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.

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.

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.

Revisiting spontaneous Raman scattering for direct oxygen atom quantification.

In this Letter, the counterintuitive and largely unknown Raman activity of oxygen atoms is evaluated for its capacity to determine absolute densities in gases with significant O-density. The study involves ${\rm CO}_2$ microwave plasma to generate a self-calibrating mixture and establish accurate cross sections for the $^3{\!P_2}{\leftrightarrow ^3}{\!P_1}$ and $^3{\!P_2}{\leftrightarrow ^3}{\!P_0}$ transitions. The approach requires conservation of stoichiometry, confirmed within experimental uncertainty by a 1D fluid model. The measurements yield ${\sigma _{J = 2 \to 1}} = 5.27 \pm _{{\rm sys}:0.53}^{{\rm rand}:0.17} \times {10^{- 31}}\;{{\rm cm}^2}/{\rm sr}$ and ${\sigma _{J = 2 \to 0}} = 2.11 \pm _{{\rm sys}:0.21}^{{\rm rand}:0.06} \times {10^{- 31}}\;{{\rm cm}^2}/{\rm sr}$, and the detection limit is estimated to be $1 \times {10^{15}}\;{{\rm cm}^{- 3}}$ for systems without other scattering species.

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.