Proliferation and apoptosis dynamics of the normal canine mammary gland during the oestrous cycle evaluated by Ki-67 and Caspase-3 indexes.

Understanding the normal physiology of the canine mammary gland (CMG) is crucial, as it provides a foundational reference for understanding canine mammary neoplasms. The relation between the Proliferation Index (PI) indicated by Ki-67 expression, along with the Apoptotic Index (AI) determined through Caspase-3 expression during the oestrous cycle, is inadequately documented in existing literature. This study seeks to offer insights into the interplay between PI and AI in the CMG across oestrous cycle phases. An extensive investigation was conducted on a diverse case series of bitches (n = 18). Oestrous cycle stages were determined through vaginal cytology, histological examination of the reproductive tract and serum progesterone and oestradiol concentrations. The entire mammary chain was histologically examined, and proliferation and apoptosis were assessed via double immunohistochemistry employing anti-Ki-67 and Caspase-3 antibodies. PI and AI were evaluated through a systematic random sampling approach, counting a minimum of 200 cells for each cell type. There was a significantly higher PI during early dioestrus in all mammary gland components, with a greater proportion of positive cells observed in epithelial cells compared to stromal cells. The highest PI was detected in epithelial cells within the end buds. Significant differences were found in Ki-67 labelling across the cranial mammary glands. A positive and strong correlation was noted between progesterone concentration and PI in epithelial cells. The AI remained consistently low throughout the oestrous cycle, with few differences observed across histological components. Caspase-3 labelling displayed the highest positivity in caudal mammary pairs. A negative and moderate correlation was identified between progesterone concentration and AI in interlobular mesenchymal cells. This study highlights the influence of endocrine regulation on cell proliferation indices in mammary tissue, emphasizing the need to consider these hormonal variations in toxicopathological studies involving canine mammary gland.

Macro and microscopic characteristics of the placenta and its relationship with the weight and the Apgar score of canine neonates.

The placenta is the main organ of pregnancy and is directly related to the proper development of the fetus. The correlation among some placental measurements and their respective neonates is widely studied in the human species. However, the studies regarding bitches are still limited. Therefore, the aim of this work was to evaluate if there is a relationship between placental weight and volume and the weight of neonates at birth in the canine species, as well as its influence on their viability. In this work, 7 bitches, 18 neonates and their placentas were evaluated. The weight of the placentas was measured using an analytical balance and the volume was calculated by measuring the volume of water displaced after placing it in a container of water. The neonates were weighed and classified according to the Apgar score after birth. Samples from each placenta were fixed in formalin and embedded in paraffin, then placed on slides and stained in hematoxylin and eosin. From these samples, the microvascular density (MVD) was calculated, as well as the presence or absence of necrosis, calcification and haemorrhage, classified in scores from 0 to 2. Data were analyzed using Kendall's test. The mean weight of the placentas was 29.11 ± 11.06 g and the volume was 21.33 ± 10.65 cm³. The mean weight of the neonates was 282.94 ± 123.28 g and the Apgar score was 8.83 ± 2.06. The mean MVD of the placentas was 0.04 ± 0.01. A positive correlation was observed between birth weight and placental weight and volume. Placental weight also positively correlated with placental volume. Also, no significant correlation was found between MVD and alterations with placental weight and volume and with the weight and Apgar score of neonates. Among the microscopic changes, only necrosis showed a moderate correlation with placental weight and volume. It can be concluded that the placenta has an influence on the weight of neonates, which is essential for its development in intra and extrauterine life. However, more studies are required in the described species, to better elucidate these questions.

CA 15-3, CRP, and LDH correlates with prognostic parameters in canine mammary neoplasms.

The identification of putative prognostic factors in canine mammary neoplasms (CMNs) has been focused on tissue-specific biomarkers, but the serum biomarkers, including cancer antigen 15-3 (CA 15-3), c-reactive protein (CRP), and lactate dehydrogenase (LDH) have been demonstrated to display clinical application in cases of CMNs. The aim of the study was to evaluate the levels of these serum biomarkers and their association with well-established prognostic factors in CMNs. Samples from 15 female canines with CMNs and 15 clinically healthy ones were collected. The results were evaluated using the Tukey's, Pearson, or Spearman tests. The cut-off point, sensitivity, specificity, and area under curve (AUC) were evaluated using the receiver operating characteristic (ROC) curve analysis in a logistic regression model (P<0.05). The levels of CA 15-3, CRP and LDH were significantly higher in the serum of female dogs with CMNs compared to the healthy ones. Moreover, these factors were positively correlated with ulceration, tumor size, histopathological grade, metastatic lymph node, and clinical staging. Female dogs with CMNs were found to exhibit highest serum levels of CA 15-3, CRP, and LDH. Therefore, they can be applied to improve the efficacy of the diagnosis and prognostic evaluation in casas of CMNs.

Sperm quality and morphometry characterization of cryopreserved canine sperm in ACP-106c or TRIS.

Morphological sperm evaluation supported by the morphometry can be used in the determination of the seminal quality and in the investigation of potential extenders. Although there are studies comparing TRIS and ACP extenders, there are no comparative studies between them for the computerized assisted semen analysis (CASA), sperm viability, membrane functionality and sperm morphometry parameters of cryopreserved canine semen. Hence, we aimed to evaluate the effects of ACP-106c and TRIS on post-freezing canine sperm quality. Five dogs were submitted to semen collection twice with one-week interval. The semen was evaluated within the parameters: total motility, vigor, concentration, viability, plasma membrane functionality, morphology and morphometry. In the morphometric evaluation, the morphologically normal sperm was measured as: length, width, area and perimeter of the head and the midpiece, tail length and total length. The parameters of ellipticity, elongation, regularity and roughness were determined. Then, the semen was divided into two aliquots that were diluted in TRIS or ACP-106c, with the addition of egg yolk and glycerol. The diluted semen was refrigerated and frozen. The thawed samples were evaluated. Total motility, viability, sperm membrane functionality and normal morphology reduced after thawing in both extenders (morphology reduced from 89.60 ± 1.3% to 84.40 ± 1.8 and 84.60 ± 1.1% in TRIS and ACP-106c, respectively). However, it did not differ between TRIS and ACP-106c. In the ACP-106c the sperm head defects in cryopreserved semen were higher compared to fresh semen (P < 0.05). For all the morphometric parameters evaluated, there were no differences between fresh and cryopreserved samples (3.70 ± 0.4% vs. 2.30 ± 0.5%). In kinetics, with an interval of one week statistical differences between the extenders were found only in the parameters ALH and LIN (P < 0.05). Regardless of the extender, there were no changes in the morphometric parameters of sperm after thawing.

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.

Canine and Feline Testicular Preservation.

The increased interest in breeding dogs and cats and their use as models for other canids and felids demand research to improve reproductive techniques. Among them, testicular cryopreservation stands out. Testicular cryopreservation enables the maintenance of reproductive capacity and allows the establishment of germplasm banks for several species of commercial value or at risk of extinction. Furthermore, it enables the transport of genetic material among different regions. It is noteworthy that this biotechnology represents the only possibility of preserving the fertility of prepubertal animals that have died, so it has great importance in the propagation of the genetic material of animals. The spermatogonia present in the testes can be cultivated in vitro and the sperm obtained can be used in artificial reproduction programs. Although advances have been achieved with the use of testicular fragments to obtain viable and functional germ cells, the establishment of protocols that can be used in clinical routine have not been concluded yet. The testicular cryopreservation process can be carried out through techniques such as slow freezing, fast freezing and vitrification. However, the protocols used for the canine and feline species are still in the experimental phase. Given the importance of the topic, the aim of this review is to draw a profile of the subject approaching the main works on testicular cryopreservation in dogs and cats.

Influence of different warming temperatures on the vitrified testicular fragments from pre-pubertal cat.

Testicular vitrification is an alternative to preserve the genetic material of pre-pubertal animals. However, there are few studies on post-vitrification warming. Hence, the aim was to compare the influence of different warming temperatures on vitrified testicular fragments from pre-pubertal cats. The testicles were fragmented and divided into a control group (non-vitrified) and vitrified, using an association between dimethylsulphoxide and glycerol. The vitrified fragments were warmed at 50, 55 and 60°C/5 s. Morphological and morphometric evaluations were carried out using classical histology. Afterwards, the mitochondrial activity was evaluated using Rhodamine 123. The data were expressed in mean and standard error. The differences were considered significant when p < .05. In the histomorphological analysis, the testicular fragment presented seminiferous tubules with poorly developed germinal epithelium, compatible with pre-pubertal animals. The group warmed at 50°C presented similar to the control regarding the maintenance of the integrity of the tubules and cells, without stromal rupture and lamina propria alteration, as well as regarding the maintenance of the junctions between the cells. The group warmed at 55°C showed reduction of the cell junctions, and the one warmed at 60°C had increased detachment of the basement membrane (p < .05). The warming caused a reduction in the tubular diameter inversely proportional and progressive to the increase in temperature, with the highest diameter in the control group and the lowest in the 60°C group. The control group showed a lower incidence of Rhodamine 123, followed in ascending order of the warmings at 55 and 60°C. The higher mitochondrial activity was obtained with 50°C, showing an increase of the metabolic cell function at this temperature. It was concluded that the testicular fragment of pre-pubertal cats presents a better preserved morphology, morphometry and viability when warmed at 50°C.

Long-term Preservation of Testicular Tissue Integrity and Viability Using Vitrification in the Endangered Black-Footed Ferret (Mustela Nigripes).

Systematic cryo-banking of semen and testicular tissues is critical to preserve the genetic value of recently deceased or neutered black-footed ferrets (BFFs). Specifically, recovering or producing mature sperm cells from vitrified-warmed issues offers additional options in assisted reproduction. This could, in turn, enhance the genetic management of this rare and endangered species over multiple generations. The objective of the study was to evaluate structural properties, DNA fragmentation, cell viability, and germ cell composition in vitrified testicular tissues from BFFs directly after warming or after warming plus a short in vitro culture period. Tissue biopsies from five adult BFFs were either kept fresh or vitrified with a standard protocol (using dimethylsulphoxide (DMSO) and glycerol) and warmed at 50 °C for 5 s. Some of the warmed samples were then cultured in vitro for 24 h. Fresh, warmed, and warmed/cultured tissues were analyzed using different indicators: histology of seminiferous tubules, intact Sertoli cells (vimentin labeling), DNA integrity, cell viability, germ cell composition (Oct4 and Boule labeling). Percentages of intact seminiferous tubules decreased after vitrification/warming and returned to the level of fresh samples after culture. While percentages of cells labeled with vimentin, with intact DNA integrity, or proportions of viable cells were affected by vitrification/warming, they all reached similar or better levels than the fresh tissue after culture. Proportions of cells labeled with Boule antibodies also improved during in vitro culture post-warming. We demonstrated for the first time that BFF testes subjected to vitrification, rapid warming, and short in vitro culture were viable and maintained the ability to resume germ cell progression. Cryopreserved testicular tissues could potentially contribute to new strategies to enhance BFF assisted reproduction as well as conservation efforts.

Influence of Microwave-Assisted Drying on Structural Integrity and Viability of Testicular Tissues from Adult and Prepubertal Domestic Cats.

Anhydrous preservation is a promising approach for storage of living biomaterials at nonfreezing temperatures. Using the domestic cat model, the objectives of this study were to characterize changes in histology, DNA integrity, and viability of testicular tissues from adult versus prepubertal individuals during microwave-assisted drying. Testes from each age group were cut into small pieces before reversible membrane permeabilization, exposure to trehalose, and microwave-assisted drying during different time periods. In Experiment 1, water content was monitored for up to 40 minutes of drying. Tissues from adult or prepubertal cats experienced similar decreases of water content during the first 10 minutes. Desiccation progressed slowly between 10 and 20 minutes and then remained stable. In Experiment 2, structural properties were explored at 5, 10, and 20 minutes of desiccation. Percentages of normal seminiferous tubules were lower after 20 minutes drying in adult (43%) than in prepubertal tissues (61%). At the same time point, the proportion of cell degeneration was higher in adult (53%) than prepubertal tissues (28%). Percentages of intact DNA in tissues remained above 85% regardless of the microwave time in both age groups. Lastly, adult and prepubertal tissues only lost 33% of viability in both age groups. Collective results demonstrated for the first time that normal morphology, incidence of degeneration, DNA integrity, and viability of testicular tissues remained at acceptable levels during microwave-assisted drying for 20 minutes. Overall, prepubertal testicular tissues appeared to be more resilient to microwave-assisted desiccations than adult tissues. Importantly, water loss in the presence of trehalose after 20 minutes of desiccation already is compatible with long-term storage of testicular tissues at temperatures above -20°C, which is one step closer to future storage at supra-zero temperatures.

Recovery and cryopreservation of epididymal sperm from domestic cat using powdered coconut water (ACP-117c) and TRIS extenders.

Cryopreservation of cats epididymal spermatozoa allows the conservation of the genetic material and the study of the cryogenic effect applied to the gametes of other felines. However, this biotechnique still presents variable results, being necessary the investigation of alternative extenders. Powdered coconut water (ACP-117c) has been efficient in the sperm freezing of several species and in the cat sperm refrigeration. Therefore, we aimed to evaluate the effect of the freezing stages and the quality of the cats' epididymal spermatozoa after thawing, using ACP-117c. Epididymides (n = 36) from 18 cats were processed using TRIS (n = 18) or ACP-117c (n = 18) for sperm recovery. The sperm were immediately evaluated. Then, this was cooled, glycerolized, frozen and thawed, and re-evaluated at each stage for sperm kinetics by Computer Assisted Semen Analysis, viability, functionality (HOST), mitochondrial activity (DAB) and morphology. There was a reduction in total motility and progressive motility after thawing in both groups, and TRIS was superior to ACP-117c. The curvilinear velocity reduced after thawing with ACP-117c. Viability decreased after glycerolization in TRIS. Although it also reduced after thawing in both groups, it was higher in TRIS. There was no change on HOST. Mitochondrial activity decreased during the cryopreservation steps for both extenders. Nevertheless, TRIS presented a higher percentage of spermatozoa from DAB class I and II after thawing. Morphology did not differ between extenders. Therefore, ACP-117c is an alternative for the recovery of cat epididymal spermatozoa; however, it is not efficient for freezing. Glycerolization and thawing are the most critical stages, regardless of the extender.

Influence of different extenders on morphological and functional parameters of frozen-thawed spermatozoa of jaguar (Panthera onca).

Due to the global decrease in jaguar population, conservation strategies are essential and the development of effective semen cryopreservation protocols would contribute to the formation of germplasm banks. Therefore, the objectives were to (1) evaluate the use of TRIS and ACP-117c extenders for jaguar semen freezing, (2) describe the ultrastructural changes in sperm after cryopreservation, and (3) evaluate the binding capacity of the thawed sperm. Eight ejaculates from five mature individuals were collected by electroejaculation, extended in TRIS or a coconut based-extender (ACP-117c), and frozen in liquid nitrogen. Samples were evaluated for sperm motility, vigor, membrane functionality, mitochondrial activity, morphology (using light microscopy, scanning electron microscopy - SEM and transmission electron microscopy - TEM), sperm kinetic parameters (by computerized analysis - CASA), and sperm binding capability using an egg yolk perivitelline membrane assay. Samples preserved in TRIS presented better post-thaw motility (46.0 ±â€¯7.7%) and membrane functionality (60.5 ±â€¯4.2%) and higher mitochondrial activity (21.5 ±â€¯3.7%) than those preserved in ACP-117c (20.9 ±â€¯5.4% motile sperm; 47.1 ±â€¯2.5% functional membrane; 11.8 ±â€¯1.7% mitochondrial activity). Regarding ultrastructural evaluations, SEM showed that both extenders were able to preserve the superficial membrane of the sperm, but TEM revealed the occurrence of nuclear electron lucent points, especially in samples extended in ACP-117c. Additionally, TRIS also provided a higher number of sperm bound to the perivitelline membrane (29.5 ±â€¯3.3%) in comparison to samples diluted in ACP-117c (18.6 ±â€¯1.5%). Overall, we suggest the use of a TRIS-based extender for cryopreservation of jaguar semen.

Morphology, morphometry, ultrastructure, and mitochondrial activity of jaguar (Panthera onca) sperm.

The jaguar is categorized as "Near Threatened". Conservation strategies, therefore, are needed which include use of reproductive biotechniques. For implementation of biotechnique use, the reproductive characteristics of the species must be understood, which is currently not the case. This study, therefore, aimed to describe the detailed morphology of jaguar sperm, and to evaluate the sperm mitochondrial activity. Five male adults were used. Slides stained with Rose Bengal were used for morphometric and morphological analyses. The length and the width of the sperm head were measured, as well as the length of the middle piece, the tail, and the total length. Scanning and transmission electron microscopy were used for ultrastructural analysis. Mitochondrial function was assessed using the marker 3,3'-diaminobenzidine (DAB). The results are expressed as means ± SEM. The most significant morphological abnormalities observed were head (9 ± 1.7%) and tail defects (12.5 ± 3.3%). The width and length of the head were 3.6 ± 0.03 µm and 4.9 ± 0.02 µm, respectively. The middle piece measured 9.7 ± 0.3 µm, the tail measured 54.5 ± 4.4 µm, and the total length of the sperm was 59.5 ± 0.1 µm. Electron-lucent regions and approximately 54 mitochondrial spirals in the middle piece were identified in the nucleus using electron microscopy. The greatest percentages of cells were classified as DAB I (46.6 ± 4.9%) and DAB II (38 ± 4.4%). The data provide detailed information on the sperm characteristics of jaguars and can support research on germplasm conservation for the species.

Influence of warming and reanimation conditions on seminiferous tubule morphology, mitochondrial activity, and cell composition of vitrified testicular tissues in the domestic cat model.

Understanding critical roles of warming and reanimation is critical to improve the survival of vitrified testicular tissue in domestic cats. The objective was to study structural and functional properties of testicular tissues from prepubertal domestic cats after standard vitrification followed by two warming protocols (directly at 37°C or with a 5-second pre-exposure to 50°C) and three reanimation time points (immediately, 24 h and 5 days post-warming). In Experiment 1, tissues were evaluated for histo-morphology and mitochondrial activity immediately or 24 h after warming protocols. In Experiment 2, cell viability, DNA fragmentation, and germ cell composition were assessed immediately, 24 h, or 5 days after optimal warming. Preservation of seminiferous tubule structure was better using warming at 50°C for five seconds, and survival of somatic as well as germinal cells was higher compared to direct warming at 37°C for one minute. Short term in vitro culture (for reanimation) also proved that cellular composition and functionality were better preserved when warmed for a short time at 50°C. Collective data showed that short warming at 50°C led to better quality of seminiferous tubule structure and cell composition after vitrification and short-term culture. In addition, data suggest clear directions to further understand and optimize testicular tissue survival after fertility preservation procedures.

Seminal plasma and sperm proteome of ring-tailed coatis (Nasua nasua, Linnaeus, 1766).

Ring-tailed coati is listed as a species of least concern in the International Union for Conservation of Nature (IUCN) Red List, however, there has been a sharp decline in their population. The present study was conducted to evaluate the major proteins of both seminal plasma and sperm in ring-tailed coatis. Semen sample was collected from three adult coatis and evaluated for their morphological characteristics. Further, the sample was centrifuged to separate spermatozoa from seminal plasma, and then stored in liquid nitrogen. The seminal plasma and sperm proteins were subjected to one-dimensional (1-D) sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and identified by mass spectrometry. Gene ontology and protein networks were analyzed using bioinformatics tools. Based on sperm concentration and average protein content of the semen, the concentration of protein/spermatozoon was found to be 104.69 ±â€¯44.43 µg. The analysis of SDS-PAGE gels showed 20.3 ±â€¯3.1 and 17 ±â€¯2 protein bands/lane for seminal plasma and sperm, respectively. In-gel protein digestion and peptide analysis by mass spectrometry revealed 238 and 246 proteins in the seminal plasma and sperm, respectively. The gene ontology analysis revealed that the proteins of seminal plasma mainly participated in cellular (35%) and regulatory (21%) processes. According to their cellular localization, seminal plasma proteins were categorized as structural (18%), extracellular (17%), and nuclear (14%) proteins with molecular functions, such as catalytic activity (43%) and binding (43%). The sperm proteins were also involved in cellular (38%) and regulatory (23%) processes, and mainly categorized as extracellular (17%), nuclear (13%), and cytoplasmic (10%) proteins. The major molecular functions of the sperm proteins were catalytic activity (44%) and binding (42%). These results indicated that the seminal plasma of ring-tailed coati has an array of proteins that can potentially modulate several sperm functions, from sperm protection to oocyte binding. However, further studies are necessary to interpret the roles of these major seminal plasma proteins in coatis.

Vitrification of testicular tissue from prepubertal cats in cryotubes using different cryoprotectant associations.

Protocols for the cryopreservation of testicular tissue are not yet established. In cats, few studies have been conducted on testicular vitrification using different cryoprotectant associations (CPAs). Thus, the objective of this study was to compare the effect of different CPAs on the vitrification of testicular tissue from prepubertal cats in cryotubes. We used 10 pairs of testicles, with each pair divided into 8 fragments that were distributed into different experimental groups. Two of these fragments were allocated into the control group (CG) and the other six were distributed according to the CPAs to be tested (dimethyl sulfoxide (DMSO)/glycerol (GLY), ethylene glycol (EG)/GLY, or DMSO/EG). The cryoprotectants were used at a final concentration of 5.6 M. The fragments were subjected to vitrification in cryotubes and after 1 week, they were warmed and processed for histomorphologic assessment, quantification of nucleolar organizer regions (NORs), and determination of cell viability. The DMSO/EG and EG/GLY groups presented the greatest cell separation from the cell basement membrane and the highest degrees of retraction of the basal membrane. In these aspects, DMSO/GLY did not differ from the CG and both were significantly superior to the other groups. In terms of cell distinction, visibility of the nucleus, and nuclear condensation, all the vitrified groups had significantly lower values than the CG, while the DMSO/GLY and EG/GLY groups did not differ between themselves. Through the quantification of NORs, the potential for cell proliferation of the CG was found to have a mean of 3.80, while DMSO/GLY presented a mean of 3.60, and thus there was no significant difference between these two groups. The proliferation potentials of both groups were significantly superior to that of the DMSO/EG (mean: 2.07) and EG/GLY (mean: 1.98) groups. In the CG and DMSO/GLY group, 91.8% and 64.2% of cells, respectively, were found to be viable. The cell viabilities of both groups were significantly superior to those of DMSO/EG (52.5%) and EG/GLY (57.10%). Vitrification in cryotubes combined with the use of the DMSO/GLY association was effective in maintaining the histomorphology, cell proliferation potential, and cell viability of testicular tissue from prepubertal cats after cryopreservation.

Cryopreservation of testicular tissue: an alternative to maintain the reproductive capacity in different animal species / Criopreservação do tecido testicular: uma alternativa para manter a capacidade reprodutiva em diferentes espécies animais

ABSTRACT: Cryopreservation of testicular tissue enables the maintenance of reproductive capacity in different animal species, and contributes to the formation of gene banks for endangered species. The spermatogonia present in the testes can be grown in vitro and the sperm obtained can be used in artificial breeding programs. This review aimed to describe the main techniques of testicular cryopreservation, the main cryoprotectants used, as well as the progress made in different animal species thus far. In the last decade, significant progress has been made in obtaining viable and functional germ cells from testicular tissue. However, more research is needed to better establish protocols that can be used in clinical practice with various species.

RESUMO: A criopreservação do tecido testicular possibilita a manutenção da capacidade reprodutiva em diferentes espécies animais e contribui para a formação de bancos de germoplasma nas espécies ameaçadas de extinção. As espermatogônias presentes nos testículos podem ser cultivadas in vitro e os espermatozoides obtidos utilizados em programas de reprodução artificial. Assim, esta revisão teve como objetivo descrever as principais técnicas de criopreservação testicular, os principais crioprotetores utilizados e os avanços obtidos até o presente momento nas diferentes espécies animais. Na última década, os avanços obtidos com a utilização do tecido testicular para obtenção de células germinativas viáveis e funcionais foram significativos. Todavia, o estabelecimento de protocolos que possam ser utilizados na rotina clínica em diferentes espécies ainda necessitam de maiores esclarecimentos.

Two-dimensional sonographic and Doppler changes in the uteri of bitches according to breed, estrus cycle phase, parity, and fertility.

This study aimed to evaluate the two-dimensional and Doppler ultrasonographic features of bitches' uteri according to breed, cycle phase, parity and fertility during the follicular and early diestrus phases. Thirty-nine pubertal bitches were divided into groups according to breed, parity, and fertility. Sonographic assessments started from the first day of vaginal bleeding and were performed weekly for a month. The diameter of the uterine body was measured longitudinally and the uterine characteristics observed sonographically were evaluated. The resistivity index (RI) and pulsatility index (PI) of the uterine artery were calculated and the spectral morphology analyzed subjectively. The uterine diameter increased from proestrus to the diestrus regardless of the breed or parity. Multiparous bitches of both breeds had higher uterine diameters than nulliparous bitches, except Fila Brasileiro bitches in estrus. In diestrus and proestrus, the uterine diameters were significantly the largest for multiparous bitches, followed by the primiparous bitches and smallest for nulliparous bitches. The uterine diameter was larger in Fila Brasileiro females than in French Bulldogs during estrus and diestrus. The RI did not differ during the different phases of the cycle for the same breed. However, the RI was higher in nulliparous and primiparous Fila Brasileiro females compared to French Bulldog females. Within Fila Brasileiro, multiparous bitches showed lower RI than nulliparous and primiparous bitches. Higher PI values were found during proestrus. All multiparous French Bulldog bitches had greater PI than nulliparous bitches, while multiparous Fila bitches had lower PI. Nulliparous and primiparous Fila bitches had larger PI larger than bitches with the same reproductive status of the breed French Bulldog. Infertile bitches had higher RI and PI than bitches considered fertile during the initial estrus and diestrus. Triphasic and types A, C, and D spectral morphologies were found in females who did not gestate; while pregnant females showed spectral morphologies of type B, C and D. Hence, it was concluded that the breed, the phase of estrus cycle and pregnancy history should be considered when studies the uterine artery flow during estrus and early diestrus using investigations such as Doppler assessment, which can be an important tool in diagnosing fertility in dogs.

Proteomic characterization of canine seminal plasma.

The present study was conducted to identify the major proteome of the sperm-rich fraction and prostatic fraction of canine seminal plasma. Three semen samples from four healthy dogs were obtained by digital manipulation. The pre-sperm fraction, sperm-rich fraction and prostatic fraction were separated from each ejaculate. Immediately after sperm analysis, a protease inhibitor was added to the sperm-rich fraction and prostatic fraction, and the fractions were separately centrifuged and frozen at -80 °C. The samples were thawed, re-centrifuged, and the total protein concentration was determined. Samples were subjected to 1D SDS-PAGE and Coomassie-blue stained gels, were analyzed by Quantity One 1D Analysis Software. Bands detected in the gels were excised and proteins subjected to digestion with trypsin. Proteins were identified by nano-HPLC-MS and tools of bioinformatics. Tandem mass spectrometry allowed the detection of 268 proteins in the gels of sperm-rich fraction and prostatic fraction of canine ejaculate. A total of 251 proteins were common to the sperm-rich and prostatic fractions, while 17 proteins were present in the sperm-rich fraction and absent in the prostatic fraction. The intensity of the bands detected in range 1 and 2 represented 46.5% of all of the band intensities detected in the 1D gels for proteins of the sperm-rich fraction and 53.0% of all bands in the prostatic fraction. Arginine esterase and lactotransferrin precursor were the protein with the highest intensity observed in the both fractions. Among the proteins present only in the sperm-rich fraction, the proteins UPF0764 protein C16orf89 homolog and epididymal-specific lipocalin-9 were the most abundant. In conclusion, canine sperm-rich fraction and prostatic fraction express a very diverse set of proteins, with unique biochemical properties and functions. Moreover, although most proteins are common to both sperm-rich fraction and prostatic fraction, there are some exclusive proteins in sperm-rich fraction.

Can maternal-fetal hemodynamics influence prenatal development in dogs?

The goals of this study were to report embryonic and fetal ultrasound changes and compare blood flow of uteroplacental and umbilical arteries of normal and abnormal conceptus. Accordingly, from the day of mating or artificial insemination, all fetuses in 60 pregnancies were evaluated weekly. According to the ultrasound findings, the gestational age was determined and the conceptuses were divided into normal or abnormal (embryonic and fetal abnormalities). The two-dimensional ultrasound assessment consists of measuring and evaluating the echogenicity of conceptus and extra-fetal structures. Doppler velocimetry measured the resistivity index (RI) and pulsatility index (PI) of uteroplacental and umbilical arteries. Two-dimensional and Doppler measurements were expressed as mean and standard deviation. Differences between normal and abnormal groups were subject to Mann-Whitney test (P<0.05). Of 264 fetuses, 15.90% showed embryonic abnormalities (resorption) and 5.68% presented fetal abnormalities (congenital abnormalities, fetal underdevelopment and fetal death). We observed a reduced diameter and abnormalities in the contour of gestational vesicle, lack of viability, increased placental thickness, increased fluid echogenicity and increases in RI and PI of uteroplacental arteries of conceptuses with embryonic resorption between the 2nd and 4th weeks. Fetuses with abnormalities showed changes in the flow of uteroplacental and umbilical arteries prior to visualization of two-dimensional alterations and different vascular behavior according to the classification of the change. Results show that ultrasound is efficient for the detection of embryonic and fetal abnormalities. When combined with Doppler ultrasound, it allows early detection of gestational changes, as well as hemodynamic changes, in conceptuses with abnormalities, which may influence their development.

Proteins of the canine seminal plasma / Proteínas do plasma seminal canino

ABSTRACT: Studies have been performed to identify the proteins present in canine seminal plasma (SP) and relate them to sperm quality as well as to discover molecular markers of reproductive tract diseases. There is evidence that heparin-binding proteins, zinc-binding proteins, and lactoferrin as well as the matrix metalloproteinase, superoxide dismutase, catalase, and glutathione peroxidase enzymes are associated with canine sperm quality. Other studies indicate that prolactin and enzymes like arginine esterase, acid phosphatase, and alkaline phosphatase could be successfully used as biomarkers of reproductive disorders. Thus, the present literature review aims to address aspects related to proteins of the canine SP, their influence on fertility, and their importance as biomarkers of reproductive disorders.

RESUMO: Pesquisas têm sido realizadas para identificar as proteínas presentes no plasma seminal canino, com o intuito de relacioná-las com a qualidade espermática, bem como buscar por marcadores moleculares de patologias do trato reprodutivo. Há evidências de que as proteínas ligadoras de heparina, ligadoras de zinco, a lactoferrina, bem como as enzimas matrix metalloproteinase, superoxide dismutase, catalase e a glutationa peroxidase estão relacionadas com a qualidade seminal canina. Outras pesquisas indicam que a prolactina, e as enzimas arginina esterase, fosfatase ácida e fosfatase alcalina poderiam ser utilizadas com sucesso como biomarcadores de doenças reprodutivas. Assim, esta revisão de literatura objetiva abordar aspectos relacionados às proteínas do plasma seminal canino, suas influências sobre a fertilidade, e sua importância como biomarcadores de doenças reprodutivas.