CRYOPRESERVATION OF CANINE SPERMATOZOA IN A SIMPLE EXTENDER COMPOSED OF SKIM MILK, GLUCOSE AND GLYCEROL
Notice bibliographique
Résumé
Cryopreservation of canine spermatozoa offers the potential to exchange genetic materials between and among countries, and improve breeding management programs of working dogs, including guide dogs for the blind. The conventional diluents for canine semen have successfully used egg yolk (EY) to preserve canine spermatozoa against cold shock during the freezing and thawing process. However, due to outbreak of avian influenza in the world, transportation of frozen semen with EY has become difficult. Thus, it is an urgent subject to develop a novel cryoprotectant without EY for canine spermatozoa. The objective of the present study was to evaluate the efficacy of skim milk and sugar (SS) based extender without EY for cryopreservation of canine spermatozoa. A total of 6 ejaculates from 4 Labrador retrievers were collected by digital manipulation into sterile plastic tubes. Only the sperm-rich fractions of the ejaculates were collected. Collected ejaculates were extended in the first extenders at a sperm concentration of 200×106 sperms/ml. SS based extender (30 mg/ml skim milk and 0.3 M glucose) or EY based extender (20% [v/v] EY, 24 mg/ml Tris, 14 mg/ml citric acid monohydrate, 0.8 mg/ml glucose, 0.65 mg/ml penicillin G potassium and 1 mg/ml streptomycin sulphate) were used for the first extenders. After 3h equilibration at 4 °C, the equivalent volume of the second extenders which has same composition as that of first extender except that it contained 14% (v/v) glycerol, was added to the semen aliquots, and the semen samples were left at 4 °C for 15 min. Final sperm concentration after the addition of the second extender to the semen samples were 100 × 106 sperms/ml. The extended semen was packed in a 0.25 ml straw, and then was frozen in a closed styrofoam box (24.5 × 17.5 × 17.5 cm) on a rack 6 cm above the surface of LN2 for 15 min. The straws were plunged into LN2 and stored until evaluation. After thawing by immersing the straws in a water bath at 37 °C for 60 s, the content of each straw was emptied into a 1.5 ml eppendorf tube, and the each sample was evaluated using a light microscope supplied with a Computer Assisted Sperm Analysis (CASA) system. The proportion of total motile spermatozoa (%; TMS) and some motility parameters (straight-line velocity, amplitude of lateral head displacement, etc.) were determined. TMS of each samples were 25–85% (average: 50.2 ± 8.8) in the SS group and 13–83% (average: 48.0 ± 11.0) in the EY group. The percentages of TMS in the SS group to the EY group were 67.3–215.0 in each sample, and there was no significant difference between two groups. Moreover, other motility parameters in the SS group were similar to the corresponding parameters in the EY group. These results suggest that the simple extender composed of skim milk, glucose and glycerol is available for cryopreservation of canine spermatozoa, and it may contribute to efficient production of guide dogs for the blind. (poster)
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Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».