The Effects of Hoechst 33342 Staining and the Male Sample Donor on the Sorting Efficiency of Canine Spermatozoa

Canine Semen Evaluation and Processing

Advances in canine semen evaluation have progressed over time in fits and spurts, interspersed with long periods of relative inactivity. Despite exciting advances in the semen analysis, clinical canine theriogenology has been in a period of relative inactivity for a number of decades since initial advances in canine semen freezing in the mid 20th century. This review describes ways that the clinical practice of canine semen evaluation should improve, given the state of current knowledge.

Birth of puppies of predetermined sex after artificial insemination with a low number of sex-sorted, frozen-thawed spermatozoa in field conditions

The aim of this study was to evaluate fertility and sex ratios after artificial insemination in dogs under field conditions. Semen was cryopreserved as unsorted (control) or was separated into X- and Y-chromosome-bearing sperm using a cell sorter. Sixty female dogs were inseminated with frozen-thawed spermatozoa of 100 × 10⁶ unsorted (a dose in practice) and 4 × 10⁶ sorted (X and Y group, respectively). A total of 20 dogs became pregnant and 126 puppies were born from the three groups. The percentage of parturition was similar for the X (5/20; 25.0%) and Y (4/20; 20.0%) group (P > 0.05), but lower than controls (11/20; 55.0%) (P < 0.05). Ultimately 28 out of the 32 puppies produced from X group were female (87.5%) and 19/22 (86.4%) puppies of Y group were male. In contrast, sex ratio (51.4% to 48.6%) in the control was significantly different from the X, Y group (P < 0.05). However, male and female puppies in the control had similar birth weights and weaning weights to those from the X and Y groups. This preliminary information indicated that normal puppies of predicted sex can be produced with low numbers of sorted cryopreserved dog spermatozoa at a farm level, making sperm-sexing technology potentially applicable for elite breeding units.

Increased expression of SUMO1P3 predicts poor prognosis and promotes tumor growth and metastasis in bladder cancer

Bladder cancer is one of the most common malignancies worldwide. Long non-coding RNAs (lncRNAs) are a class of non-coding RNAs that play crucial roles in diverse biological processes. The pseudogene-expressed lncRNA is one major type of lncRNA family. Small ubiquitin-like modifier (SUMO) 1 pseudogene 3, (SUMO1P3) is a novel indentified lncRNA that was previously reported to be up-regulated in gastric cancer. However, we know nothing about the biological function and underlying mechanism of SUMO1P3 in tumor. Furthermore, the relationship between SUMO1P3 and bladder cancer is completely unknown. We hypothesized that SUMO1P3 also have roles in bladder cancer.In this study, we found that SUMO1P3 was significantly up-regulated in bladder cancer tissues compared with paired-adjacent nontumorous tissues in a cohort of 55 bladder cancer patients. Moreover, up-regulated SUMO1P3 expression was positively correlated with greater histological grade (P<0.05) and advanced TNM stage (P<0.05). Furthermore, we found cell proliferation / migration inhibition and apoptosis induction were also observed in SUMO1P3 siRNA-transfected bladder cancer cells. Our data suggest that SUMO1P3 plays oncogenic roles in bladder cancer and can be used as a potential prognostic and therapeutic target.

Storage of sexed boar spermatozoa: Limits and perspectives

Despite the great potential application of sex-sorted spermatozoa in swine, the technology is not practiced in the pig industry because of technical factors and species-specific issues. The susceptibility of boar spermatozoa to stresses induced by the sorting procedure, the relative slowness of the sex-sorting process together with the high sperm numbers required for routine artificial insemination in pig are some of the main factors limiting the commercial application of this technology in pigs. This review briefly describes the damage to spermatozoa during sex sorting, focusing on an additional limiting factor: increased susceptibility of sexed boar spermatozoa to injuries induced by liquid storage and cryopreservation that, in turn, impairs sperm quality leading to unsatisfactory results in vivo. Strategies to extend the lifespan of sex-sorted boar spermatozoa and to improve their fertilizing ability after liquid storage or cryopreservation need to be implemented before this technology can be used in pig farms. In this regard, encapsulation in barium alginate membranes could be a promising technique to optimize the in vivo use of sexed boar spermatozoa, by protecting, targeting, and controlling the release of sperm into the female genital tract.

Sex-sorted canine sperm cryopreservation: limits and procedural considerations

The aim of this study was to define a protocol to store dog sperm before and after sorting to obtain an insemination dose sufficient to allow the conception by artificial insemination. Experiment 1 and 2 were performed to evaluate the more appropriate extender for preserving at room temperature dog sperm before and after sorting. Four extenders were tested: (1) Tris-fructose-citrate (TFC), (2) Tris-glucose-citrate (TGC), (3) modified Tyrode's albumin lactate pyruvate medium (mTALP), and (4) third fraction of the ejaculate (after centrifugation at 5000× g for 10 minutes; III FRAC). Experiment 3 and 4 were performed to evaluate the ability of dog semen to withstand sex sorting and freezing/thawing. Modified Tyrode's albumin lactate pyruvate medium was the best extender for canine sperm storage at room temperature (20 °C-25 °C) before (total motility: TFC, 8.3 ± 1.7; TGC, 50.0 ± 11.5; mTALP, 70.0 ± 0.1; III FRAC, 25.0 ± 1 0.4; P < 0.05) and after sorting (total motility: TFC, 7.3 ± 1.5; TGC, 10.3 ± 1.5; mTALP, 33.3 ± 6.7; III FRAC, 8.7 ± 5.8; P < 0.05), even if at 24-hour sorted sperm quality was impaired in all extenders tested herein. Sperm quality decreased after sorting (total motility: control, 92.5 ± 0.9; sorted, 52.9 ± 6.0; P < 0.05) and, especially, after freezing/thawing (total motility: frozen control, 25.7 ± 4.1; frozen sorted, 2.4 ± 1.2; P < 0.05). In conclusion, mTALP is an appropriate medium for canine sperm storage before and soon after sorting (hours), but a long storage period of sexed sperm at room temperature is not adequate. Cryopreservation greatly impaired sperm quality, and further studies are needed to optimize the freezing protocol for sexed dog sperm.

Effects of rapid cooling prior to freezing on the quality of canine cryopreserved spermatozoa

The aim of this study was to evaluate the effects of rapid cooling prior to freezing on frozen-thawed canine sperm quality. In experiment 1, centrifuged ejaculates from 6 dogs were pooled, split into 4 aliquots and cryopreserved by the Uppsala procedure using different cooling rates (control, cooling speed 18 C/90 min and average cooling rate 0.2 C/min; rapid, cooling speed 18 C/8 min and average cooling rate 2.25 C/min) in combination with 2 glycerol addition protocols (fractionated or unfractionated). In experiment 2, centrifuged ejaculates from 4 dogs were processed individually using the same cooling rates described in experiment 1 in combination with an unfractionated glycerol addition protocol. Each of the experiments was replicated 5 times. Sperm quality was evaluated after 30 and 150 min of post-thawing incubation at 38 C. Total motility (TM), progressive motility (PM) and quality of movement parameters were assessed using a computerized system, and sperm viability (spermatozoa with intact plasma and acrosome membranes) was assessed using flow cytometry (H-42/PI/FITC-PNA). Values for TM, PM, viable spermatozoa and the quality of movement parameters after thawing were not significantly affected by the cooling rate. The interaction between the cooling rate and the added glycerol protocol was not significant. There were significant differences among the males (P<0.01) in the sperm quality parameters evaluated after thawing. The interaction between the males and the cooling rate was not significant. In conclusion, canine spermatozoa can be cryopreserved using the Uppsala method at an average cooling rate of 2.25 C/min prior to freezing together with addition of fractionated or unfractionated glycerol.

Quality of chilled and cold-stored (5 °C) canine spermatozoa submitted to different rapid cooling rates

The aim of this study was to evaluate the sperm quality in chilled canine semen using different cooling rates from room temperature (23 °C) to 5 °C and subsequently cold-stored at 5 °C for up to 96 hours. In experiment 1, semen samples from five dogs were pooled, diluted in Tris-fructose-citrate extender with 20% egg yolk and split into four aliquots that were chilled to 5 °C using different cooling rates of 2.25, 0.9, 0.45, and 0.2 (control) °C/min. In experiment 2, semen from five dogs was processed individually as described above and split into two aliquots that were chilled to 5 °C using rates of either 2.25 °C/min or 0.2 °C/min. In both experiments, the sperm quality (i.e., sperm motility and viability) was evaluated before cooling and after 0, 24, 48, 72, and 96 hours of storage at 5 °C. The total motility, progressive motility, and quality of movement parameters were assessed using computer-assisted analysis system, and the percentage of viable spermatozoa was determined using flow cytometry (H-42/PI//FITC-PNA). The cooling rate did not influence the sperm quality parameters at any of the evaluation times. All evaluated males showed the same response to chilling semen at a rapid cooling rate. Storage time negatively influenced (P < 0.05) sperm motility, regardless of the cooling rate used. In conclusion, canine sperm could be chilled and stored for 96 hours at 5 °C in a Tris-fructose extender with 20% egg yolk using rapid cooling rates, with values for sperm quality similar to those from a conventional protocol.