derme e total foram afetadas pela vitrificação após a refrigeração por 48 h. Além disso, enquanto uma redução de fibroblastos dérmicos foi apenas evidenciada no grupo RV-48, o aumento de halos perinucleares da epiderme foi observado em todos os grupos vitrificados. Assim, independente do período de armazenamento, a refrigeração afetou a qualidade dos tecidos somáticos de catetos, sendo esses efeitos acentuados quando os fragmentos foram refrigerados por 48 h e vitrificados. Portanto, sugere-se, quando necessário, o período de 24 h de refrigeração para amostras somáticas derivadas de catetos que irão ainda ser vitrificadas.

Establishment, characterization, and cryopreservation of cell lines derived from red-rumped agouti (Dasyprocta leporina Linnaeus, 1758) - A study in a wild rodent

Somatic cells can be used for rescuing wild mammals of ecological and economic importance, such as red-rumped agouti, through their application in advanced technologies. Thus, appropriate cell isolation, culture, and storage through cryopreservation can ensure the future safe use of these cells. We aimed to establish and evaluate the effects of culture time (second, fifth, and eighth passages) and cryopreservation on the morphology, viability, metabolism, proliferative activity, reactive oxygen species (ROS) levels, mitochondrial membrane potential (ΔΨm), and apoptosis on somatic cells derived from red-rumped agouti skin. Initially, we identified six dermal fibroblast lines by morphology, immunophenotyping, and karyotyping assays. In vitro culture after the second, fifth, and eighth passages, as well as the cryopreservation conditions used did not affect the metabolism or level of apoptosis. Nevertheless, cells in the fifth passage featured a reduction in proliferative activity and an increase in ROS levels when compared to second and eighth passage cells. Moreover, cryopreservation resulted in reduced ΔΨm when compared to non-cryopreserved cells. Additionally, cryopreserved cells showed a reduction in viability immediately after thawing; nevertheless, the viability of these cells was re-established after 11 days of in vitro culture and was similar to that of non-cryopreserved cells. In conclusion, we have shown that viable fibroblasts can be obtained from red-rumped agouti skin, featuring minimal changes after eight passages in in vitro culture systems. Additionally, adjustments to the cryopreservation protocol are necessary to reduce cellular oxidative stress caused by low temperatures.

Amifostine protects from the peripheral sensory neuropathy induced by oxaliplatin in mice

Sensory neuropathy is a dose-limiting side effect of oxaliplatin-based cancer treatment. This study investigated the antinociceptive effect of amifostine and its potential neuroprotective mechanisms on the oxaliplatin-related peripheral sensory neuropathy in mice. Oxaliplatin (1 mg/kg) was injected intravenously in Swiss albino male mice twice a week (total of nine injections), while amifostine (1, 5, 25, 50, and 100 mg/kg) was administered subcutaneously 30 min before oxaliplatin. Mechanical and thermal nociceptive tests were performed once a week for 49 days. Additionally, c-Fos, nitrotyrosine, and activating transcription factor 3 (ATF3) immunoexpressions were assessed in the dorsal root ganglia. In all doses, amifostine prevented the development of mechanical hyperalgesia and thermal allodynia induced by oxaliplatin (P<0.05). Amifostine at the dose of 25 mg/kg provided the best protection (P<0.05). Moreover, amifostine protected against neuronal hyperactivation, nitrosative stress, and neuronal damage in the dorsal root ganglia, detected by the reduced expression of c-Fos, nitrotyrosine, and ATF3 (P<0.05 vs the oxaliplatin-treated group). In conclusion, amifostine reduced the nociception induced by oxaliplatin in mice, suggesting the possible use of amifostine for the management of oxaliplatin-induced peripheral sensory neuropathy.

Cryopreservation of Collared Peccary (Pecari tajacu Linnaeus, 1758) Somatic Cells is Improved by Sucrose and High Concentrations of Fetal Bovine Serum

BACKGROUND

The formation of somatic cell banks is affected by, amongst other factors, the cryoprotectant solution used. The selection of an effective solution, therefore, is a primary parameter.

OBJECTIVE

We optimized the cryoprotectant used for collared peccary somatic cell cryopreservation.

MATERIALS AND METHODS

We categorized cells into different groups based on their cryopreservation and evaluated the morphology, viability, proliferative activity, metabolism, and oxidative stress. One group was cryopreserved in 10% DMSO with 10% fetal bovine serum (DMSO-10FBS), and another with 50% FBS (DMSO-50FBS). The cryopreservation of both groups included the presence of 0.2 M sucrose (DMSO-SUC-10FBS and DMSO-SUC-50FBS). Non-cryopreserved cells and cells cryopreserved with 10% DMSO (DMSO) supplemented with 0.2 M sucrose (DMSO-SUC) were used as controls.

RESULTS

There was no difference observed in morphology or viability among the groups. Proliferative activity was reduced in DMSO-10FBS when compared to controls. Although cryopreservation reduced metabolism, no difference was observed among solutions. A lower level of reactive oxygen species was observed in cells of DMSO-SUC-50FBS when compared to other cryoprotectants. Only cells of DMSO-SUC-50FBS had mitochondrial potential similar to non-cryopreserved cells.

CONCLUSION

10% DMSO supplemented with 50% FBS and 0.2 M SUC was observed to be the most efficient cryoprotectant for preserving collared peccary somatic cells.

A Comparative Approach of Cellular Reprogramming in the Rodentia Order

Cellular reprogramming mainly involves induction of reactivation of genes responsible for nuclear plasticity, a process that can be performed in vitro through production of cloned embryos by somatic cell nuclear transfer or by induction of cells into the pluripotent state through exogenous transcription factor expression. While these techniques are already well known and utilized in mice and rats, their application in other rodent species would be greatly beneficial, especially for conservation purposes. Within the diverse Rodentia order, wild species stand out as they play an important role in balancing the ecosystem by facilitating seed diversion, soil aeration, and consequently, reforestation. Many of these species are currently approaching extinction, and application of techniques, such as nuclear reprogramming, aimed at species conservation and multiplication and to produce stem cells is of interest. Thus, in this review, we aimed to present the evolution and success of nuclear reprogramming, mainly highlighting its potential application for the conservation of wild rodents.

Isolation, characterization, and cryopreservation of collared peccary skin-derived fibroblast cell lines

Background

Biobanking of cell lines is a promising tool of support for wildlife conservation. In particular, the ability to preserve fibroblast cell lines derived from collared peccaries is of significance as these wild mammals are unique to the Americas and play a large role in maintaining the ecosystem. We identified collared peccary fibroblasts by immunofluorescence and evaluated their morphology, growth and adherence capacity. Further, we monitored the viability and metabolic activity of the fibroblasts to determine the effects of passage number and cryopreservation on establishment of cell lines.

Methods

Skin biopsies were collected from the peripheral ear region from five adult animals in captivity. Initially, cells were isolated from fragments and cultured in the Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum and 2% antibiotic-antimycotic solution under a controlled atmosphere (38.5 °C, 5% CO₂). We evaluated the maintenance of primary cells for morphology, adherence capacity of explants, explants in subconfluence, cell growth and absence of contamination. Moreover, we identified the fibroblast cells by immunofluorescence. Additionally, to evaluate the influence of the number of passages (first, third and tenth passage) and cryopreservation on establishment of cell lines, fibroblasts were analysed for the viability, metabolic activity, population doubling time (PDT), levels of reactive oxygen species (ROS), and mitochondrial membrane potential (ΔΨm).

Results

All explants (20/20) adhered to the dish in 2.4 days ± 0.5 with growth around the explants in 4.6 days ± 0.7, and subconfluence was observed within 7.8 days ± 1.0. Moreover, by morphology and immunocytochemistry analyses, cells were identified as fibroblasts which presented oval nuclei, a fusiform shape and positive vimentin staining. No contamination was observed after culture without antibiotics and antifungals for 30 days. While there was no difference observed for cell viability after the passages (first vs. third: P = 0.98; first vs. tenth: P = 0.76; third vs. tenth: P = 0.85), metabolic activity was found to be reduced in the tenth passage (23.2 ± 12.1%) when compared to that in the first and third passage (100.0 ± 24.4%, P = 0.006). Moreover, the cryopreservation did not influence the viability (P = 0.11), metabolic activity (P = 0.77), or PDT (P = 0.11). Nevertheless, a greater ΔΨm (P = 0.0001) was observed for the cryopreserved cells (2.12 ± 0.14) when compared to that in the non-cryopreserved cells (1.00 ± 0.05). Additionally, the cryopreserved cells showed greater levels of intracellular ROS after thawing (1.69 ± 0.38 vs. 1.00 ± 0.22, P = 0.04).

Conclusions

This study is the first report on isolation, characterization and cryopreservation of fibroblasts from collared peccaries. We showed that adherent cultures were efficient for obtaining fibroblasts, which can be used as donor cells for nuclei for species cloning and other applications.

Cryopreservation and Culture of Testicular Tissues: An Essential Tool for Biodiversity Preservation

Systematic cryo-banking of reproductive tissues could enhance reproductive management and ensure sustainability of rare mammalian genotypes. Testicular tissues contain a vast number of germ cells, including at early stages (spermatogonia and spermatocytes), that can potentially develop into viable spermatozoa after grafting or culture in vitro, and the resulting sperm cells then can be used for assisted reproductive techniques. The objective of this review was to describe current advances, limitations, and perspectives related to the use of testicular tissue preservation as a strategy for the conservation of male fertility. Testes can be obtained from mature or prepubertal individuals, immediately postmortem or by orchiectomy, but testicular biopsies could also be an alternative to collect samples from living individuals. Testicular fragments can be then cryopreserved by using slow or ultra-rapid freezing, or even vitrification methods. The composition of cryopreservation media can vary according to species-specific characteristics, especially regarding the cryoprotectant type and concentration. Finally, spermatozoa have been usually obtained after xenografting of testicular fragments into severely immunodeficient mice, while this method still has to be optimized after in vitro culture conditions.

Embryonic/Fetal Development, Placentation and Glycosaminoglycans in the Female Reproductive Tract and Placenta

Background: Fetal attachments, placentation and embryonic development have been widely discussed in rodents such as agoutis and cavies, as well as research on glycosaminoglycans (GAGs) in rats and rabbits. Moreover, studies on buffalo, cattle and sheep are described in ruminants, and work has also been reported in sheep with GAGs in placentoma. However, further studies are needed in this regard, since there are reports of economic losses associated with reproductive failures described for cattle such as changes in the chorion and allantois, and in sheep in which changes between the transition from vitelline to allantois circulation have been discussed.  Review: In relation to embryonic development, detailed studies have been described in rodents such as rats (12 days old), desert mouse (15 days old) and agoutis at 30 days. Macroscopic structures such as the cephalic region, nose, optic vesicle, cervical curvature, thoracic and pelvic limbs were observed, as well as microscopic structures such as the pituitary, lung, heart, brain cavity, liver, retina, and ossification regions. There are reports of buffalo and cattle studies in ruminants describing early embryonic development. However, the research in the case of sheep is limited, meaning there is only the ultrasound examination, such as gestational diagnosis and morphometric measurement of the embryonic vesicle. Still, studies with umbilical funicular and placental development of sheep with different gestational ages can be highlighted. Regarding extraembryonic annexes, four important structures which contribute to embryonic maintenance have been reported. These are called the chorion, amnion, allantois and yolk sac, respectively, and are responsible for originating the placenta, embryonic protection, collecting metabolic waste and early embryonic nutrition. In addition, correlating the annexes gives rise to the placentation process, which were described two models; the first is transient, called chorioviteline, and the second is called chorioallantoid, which represents the definitive model. Allied to the gestational process, the importance of glycosaminoglycans (GAGs) and proteoglycans are worth mentioning, as they are essential components of the extracellular matrix. They are related in the implantation process, tissue organization during gestation, and also in placental angiogenesis, as described in ruminants (i.e. involved in the vascular growth that accompanies the development of the placenta), which in turn causes an increase in blood flow in this organ, and constitutes a determining factor for fetal development. Conclusion: Such studies regarding the embryonic development of ruminants are still limited to sonographic description and some information is only available in the context of extraembryonic membranes. For glycosaminoglycans, chondroitin sulfate, dermatan sulfate, heparan sulfate and hyaluronic acid are identified in the reproductive tract and placenta. We intend to produce important information for the reproductive and sanitary management of ruminants with the information in this article, providing data to stimulate new studies aiming to minimize the occurrence of embryonic death and economic losses. In addition, further studies on GAGs are needed to better understand their true correlation with gestation, so they can intercede through supplementation and minimize reproductive losses.

Production of collared peccary (Pecari tajacu Linnaeus, 1758) parthenogenic embryos following different oocyte chemical activation and in vitro maturation conditions

To optimize the protocols for assisted reproductive techniques (ARTs) in collared peccary (Pecari tajacu Linnaeus, 1758), we evaluated various conditions for oocyte in vitro maturation (IVM) and chemical activation. Initially, we assessed the IVM rates, cumulus-oocyte complex (COC) quality, and oocyte morphometry in the absence or presence of epidermal growth factor (EGF). There was no difference between the COCs matured in absence or presence of EGF for the expansion of cumulus cells (97.6% ± 1.2 vs. 100% ± 0.0), presence of first polar body (65.9% ± 1.2 vs. 70.5% ± 1.8), nuclear status in second metaphase (62.5% ± 11.6 vs. 68.4% ± 4.9), cytoplasmic maturation (100.0% ± 0.7 vs. 75.0% ± 0.7), reactive oxygen species levels (0.5 ± 0.2 vs. 0.3 ± 0.1), and mitochondrial membrane potential (1.1 ± 0.2 vs. 1.1 ± 0.1). However, the zona pellucida thickness of matured COCs was reduced in the presence of EGF. Thus, the EGF group was used for further experiments. The oocytes were artificially activated with ionomycin and four secondary activator combinations [6-dimethylaminopurine (6D), 6D and cytochalasin B (6D + CB), cycloheximide (CHX), and CHX and CB (CHX + CB)]. The effect of immature COCs based on cumulus cell layers and cytoplasm homogeneity (GI and GII or GIII COCs) on embryonic development and quality was evaluated. There was no difference in the cleavage rates among the groups of secondary activators. The cleavage rates of embryos derived from GI/GII and GIII COCs were greater than 72.2% and 25.0%, respectively. Moreover, treatment with CHX showed a reduction in the cleavage rate of embryos derived from GIII COCs when compared to the cleavage rate of embryos derived from GI/GII COCs (P < 0.05). Nevertheless, higher rates of blastocyst/total GI and GII COCs were observed in the 6D group (27.6% ± 0.3) compared to CHX group (6.9% ± 0.3). Additionally, only 6D treatment resulted in the production of embryos derived from GIII COCs (25.0% ± 0.2). The percentage of the ICM/total cell ratio was also greater in blastocysts derived from 6D (42.5% ± 19.0), 6D + CB (37.9% ± 21.9), and CHX + CB (43.8% ± 19.6) groups when compared to CHX (3.6% ± 0.1) group. Thus, the combination of ionomycin and 6D could produce collared peccary embryos by activation of both GI/GII COCs and GIII COCs. These optimized IVM conditions using EGF and chemical activation using ionomycin and 6D in collared peccaries form the first steps for establishing ARTs to conserve this species.

INFLUÊNCIA DO CORPO LÚTEO SOBRE A RECUPERAÇÃO DE OÓCITOS IMATUROS BOVINOS DERIVADOS DE FÊMEAS POST-MORTEM

O objetivo do presente trabalho foi avaliar a influência do corpo lúteo (CL), glândula endócrina temporária presente nos ovários, sobre a recuperação de oócitos imaturos bovinos derivados de ovários de fêmeas post-mortem. Para tanto, as seguintes comparações foram realizadas: fêmeas não prenhes com CL vs. fêmeas não prenhes sem CL; fêmeas prenhes com CL vs. fêmeas não prenhes com CL; e ovário com CL vs. ovário sem CL. Assim, ovários foram obtidos em abatedouro e os oócitos recuperados por aspiração folicular. A qualidade oocitária foi avaliada por morfologia convencional e ensaio de azul cresil brilhante (ACB), sendo quantificados oócitos viáveis e não viáveis para cada técnica. Todos os dados foram analisados pelo teste de Fisher (P<0,05). Assim, avaliando fêmeas ou ovários com ou sem CL, nenhuma diferença foi observada nos parâmetros avaliados. Contudo, um maior percentual de oócitos viáveis por morfologia foi obtido de fêmeas prenhes com CL, quando comparado às fêmeas não prenhes com CL. Em conclusão, pode-se afirmar que parâmetros de recuperação e qualidade oocitária não são afetados pela presença de CL, exceto em doadoras prenhes que apresentaram oócitos de melhor qualidade.