Mesenchymal stem cells of Oravka chicken breed: promising path to biodiversity conservation

Mesenchymal stem cells (MSCs) are multilineage cells able to differentiate into other cell types. MSCs derived from bone marrow or compact bones are the most accessible stem cells used in tissue engineering. Therefore, the aim of this study was to isolate, characterize and cryopreserve MSCs of endangered Oravka chicken breed. MSCs were obtained from compact bones of the femur and tibiotarsus. MSCs were spindle-shaped and were able to differentiate into osteo-, adipo-, and chondrocytes under the specific differentiation conditions. Furthermore, MSCs were positive for surface markers such as CD29, CD44, CD73, CD90, CD105, CD146 and negative for CD34CD45 by flow cytometry. Moreover, MSCs demonstrated high positivity of "stemness" markers aldehyde dehydrogenase, alkaline phosphatase as well as for intracellular markers vimentin, desmin, α-SMA. Subsequently, MSCs were cryopreserved using 10% dimethyl sulfoxide in liquid nitrogen. Based on the results from the viability, phenotype, and ultrastructure assessment we can concluded that the MSCs were not negatively affected by the cryopreservation. Finally, MSCs of endangered Oravka chicken breed were successfully stored in animal gene bank, thus making them a valuable genetic resource.

VITALITY AND BACTERIOLOGICAL PROFILE OF LIPTOV BOLD-SPOTTED RABBIT SEMEN

Since semen quality is important for the successful artificial insemination (AI) or cryopreservation, we focused on the evaluation of Slovak national rabbit breeds, New Zealand rabbit and Liptov Bold-Spotted rabbit semen as a possible source of gene reserve. Besides standard sperm traits such as motility, viability, acrosome integrity, and oxidative damage (ROS), bacterial profiles were also assessed in semen samples of New Zealand rabbit (control; n=2; N1 and N2) and Liptov Bold-Spotted rabbit (experimental; n=2; L2 and L4). After initial analysis, samples were divided into good (>70%) and poor (<70%) quality samples according to motility and viability. The results showed significantly higher (P<0.05) totally motile spermatozoa in N1, N2 (76.53±1.22%; 77.30±1.22%) compared to L2 (35.86±5.39%) as well as higher progressively motile spermatozoa in N1 (60.53±1.35%) and N2 (68.13±4.14%) compared to L2 (24.16±1.95%). However, no significant differences in L4 (45.11±4.05%) compared to other groups were recorded. The proportion of dead/live, apoptotic, acrosome damaged, mitochondrial active and ROS produced rabbit sperm was assessed via flow cytometry using fluorescent dyes: DRAQ7, SYBR-14, Yo-Pro-1, PNA, MitoTracker and CellROX, respectively. Significant (p<0.05) decrease of live sperm was observed in L4 (42.73±6.89%) compared to N1 (75.22±5.75%) sample. In adittion, significant (p<0.05) increased presence of dead sperm was in L4 (41.20±10.16%) group compared to N2 (11.16±3.01%). The activity of rabbit sperm mitochondria assessed via mitochondrial membrane potential was significantly (p<0.05) higher in N1 (93.37±1.46%) and N2 (94.35±0.74%) compared to L4 (57.34±1.92). The results from the bacteriological analysis showed that the sperm in good quality (N1 and N2) contained mainly microbial genus such as Brevundimonas, Brevibacterium, Bacillus or Achromobacter. Other samples with poor quality (L2, L4) contained different kind of bacterial genus such as Pseudomonas, Delftia, Acidovorax, Acinetobacter or Staphylococcus. Although the microorganism profile appeared different, obligate pathogenic species were not present. Therefore, further analyses are needed to find out the reason of poor semen quality.

Comprehensive Flow-Cytometric Quality Assessment of Ram Sperm Intended for Gene Banking Using Standard and Novel Fertility Biomarkers

Flow cytometry becomes a common method for analysis of spermatozoa quality. Standard sperm characteristics such as viability, acrosome and chromatin integrity, oxidative damage (ROS) etc. can be easily assess in any animal semen samples. Moreover, several fertility-related markers were observed in humans and some other mammals. However, these fertility biomarkers have not been previously studied in ram. The aim of this study was to optimize the flow-cytometric analysis of these standard and novel markers in ram semen. Ram semen samples from Slovak native sheep breeds were analyzed using CASA system for motility and concentration and were subsequently stained with several fluorescent dyes or specific antibodies to evaluate sperm viability (SYBR-14), apoptosis (Annexin V, YO-PRO-1, FLICA, Caspases 3/7), acrosome status (PNA, LCA, GAPDHS), capacitation (merocyanine 540, FLUO-4 AM), mitochondrial activity (MitoTracker Green, rhodamine 123, JC-1), ROS (CM-H2DCFDA, DHE, MitoSOX Red, BODIPY), chromatin (acridine orange), leukocyte content, ubiquitination and aggresome formation, and overexpression of negative biomarkers (MKRN1, SPTRX-3, PAWP, H3K4me2). Analyzed semen samples were divided into two groups according to viability as indicators of semen quality: Group 1 (viability over 60%) and Group 2 (viability under 60%). Significant (p < 0.05) differences were found between these groups in sperm motility and concentration, apoptosis, acrosome integrity (only PNA), mitochondrial activity, ROS production (except for DHE), leukocyte and aggresome content, and high PAWP expression. In conclusion, several standard and novel fluorescent probes have been confirmed to be suitable for multiplex ram semen analysis by flow cytometry as well as several antibodies have been validated for the specific detection of ubiquitin, PAWP and H3K4me2 in ram spermatozoa.

The Cryopreserved Sperm Traits of Various Ram Breeds: Towards Biodiversity Conservation

The aim of our research was to compare three Slovak sheep breeds in the quality parameters of cryopreserved sperm. The ejaculates of Slovak Dairy (SD), Native Wallachian (NW), and Improved Wallachian (IW) sheep rams (n = 12) were collected by electro-ejaculation. Heterospermic samples were created from suitable ejaculates, separately for each breed (at least 90% of total and 80% of progressive motility). Samples were equilibrated in a Triladyl® diluent and frozen by automated freezing. Sperm samples were subjected to the motility, morphology, (CASA), viability and apoptosis (DRAQ7/Yo-Pro-1), fertilizing capability (penetration/fertilization test (P/F) in vitro) and acrosomal status (transmission electron microscopy) assays before freezing and after thawing. It was found that there were no significant differences (p < 0.05) between the evaluated breeds in motility, viability, apoptosis, morphological properties, and fertilizing ability of cryopreserved sperm. Significant differences occurred in acrosomal status. Our results demonstrate that the use of the selected cryopreservation protocol is suitable for at least three different sheep breeds, which can greatly benefit the biodiversity protection and simplifies the creation of an animal genetic resources gene bank.

Effect of selected natural and synthetic substances on rabbit reproduction-A mini review

Numerous natural and synthetic substances have effects on reproduction through several mechanisms. This review aims to summarize the impact of green tea (GT), yucca schidigera (YS) extract, curcuma longa (CL), adenosine 3',5'-cyclic monophosphate (cAMP) and isobutyl-1-methyl-xanthine (IBMX) stimulators on rabbit reproduction performance. To obtain a comprehensive overview of this topic, the keywords "reproduction," "substances," "spermatogenesis," "embryogenesis,"hormonal profil", "green tea", "yucca schidigera" were searched in such databases as WOS and PubMed to obtain relevant information. Spermatozoa profile was positively effected by the GT and YS, however, cAMP inhibitors stimulated spermatozoa motility resulted in positive or negative effects depending on the doses. Similarly, embryogenesis and hormonal profile were positively influenced by the GT, YS, cAMP and IBMX in a proper administration dose. Further research is needed to improve current knowledge about these substances to identify potential effects on the other reproduction parameters. Furthermore, future studies should combine GT, YS and CL with different plant extracts to determine their effects on spermatozoa status, embryogenesis as well as hormonal profile as key outcomes. This review summarizes current knowledge about effect of natural and synthetic substances on rabbit reproduction.

Molecular Profiling and Gene Banking of Rabbit EPCs Derived from Two Biological Sources

Endothelial progenitor cells (EPCs) have been broadly studied for several years due to their outstanding regenerative potential. Moreover, these cells might be a valuable source of genetic information for the preservation of endangered animal species. However, a controversy regarding their characterization still exists. The aim of this study was to isolate and compare the rabbit peripheral blood- and bone marrow-derived EPCs with human umbilical vein endothelial cells (HUVECs) in terms of their phenotype and morphology that could be affected by the passage number or cryopreservation as well as to assess their possible neuro-differentiation potential. Briefly, cells were isolated and cultured under standard endothelial conditions until passage 3. The morphological changes during the culture were monitored and each passage was analyzed for the typical phenotype using flow cytometry, quantitative real–time polymerase chain reaction (qPCR) and novel digital droplet PCR (ddPCR), and compared to HUVECs. The neurogenic differentiation was induced using a commercial kit. Rabbit cells were also cryopreserved for at least 3 months and then analyzed after thawing. According to the obtained results, both rabbit EPCs exhibit a spindle-shaped morphology and high proliferation rate. The both cell lines possess same stable phenotype: CD14⁻CD29⁺CD31⁻CD34⁻CD44⁺CD45⁻CD49f⁺CD73⁺CD90⁺CD105⁺CD133⁻CD146⁻CD166⁺VE-cadherin⁺VEGFR-2⁺SSEA-4⁺MSCA-1⁻vWF⁺eNOS⁺AcLDL⁺ALDH⁺vimentin⁺desmin⁺α-SMA⁺, slightly different from HUVECs. Moreover, both induced rabbit EPCs exhibit neuron-like morphological changes and expression of neuronal markers ENO2 and MAP2. In addition, cryopreserved rabbit cells maintained high viability (>85%) and endothelial phenotype after thawing. In conclusion, our findings suggest that cells expanded from the rabbit peripheral blood and bone marrow are of the endothelial origin with a stable marker expression and interesting proliferation and differentiation capacity.

Microscopic Assessment of Dead Cell Ratio in Cryopreserved Chicken Primordial Germ Cells

This study aimed to compare three methods of cell death assessment [trypan blue exclusion (TBE), propidium iodide viability assay (PIVA), and transmission electron microscopy] to evaluate fresh and frozen-thawed chicken primordial germ cells (PGCs). For this study, chicken PGCs were collected from ROSS 908 and Oravka breed hens, cryopreserved-thawed according to the protocol, and submitted for different cell death assessments. We observed significant differences between TBE and PIVA techniques in the detectable proportion of dead cells in fresh (14.14 ± 1.27 versus 7.16 ± 1.02%, respectively) and frozen-thawed (44.00 ± 2.11 versus 33.33 ± 1.67%, respectively) samples of the Oravka breed. Moreover, significant differences (p < 0.05) between TBE and PIVA techniques in the detectable proportion of dead cells in fresh (9.20 ± 0.60 versus 5.37 ± 0.51%) samples of ROSS 908 breed were recorded. Differences may be due to methodological, sensitivity, and toxicity features of each technique tested, where TB stains cell cytoplasm of dead cells and PI penetrates and intercalates into DNA of dead cells. Therefore, we suggest using a more precise and sensitive PIVA for viability evaluation of PGCs. Further research is needed to apply various fluorochromes for more detailed cell viability evaluation.

The Assessment of Cryopreservation on the Quality of Endangered Oravka Rooster Spermatozoa Using Casa and Cytometry

BACKGROUND

Preservation of genetic resources in gene bank is necessary for conservation of endangered poultry species.

OBJECTIVE

This study is to characterize Oravka rooster semen quality.

MATERIALS AND METHODS

Heterospermic pool was diluted (1:1 by volume) in a freeze medium composed of a commercial diluent (Kobidil⁺, K), 8% dimethyl sulphoxide (DMSO) or 8% ethylene glycol (EG) or 8% glycerol (GL), and then frozen in liquid nitrogen vapour.

RESULTS

Spermatozoa in the GL/K⁺ had significantly higher number of motile and progressively moving spermatozoa (p < 0.05) than in DMSO/K⁺ and EG/K⁺ groups. The percentage of apoptotic and necrotic spermatozoa were significantly higher in the DMSO/K⁺ and EG/K⁺ groups compared with the GL/K⁺ group. Based on the total motility, progressive movement parameters and viability, our study showed that 8% GL diluted in Kobidil⁺ provided the highest cryoprotective effect on the Oravka rooster spermatozoa.