Optimizing semen cryopreservation in Calomys laucha: a step forward in rodent reproductive research

BACKGROUND

Examining semen cryopreservation in Calomys laucha offers valuable insights for reproductive research and species conservation.

OBJECTIVE

To determine the most effective sugar for the cryopreservation of C. laucha semen.

MATERIALS AND METHODS

Using 36 epididymides from C. laucha, semen samples were diluted in a 3% skimmed milk medium supplemented with one of four sugars (glucose, fructose, lactose, or sucrose) at a concentration of 0.3 M. These mixtures underwent a conditioning phase at 37 degree C for 10 min, cooled to -80 degree C for another 10 min, and were subsequently stored in liquid nitrogen.

RESULTS

Upon thawing, samples treated with lactose and glucose solutions show superior sperm motility, achieving 8.2% and 10.0% respectively, in contrast to the fructose (2.0%) and sucrose (4.1%) mixtures. Furthermore, samples preserved in glucose registered the highest sperm penetration rates, reaching 44.9%.

CONCLUSION

Our findings suggest that a cryopreservation medium containing 0.3 M glucose can contribute to the safeguarding C. laucha rodent semen. https://doi.org/10.54680/fr24210110612.

Ethanol, Carnoy, and paraformaldehyde as fixative solutions for histological evaluation of preantral follicles in equine ovarian tissue

The most adequate fixative solution for equine ovarian tissue is still to be determined as a tool to evaluate the improvement of methodological studies in assisted reproductive techniques and fertility preservation. This study aimed to evaluate a short-time ethanol 70% (ST-EtOH, 45 min) exposure as an alternative fixative compared with two classically fixatives [Carnoy's (CAR) solution and paraformaldehyde 4% (PFA)] at different fixation times (6 h, 12 h). The end points evaluated were morphology and classes of preantral follicles, follicular and stromal cell densities, and follicular and oocyte nuclear diameters in equine ovarian tissue. Ovaries (n = 6) from ovariectomized young mares were fragmented (3 × 3 × 1 mm; 20 fragments/ovary) and fixed in the tested treatments. Overall, a total of 11,661 preantral follicles were evaluated in 1444 histological slides. The ST-EtOH similarly preserved the preantral follicle morphometry and stromal cell density compared to the PFA fixative, regardless of the exposure time. Nonetheless, the CAR fixative solution had the greatest percentage of normal preantral follicles and the highest stromal cell density among all treatments. In conclusion, Carnoy's solution must be preferred compared with ST-EtOH and PFA fixatives for studies concerning the cellular morphology of equine ovarian tissue. Moreover, ST-EtOH fixative is a good alternative for equine ovarian tissue when a quick histological evaluation is required instead of more time-consuming and expensive techniques. Additional studies concerning the impact of different fixatives on the ultrastructure of cellular populations and their compatibility with IHC and molecular techniques in equine ovarian tissue are warranted.

Freezing of equine semen is influenced by exposure time and concentration of the cryoprotectant glycerol

BACKGROUND

Glycerol is a cryoprotectant widely used in the freezing of mammalian semen, but no study has demonstrated its optimum concentration and the appropriate exposure time for equine species.

OBJECTIVE

To demonstrate that the exposure time (15, 30, 45, 60, 75 and 90 min) versus concentration (2, 3, 4 and 5%) of the cryoprotectant glycerol influences the freezing success of equine semen.

MATERIALS AND METHODS

The ejaculate of 12 stallions were frozen in different glycerol concentrations following different exposure times. The thawed sperm was evaluated for kinetic parameters using a Computer Assisted Semen Analysis (CASA) system and cell feature parameters were assessed by flow cytometry.

RESULTS

Considering the total and progressive motility of the spermatozoa, we concluded that protocols using 5% glycerol for 15 and 30 min exposure, 4% glycerol for 45 min exposure and 3% glycerol for 90 min exposure generated the best results.

CONCLUSION

We suggest the use of any of these protocols for a better cryopreservation of equine semen. Doi: 10.54680/fr23410110412.

Exposure to salinity induces oxidative damage and changes in the expression of genes related to appetite regulation in Nile tilapia (Oreochromis niloticus)

Variations in water salinity and other extrinsic factors have been shown to induce changes in feeding rhythms and growth in fish. However, it is unknown whether appetite-related hormones mediate these changes in Nile tilapia (Oreochromis niloticus), an important species for aquaculture in several countries. This study aimed to evaluate the expression of genes responsible for appetite regulation and genes related to metabolic and physiological changes in tilapia exposed to different salinities. Moreover, the study proposed to sequence and to characterize the cart, cck, and pyy genes, and to quantify their expression in the brain and intestine of the fish by quantitative polymerase chain reaction (qPCR). The animals were exposed to three salinities: 0, 6, and 12 parts per thousand (ppt) of salt for 21 days. Furthermore, lipid peroxidation, reactive oxygen species, DNA damage, and membrane fluidity in blood cells were quantified by flow cytometry. The results indicated an increased expression of cart, pyy, and cck and a decreased expression of npy in the brain, and the same with cck and npy in the intestine of fish treated with 12 ppt. This modulation and other adaptive responses may have contributed to the decrease in weight gain, specific growth rate, and final weight. In addition, we showed oxidative damage in blood cells resulting from increasing salinity. These results provide essential data on O. niloticus when exposed to high salinities that have never been described before and generate knowledge necessary for developing biotechnologies that may help improve the production of economically important farmed fish.

Trehalose in extenders for cryopreservation of Tambaqui (Colossoma macropomum) sperm

BACKGROUND

Sugars may act as either energy substrates or non-penetrating cryoprotectants.

OBJECTIVE

Inclusion of non-penetrating trehalose was tested in extenders for the cryopreservation of Tambaqui (Colossoma macropomum) sperm.

MATERIALS AND METHODS

Sperm was extended 1/9 (v/v) in Beltsville Thawing Solution (BTS) with 10% DMSO (control) or 50, 100, 150 and 200 mM trehalose without 10% DMSO. Post-thawed sperm quality was evaluated, including fertilization and hatching rates, sperm motility, motility period and viability, integrity of sperm membrane and DNA, and mitochondrial functionality.

RESULTS

Extenders with 100 - 150 mM trehalose achieved fertilization and hatching rates similar to those of the 10% DMSO-treated sperm samples. Trehalose at 100 and 150 mM provides better protection than 10% DMSO treatment for sperm motility, viability, DNA integrity and mitochondrial functionality. Fertilization and hatching rates were highly correlated (r = 0.95, P < 0.001).

CONCLUSION

The addition of 100 - 150 mM trehalose in extender can replace 10% DMSO for the cryopreservation of C. macropomum sperm. doi.org/10.54680/fr22510110312.

Chronic cold exposure modulates genes related to feeding and immune system in Nile tilapia (Oreochromis niloticus)

Nile tilapia is the fourth most produced species in the global aquiculture panorama. This species requires water temperatures higher than 16 °C to grow and survive, and so, little is known about the effects of low temperatures on genes related to food intake and inflammatory responses. This study brought insights about the modulation of genes in different tissues of Nile tilapia chronically exposed to low temperatures. Thus, sixty animals were divided in two experimental groups: a control group in which the animals remained at the optimum temperature of 24 °C; and an exposed to cold group, in which a decrease in the water temperature was applied until reaching 15 °C. These conditions were maintained for 28 days. Blood samples were collected for flow cytometry analysis, while brain, spleen, liver, and kidney tissues were collected for total RNA extraction, followed by quantitative PCR (RT-qPCR). For genes related to feeding process pathway, it was observed an upregulation in pyy and a downregulation of npy and cart gene expression. Also, pro-inflammatory cytokine genes were modulated in the spleen, kidney and liver with a higher expression of il-1b and tnfα and a reduction in the il-8 and nf-κβ gene expressions in the group exposed to 15 °C. The fish exposed to cold presented higher serum cortisol levels than the ones from control group. The blood cell analysis showed a lower level of membrane fluidity and a higher DNA fragmentation and cell disruption in the group exposed to cold. These findings suggest an important effect of a stressful situation in the tilapia organism due to cold exposure. This study brings insights on tilapia wellbeing under low temperature stress. It can be a first step to understanding the appropriate way to cope with cold impacts on aquaculture.

Acute exposition to Roundup Transorb® induces systemic oxidative stress and alterations in the expression of newly sequenced genes in silverside fish (Odontesthes humensis)

Roundup Transorb® (RDT) is a glyphosate-based herbicide commonly used in agricultural practices worldwide. This herbicide exerts negative effects on the aquatic ecosystem and affects bioenergetic and detoxification pathways, oxidative stress, and cell damage in marine organisms. These effects might also occur at the transcriptional level; however, the expression of genes associated with oxidative stress has not been studied well. Odontesthes humensis is a native Brazilian aquatic species naturally distributed in the habitats affected by pesticides, including Roundup Transorb® (RDT). This study evaluated the toxic effects of short-term exposure to RDT on O. humensis. Moreover, the genes related to oxidative stress were sequenced and characterized, and their expressions in the gills, hepatopancreas, kidneys, and brain of the fish were quantified by quantitative reverse transcription-polymerase chain reaction. The animals were exposed to two environmentally relevant concentrations of RDT (2.07 and 3.68 mg L^-1) for 24 h. Lipid peroxidation, reactive oxygen species (ROS), DNA damage, and apoptosis in erythrocytes were quantified by flow cytometry. The expression of the target genes was modulated in most tissues in the presence of the highest tested concentration of RDT. In erythrocytes, the levels of lipid peroxidation, ROS, and DNA damage were increased in the presence of both the concentrations of RDT, whereas cell apoptosis was increased in the group exposed to 3.68 mg L^-1 RDT. In conclusion, acute exposure to RDT caused oxidative stress in the fish, induced negative effects on cells, and modulated the expression of genes related to the enzymatic antioxidant system in O. humensis.

Genome-wide association and genomic prediction for scrotal circumference in Hereford and Braford bulls

Scrotal circumference (SC) is widely used as a selection criterion for bulls in breeding programs, since it is easily assessed and correlated with several desirable reproductive traits. The objectives of this study were: to perform a genome-wide association study (GWAS) to identify genomic regions associated with SC adjusted for age (SCa) and for both age and weight (SCaw); to select Tag SNPs from GWAS to construct low-density panel for genomic prediction; and to compare the prediction accuracy of the SC through different methods for Braford and Hereford bulls from the same genetic breeding program. Data of SC from 18,172 bulls (30.4 ± 3.7 cm) and of genotypes from 131 sires and 3,545 animals were used. From GWAS, the top 1% of 1-Mb windows were observed on chromosome (BTA) 2, 20, 7, 8, 15, 3, 16, 27, 6 and 8 for SCa and on BTA 8, 15, 16, 21, 19, 2, 6, 5 and 10 for SCaw, representing 17.4% and 18.8% of the additive genetic variance of SCa and SCaw, respectively. The MeSH analysis was able to translate genomic information providing biological meanings of more specific gene functions related to the SCa and SCaw. The genomic enhancement methods, especially single step GBLUP, that combined phenotype and pedigree data with direct genomic values generated gains in accuracy in relation to pedigree BLUP, suggesting that genomic predictions should be applied to improve genetic gain and to narrow the generation interval compared to traditional methods. The proposed Tag-SNP panels may be useful for lower-cost commercial genomic prediction applications in the future, when the number of bulls in the reference population increases for SC in Hereford and Braford breeds.

Komagataella pastoris KM71H modulates neuroimmune and oxidative stress parameters in animal models of depression: A proposal for a new probiotic with antidepressant-like effect

Many studies have suggested that imbalance of the gut microbial composition leads to an increase in pro-inflammatory cytokines and promotes oxidative stress, and this are directly associated with neuropsychiatric disorders, including major depressive disorder (MDD). Clinical data indicated that the probiotics have positive impacts on the central nervous system and thus may have a key role to treatment of MDD. This study examined the benefits of administration of Komagataella pastoris KM71H (8 log UFC·g^-1/animal, intragastric route) in attenuating behavioral, neurochemical, and neuroendocrine changes in animal models of depressive-like behavior induced by repeated restraint stress and lipopolysaccharide (0.83 mg/kg). We demonstrated that pretreatment of mice with this yeast prevented depression-like behavior induced by stress and an inflammatory challenge in mice. We believe that this effect is due to modulation of the permeability of the blood-brain barrier, restoration in the mRNA levels of the Nuclear factor kappa B, Interleukin 1β, Interferon γ, and Indoleamine 2 3-dioxygenase, and prevention of oxidative stress in the prefrontal cortices, hippocampi, and intestine of mice and of the decrease the plasma corticosterone levels. Thus, we conclude that K. pastoris KM71H has properties for a new proposal of probiotic with antidepressant-like effect, arising as a promising therapeutic strategy for MDD.

High-speed centrifugation of extender of freeze-thaw boar semen

In semen cryopreservation, egg yolk is still widely used as a non-penetrating cryoprotectant. Much has been developed in the search for alternatives for this biological product. This work aimed to evaluate the processed egg yolk through ultracentrifugation and/or sonication in the cryopreservation of swine semen. Twenty-seven semen doses were purchased from a commercial boar stud and processed for cryopreservation using egg yolk lactose 11% (control) extender, processed using two different methods: high-speed centrifugation and sonication. Then, they were submitted to freeze-thawing protocol and were assessed for kinematic and cell structural parameters. Samples in which extenders underwent centrifugation had better results in velocity parameters, meanwhile those that only sonication was performed had poorest results in this parameter. The preservation of the membrane and mitochondria structure had better results when the diluent was only centrifuged in comparison with the other treatments. Therefore, centrifugation of extender containing egg yolk is important for better cryopreservation of swine semen.

Dimethylacetamide in Rooster Semen Cryopreservation

BACKGROUND

Sperm cryopreservation of cockerels is a major challenge, and so far there is no adequate information to enable commercial use of frozen semen.

OBJECTIVE

To test the toxicity of dimethylacetamide (DMA).

MATERIALS AND METHODS

DMA was added at 3%, 6%, 9% and 12% to the freezing diluent, and maintained for equilibration with the semen sample for 1 min, 3 min, 5 min, 7 min and 9 min prior to freezing. Thawed semen was evaluated for kinetic characteristics by computer-assisted semen analysis (CASA) and for structural and functional properties by flow cytometry (plasma membrane rupture, mitochondrial functionality and plasma membrane functionality).

RESULTS AND CONCLUSION

The addition of 6% DMA for 3-min equilibration resulted in the highest total and progressive motility, 42.0% and 36.9%, respectively. The point of intersection between a good protection and low plasma membrane rupture was obtained with the addition of 6% of DMA for 3-min equilibration with the rooster semen.

Protein profile as a quality indicator of cryopreserved semen from Tambaqui Colossoma macropomum (Cuvier, 1818)

The aim of this study was to evaluate the association between proteins in the seminal plasma of tambaqui Colossoma macropomum (Cuvier, 1818) with seminal quality indicators after thawing. The semen was cryopreserved with a dilution based on BTS with 8% DMSO. A 200 µL sample of semen from each animal was diluted in 800 µL BTS, centrifuged at 800 rpm, and the supernatant was cryopreserved to further analyze of the protein profile of seminal plasma through one-dimensional electrophoresis (SDS-PAGE). After 15 days of cryopreservation, a cryopreserved semen straw was thawed to analyze both qualitative and quantitative parameters. When considering all collections, the SDS-PAGE identified 15 protein bands in the seminal plasma of tambaqui. When the interaction (presence or absence) between proteins observed in the seminal plasma and the post thawed spermatic parameters was evaluated, we observed a great influence of the presence of proteins on spermatic quality. A greater (P<0.05) fertilization rate was observed with the presence of proteins 12, 34, 44, 85, and 90 kDa. Proteins in seminal plasma of tambaqui influenced the spermatic quality after thawing, and thus, they can be utilized as an indicator of sperm quality, especially the proteins with a molecular weight ≤ 50 kDa.

Capillary electroporation affects the expression of miRNA-122-5p from bull sperm cells

Sperm-mediated gene transfer (SMGT) has a potential application in the generation of transgenic animals. Capillary electroporation consists of the application of electrical pulses, resulting in an increased transfection rate. Little is known about the impacts of the transfection of exogenous DNA on sperm epigenetics. MicroRNAs are epigenetic factors that are related to sperm motility. MiRNA-122-5p regulates genes that influence motility, and consequently, the fertilizing potential of sperm. Therefore, we aimed at identifying whether epigenetic factors such as microRNAs could be altered after DNA transfection, using the capillary electroporation technique. In this study, bull sperm was electroporated using voltages of 600 V, 1500 V, and 0 V (control group), with or without exogenous DNA. Parameters of sperm quality were analyzed using CASA and flow cytometry, and expression of the miRNA-122-5p was analyzed using RT-qPCR. It was observed that electroporation increased the internalization of exogenous DNA (P < 0.05), but did not impair the mitochondrial activity (P > 0.05). It reduced sperm motility (P < 0.05). The expression of miRNA-122-5p was upregulated in sperm electroporated at 1500 V, and the presence of exogenous DNA did not affect its expression. Thus, we can conclude that electroporation influences the expression of miRNA-122-5p from bull sperm cells.

Efficiency and cell viability implications using tip type electroporation in zebrafish sperm cells

Sperm-mediated gene transfer (SMGT) has a potential use for zebrafish transgenesis. However, transfection into fish sperm cells still needs to be improved. The objective was to demonstrate the feasibility of tip type electroporation in zebrafish sperm, showing a protocol that provide high transfection efficiency, with minimal side-effects. Sperm was transfected with a Cy3-labelled DNA using tip type electroporation with voltages ranging from 500 to 1500 V. Sperm kinetics parameters were assessed using Computer Assisted Semen Analysis (CASA) and cell integrity, reactive oxygen species (ROS), mitochondrial functionality and transfection rate were evaluated by flow cytometry. The transfection rates were positively affected by tip type electroporation, reaching 64.9% ± 3.6 in the lowest voltage used (500 V) and 86.6% ± 1.9 in the highest (1500 V). The percentage of overall motile sperm in the electrotransfected samples was found to decrease with increasing field strength (P < 0.05). Increase in the sperm damaged plasma membrane was observed with increasing field strength (P < 0.05). ROS and sperm mitochondrial functionality did not present a negative response after the electroporation (P > 0.05). Overall results indicate that tip type electroporation enhances the internalization of exogenous DNA into zebrafish sperm cells with minimal harmful effects to sperm cells.

Liquid Storage of Geophagus brasiliensis semen in the Presence of Different Extenders

BACKGROUND

In order to preserve the genetic diversity of cichlid fish in gene banks, it is necessary to use certain extenders to maintain the integrity of spermatozoa cells during cooling.

OBJECTIVE

To evaluate the effects of different extenders on the quality parameters of cooled semen of Geophagus brasiliensis.

MATERIALS AND METHODS

Semen samples were collected from seven adult fish and diluted with five extenders: Beltsville Thawing Solution (BTS™), Hanks' Balanced Salt Solution (HBSS), Tris-glucose, Ginsburg's Fish Ringers, and Phosphate buffered Saline. All parameters were evaluated in fresh semen samples and after cooling at 4°C at 0, 24, 48, and 96 h to evaluate cell viability (membrane integrity, DNA, and mitochondrial functionality) and motility rate and weather motility.

RESULTS

The BTS and Tris-glucose resulted in the best outcomes (P<0.05) in terms of membrane integrity assessments (35.1% and 30.9%, respectively), DNA integrity (71.6%; 75.7%), mitochondrial function (26.9%; 28.0%) and motility rate (8.6%; 8.6%), respectively, for semen cooled to 4°C for 96 h. However, the 48-h period motility after cooling in BTS was superior to all other treatments.

CONCLUSION

BTS and Tris-glucose can be considered as the best extenders for the cold storage of Geophagus brasiliensis spermatozoa.

Transfection of exogenous DNA complexed to cationic dendrimer induces alterations of bovine sperm microRNAome

MicroRNAs have been hypothesized to be involved in the regulation of male fertility potential. The primary aim of our study was to demonstrate the effects of transfection with dendrimer nanostructure on the parameters of bovine sperm quality and to investigate whether the microRNA profile could be disturbed after cationic dendrimer-mediated exogenous DNA transfection of bovine spermatozoa. The binding of exogenous DNA was significantly increased when dendrimer-based transfection was implemented. However, cationic dendrimer transfection induced detrimental changes in the kinetics and sperm quality parameters, such as membrane integrity, acrosome reaction, and mitochondrial membrane potential, when compared to the control group. Sperm microRNA sequencing revealed 218 known and 106 novel microRNAs in the sperm samples, among which nine were dysregulated after transfection (one was upregulated and eight were downregulated), in comparison to the non-transfected sperm. All the dysregulated microRNAs were related to sperm quality and embryonic development. These results suggest that the transfection process using the dendrimer nanostructure has an impact on the quality and microRNA profile of bovine sperm.

Exogenous ATP in the Cryopreservation of Brycon orbignyanus Spermatozoa

BACKGROUND

ATP exogenous (ATPe) has been used successfully in improving motility and fertility for many animal species. However this has not yet been tested on Brycon orbignyamus.

OBJECTIVE

The objective of this study was to evaluate the use of ATPe for the cryopreservation of sperm from B. orbignyamus.

MATERIALS AND METHODS

The ATPe concentrations tested were 1.0 µM, 5.0 µM and 10 µM combined with Beltsville Thawing Solution^TM extender and dimethylformamide at 7.5%. The sperm were frozen in a nitrogen vapour vessel and stored in liquid nitrogen at -196 ºC. The parameters of viability post-thawing were evaluated using CASA, and flow cytometer.

RESULTS

The ATPe did not promote improvements in spermatic kinetics, and in the higher concentrations caused a worsening in these parameters. Also there was loss of mitochondrial functionality and greater cellular disruption with the concentration of 10 μM.

CONCLUSION

We do not recommend the addition of ATP for cryopreserving B. orbignyamus.

Effect of Amide on Semen Cryopreservation of Curimba (Prochilodus lineatus)

BACKGROUND

The low molecular weight and high cellular permeability of amides make them suitable for use as penetrative cryoprotectants for sperm cells.

OBJECTIVE

This study aims to evaluate the effect of dimethylformamide (DMF) and dimethylacetamide (DMA) on sperm cryopreservation of Curimba (Prochilodus lineatus).

MATERIALS AND METHODS

Semen samples were diluted in media containing cryoprotectants [DMF, DMA and dimethyl sulfoxide (DMSO)]. Parameters of motility, membrane integrity, DNA integrity, mitochondrial functionality, viability and fertility were assessed upon thawing.

RESULTS

As compared to the 10% DMSO, DMA at 5% and DMF at 2% obtained the best results for the integrity of membrane, DNA and mitochondria; the motility parameters were best in the 2% and 5% DMF treatments. The best fertilization rates were demonstrated in 2%, 5%, and 8% DMF treatment groups.

CONCLUSION

DMF at 2%, 5%, and 8% provided the best results for both in vitro and in vivo assessments, and can efficiently cryopreserve semen of Prochilodus lineatus.

Effects of Bisphenol A on redox balance in red blood and sperm cells and spermatic quality in zebrafish Danio rerio

Bisphenol-A (BPA) is a potential endocrine disruptor besides being associated with oxidative damage in several vertebrate classes. In the present study we investigated oxidative effects in erythrocytes and sperm cells as well as spermatic quality in Danio rerio exposed to 14 days at BPA concentrations of 2, 10 and 100 μg/L. Organelles structure, reactive species of oxygen (ROS) and lipoperoxidation (LPO) on erythrocytes and sperm cells were measured by flow cytometry and spermatic parameters were analyzed by the computer-assisted sperm analysis (CASA) system. For both cell types, when compared with control BPA treatment induced a significant increase in ROS and LPO production causing the membrane fluidity disorder, loss of membrane integrity and mitochondrial functionality. Furthermore, it was found a significant increase in DNA fragmentation in erythrocytes of zebrafish BPA exposed. Regarding the spermatic quality, results showed lower sperm motility in animals exposed to BPA, and alterations on velocity parameters of spermatozoa. Thus, the present study concludes that BPA affects the oxidative balance of both cell types, and that can directly affects the reproductive success of the adult Danio rerio. The sensitivity of erythrocytes to oxidative damage induced by BPA was similar to sperm cells, indicating a potential use of blood cells as indicators of oxidative damage present in fish sperm.

Use of trehalose in the semen cryopreservation of Amazonian catfish Leiarius marmoratus

The current study assessed a semen cryopreservation protocol in the Amazonian catfish Leiarius marmoratus, a freshwater fish, of rheophilic behavior, and of great importance for Brazilian fish farming. Eight males (n = 8) were stripped and the semen was cryopreserved if total motility in fresh semen was higher than 80%. The external cryoprotectant Trehalose was then diluted in Beltsvile Thawing Solution (BTS) extender in the following concentrations: 50, 100, 150, and 200 mM. Semen samples were diluted in the media (1:9 v/v) being tested, then frozen in a container with nitrogen vapor (dryshipper), and stored in liquid nitrogen at -196 °C. Motility parameters assessed post-thawing were performed by CASA-system and sperm cell integrity analyses (membrane integrity, DNA integrity, and mitochondrial function) were performed through fluorescence microscopy. As a result, no significant statistical difference was observed between treatments, independently of Trehalose concentrations tested in the following post-thawing analysis: membrane integrity, DNA integrity, mitochondrial functionality, and sperm motility duration. As of total and progressive motilities, the treatment containing 50 mM trehalose (15.6 and 9.5%, respectively), exhibited inferior results when compared to treatments with 150 mM (22.9 and 17.7%, respectively) and 200 mM (31.4 and 26.3%, respectively) trehalose concentrations (P < 0.05); however, it did not differ from the treatment with 100 mM trehalose (18.6 and 15.3%, respectively). Therefore, treatments with trehalose at higher concentrations exhibited superior results when compared to other treatments in in vitro motility parameters for L. marmoratus.

Association Between DMSO and Sugars in the Sperm Cryopreservation of Pacu

　　BACKGROUND: The cryopreservation protocol that has been developed exclusively for the preservation of the sperm of the species different.

OBJECTIVE

this study was to evaluate the effect of the association of 10% DMSO with trehalose, raffinose, sucrose and lactose concentrations on the sperm cells of Piaractus mesopotamicus.

MATERIALS AND METHODS

Sperms were collected from the animals through abdominal massage. The samples were diluted in the Beltsville Thawing Solution without different concentrations of other sugars (test conditions). Sixty days after the cryopreservation, cell movement analysis was performed using CASA.

RESULTS

The results revealed that the parameters for total motility and motility period were superior when 100mM raffinose (P <0.05). The lateral displacement of the head was observed to be improved was 100mM lactose, 150mM sucrose and 150mM raffinose (P <0.05) as compared to treatment wherein lactose (0mM) was omitted.

CONCLUSION

the results of our study indicated that the ideal parameters for cryopreservation, were obtained when the cryopreservation fluid contained 100mM raffinose in association with DMSO.

Evaluation of sperm quality of Erythrolamprus poecilogyrus sublineatus (Cope, 1860) (Serpentes, Dipsadidae)

Erythrolamprus poecilogyrus sublineatus (Cope, 1860), is a species widely distributed in the Pampa Domain, occurring in Rio Grande do Sul, Argentina and Uruguay, mainlyin the pampa region. In the coastal region of southern Brazil this is serpent is considered one of the most abundant. The purpose of the present study is to describe the techniques of sperm evaluation in vitro for E. poecilogyrus sublineatus in the coastal plain of Rio Grande do Sul, Brazil. After laparatomy the efferent vases were collected and the semen was diluted in 1ml Beltsville Thawing Solution. The characteristics of motility, membrane integrity, mitochondria, acrosome, DNA, cell viability and cellular functionality were evaluated. Fluorescent probes were used for the evaluation of sperm structure in epifluorescence microscope. With the techniques described, it was possible to identify intact and injured cells, enabling the determination of cell characteristics for the spring season (October and November). It was observed in the analyses that 80% of sperm cells were mobile and that 84.1 ± 8.0% of sperm membranes were intact. The standards found were of 48 ± 13.8% of intact acrosome, 73.6 ± 6.0 of perfect DNA and of 91.8 ± 4.0 of functional mitochondria. Thus, these values from the sperm analysis can be used as standards for the species Erythrolamprus poecilogyrus sublineatus.

Cooling strategies for brazilian flounder Paralichthys orbignyanus embryos

BACKGROUND

Paralichthys orbignyanus is the species of the greatest potential for marine and estuarine fish farming in southern Brazil. Consequently, embryo cryopreservation becomes an important tool for increasing their production.

OBJECTIVE

To evaluate the effects of cooling protocols on the viability of embryos of P. orbignyanus at two stages of development (neurula and early differentiation of the tail).

MATERIALS AND METHODS

Control embryos were maintained at 23 degree C and treated embryos were cooled to 15 degree C, 10 degree C and 5 degree C at rapid, moderate and slow cooling rates. Then embryos were maintained at these different temperatures for 30, 60 and 90 min and the loss of viability assessed as hatching rates (HR) and morphologically normal larvae (MNL).

RESULTS

The average HR for embryos following cooling was higher for those at the tail stage compared to the neurula stage (P<0.05). In both stages there was no statistical difference between the HR of control embryos and those exposed to rapid cooling. Also for tail stage embryos, there was no difference between MNL of control and rapidly cooled embryos.

CONCLUSION

As first steps in the development of cryopreservation methods for P. orbignyanus embryos, the use of a rapid cooling and holding at 5 degree C for 30 min are recommended.

Antioxidant Effect of Xanthan Gum on Ram Sperm after Freezing and Thawing

BACKGROUND

Xanthan gum is used as thickener in media to preserve food products, having cryoprotectant and antioxidant properties that may be relevant for sperm cryopreservation.

OBJECTIVE

To evaluate the effects of adding xanthan gum to freezing extenders on post-thawing quality and oxidant activity of ram sperm.

METHODS

Ejaculates from seven rams extended TRIS-egg yolk-glycerol were split in three treatments including xanthan gum (0.15%; 0.20%; and 0.25%) and a control with no xanthan gum.

RESULTS

After thawing, motility and production of reactive oxygen species (ROS) with 0.20% and 0.25% xanthan gum were lower than for the control (P < 0.05), but mitochondrial functionality and integrity of membrane, acrosome and DNA did not differ (P > 0.05). Xanthan gum at 0.20% and 0.25% may be an efficient antioxidant for frozen-thawed ram sperm, due to the reduction in ROS production.

Quercetin in equine frozen semen

　　BACKGROUND: Supplementation of sperm diluents to reduce the damage caused by the freeze-thaw cycle is broadly used in equine semen cryopreservation.

OBJECTIVE

The present study aimed at determining the most appropriate quercetin supplementation in equine freezing extender.

MATERIALS AND METHODS

Quercetin at four different concentrations (0.25, 0.5, 0.75 or 1 mM) was added in the sperm freezing diluent before the freeze-thaw cycle. The spermatozoa population was analyzed by flow cytometry and a statistical analysis was conducted to detect significant differences between control and treated samples.

RESULTS

The statistical analysis did not reveal any significant modification of seminal parameters.

CONCLUSION

Within the concentrations tested, quercetin supplementation in equine freezing extender did not affect progressive motility, mitochondrial functionality, acrosome reaction, membrane integrity or DNA fragmentation index in post-thaw equine semen.

EFFECT OF SOLID MEDIUM DURING COOLED STORAGE ON STALLION SPERM PARAMETERS

BACKGROUND

Solid storage medium prevents cellular sedimentation, reduces metabolic demand via limiting movement, and avoids the modification of an extender composition in the sedimentary microenvironment. It has been proven to prolong spermatozoa viability in mammalians.

OBJECTIVE

This experiment aims to evaluate the effect of cool storage in solid phase extender on stallion sperms.

MATERIALS AND METHODS

Semen was collected from 10 Crioulo stallions (n=30) and submitted to treatments: control group (semen extender) and groups with gelatin addition in different concentrations (semen extender + 1%, 2% and 3%). Seminal analyses included motility, mitochondrial functionality, plasma membrane integrity, DNA and acrosome at 0; 24; 48 and 72 hours during cooled storage at 5 degree C.

RESULTS

Motility, mitochondrial functionality, plasma membrane and acrosome integrity declined during storage time, with no statistical difference between treatments. DNA integrity did not significantly change during storage period.

CONCLUSION

Solid medium was not harmful and did not improved stallion sperm parameters during cooled storage.

Effect of egg yolk plasma on dog sperm cryopreservation

This study evaluated the quality of frozen-thawed dog spermatozoon after the inclusion of egg yolk plasma (EYP) instead of whole egg yolk (EY) in the cryopreservation extender and after distinct periods of exposure to EYP. Seven mongrel dogs were used as sperm donors, and EYP was obtained by centrifugation. In Experiment 1, post-thawing sperm motility (MOT) and integrity of membrane (INT) and acrosome (ACR) were superior for spermatozoon extended with 20% EYP T2 than with 20% EY (P < 0.05), although normal sperm morphology (MOR) did not differ (P > 0.05). In Experiment 2, after ejaculates extended with 20% EYP were cooled at 5°C for 2, 6 and 10 h before freezing, MOT, INT and ACR were similar among periods (P > 0.05). Thus, dog spermatozoon extended with 20% EYP can be kept cooled for up to 10 h prior to freezing, achieving post-thawing quality greater than that obtained with the inclusion of EY in freezing extenders.

Influence of mineral, olive or sunflower oils on male reproductive parameters in vitro--the wild rodent Calomys laucha

The aim of this study was to evaluate the influence of oils on male reproductive parameters in Calomys laucha. Twenty-four animals were distributed into four groups and given the following substances by gavage: water, mineral oil, olive oil and sunflower oil. After 10 days of gavage, the animals were euthanised and the semen was collected from them for assessing acrosome integrity and carrying out in vitro penetration (IVP) test. Acrosome was significantly reduced (P < 0.05) for the vehicles in relation to control. In vitro penetration was reduced in all vehicles in relation to control, but only sunflower oil had statistically lower levels of reduction (P < 0.05). Oily vehicles are able to influence in vitro reproductive tests negatively, interfering in reproductive toxicological studies.

GH overexpression decreases spermatic parameters and reproductive success in two-years-old transgenic zebrafish males

Growth hormone (GH) transgenesis has been postulated as a biotechnological tool for improving growth performance in fish aquaculture. However, GH is implied in several other physiological processes, and transgenesis-induced GH excess could lead to unpredictable collateral effects, especially on reproductive traits. Here, we have used two-years-old transgenic zebrafish males to evaluate the effects of GH-transgenesis on spermatic parameters and reproductive success. Transgenic spermatozoa were analyzed in terms of motility, motility period, membrane integrity, mitochondrial functionality, DNA integrity, fertility and hatching rate. We have also performed histological analyses in gonad, in order to verify the presence of characteristic cell types from mature testes. The results obtained have shown that, even in transgenic testes present in all cells in normal mature gonads, a significant general decrease was observed in all spermatic and reproductive parameters analyzed. These outcomes raise concerns about the viability of GH-transgenesis appliance to aquaculture and the environmental risks at the light of Trojan gene hypothesis.