DETERMINATION OF MELATONIN CONCENTRATION IN SPERM CRYOPRESERVATION BY SLOW FREEZING METHOD

A beluga (Delphinapterus leucas) sperm preservation method was developed for use in genome banking and AI. In Study 1, glycerol-based cryodiluents (modified BF5F and modified Platz Diluent Variant (PDV)) were unable to maintain adequate progressive motility using straws (fast and slow freezing rate (FR)) or pellets (slow FR). Neither freezing method nor FR affected in vitro sperm characteristics (P > 0.05), but retention of prefreeze progressive motility following thawing was greater (P < 0.05) for BF5F (21%) than PDV (15%). In Study 2, examining the effects of straw freeze–thawing using BF5F with glycerol (1 and 3%, v/v) or trehalose (46 and 91 mM) on sperm characteristics, samples cryopreserved in trehalose exhibited superior (P < 0.05) in vitro parameters compared with their glycerol-treated counterparts. In Study 3, compared with a straw method, directional freezing using 91 mM trehalose enhanced (P < 0.05) sperm characteristics, with samples retaining 38%, 75% and 61% of their prefreeze progressive motility, curvilinear velocity and viability, respectively. A higher (P < 0.05) proportion of motile spermatozoa displayed rapid velocity after directional (21 ± 1%) compared with straw (12 ± 3%) freezing. Systematic development of a cryodiluent and the use of directional freezing resulted in beluga spermatozoa exhibiting adequate post-thaw quality for genome banking and use in AI.

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Initial Characterization of Male Southern Stingray (Hypanus americanus) Reproductive Parameters and Preliminary Investigation of Sperm Cryopreservation

Animals ◽

10.3390/ani11092716 ◽

2021 ◽

Vol 11 (9) ◽

pp. 2716

Author(s):

James D. Gillis ◽

Linda M. Penfold ◽

Natalie D. Mylniczenko

Keyword(s):

Sperm Count ◽

Preliminary Investigation ◽

Membrane Integrity ◽

Ringer Solution ◽

Ex Situ ◽

Total Testosterone ◽

Sperm Cryopreservation ◽

Slow Cooling ◽

Freezing Method ◽

Elasmobranch Species

This study investigated the reproductive biology and sperm cryopreservation of ex situ southern stingrays (Hypanus americanus) by semen collection and characterization and the development and validation of an enzyme-linked immunoassay for plasma total testosterone. Semen was collected in March and June using a manual massage technique, and the ejaculates were assessed for volume, pH, osmolarity, motility, status (0–5 scale: 0 = no forward progression, 5 = rapid linear progression) and total sperm count. Semen was extended in Hank’s elasmobranch ringer solution containing 10% DMSO, 10% glycerol or 5% glycerol with 5% N-methylformamide and cryopreserved using a conventional freezing method (~−50 °C/min) or a modified slow freezing method (~−3 °C/min). Body condition was scored from 1–5 and was noted to be low in March (1.93 ± 0.07) due to feeding practices and increased by June (2.93 ± 0.05) after dietary corrections were made. A concomitant increase (p < 0.05) in plasma total testosterone concentration and sperm motility was noted between March (8.0 ± 7.2 ng/mL, 5.71 ± 2.77%) and June (97.3 ± 11.3 ng/mL, 51.4 ± 14.3%). Samples cryopreserved using a modified slow freeze method (~−3 °C/min) had higher post-thaw motility and plasma membrane integrity than conventionally cryopreserved samples. Data indicate that southern stingray sperm morphometrics adheres to those of other elasmobranch species and that a slow cooling rate may be an avenue of research to improve southern stingray sperm survival during cryopreservation.

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Perinatal outcomes after ART with transfer of cryopreserved embryos

Journal of obstetrics and women s diseases ◽

10.17816/jowd62148-54 ◽

2013 ◽

Vol 62 (1) ◽

pp. 48-54

Author(s):

Yana Nikolayevna Kravchuk ◽

Alla Stanislavovna Kalugina

Keyword(s):

Perinatal Outcomes ◽

Slow Freezing ◽

Embryo Cryopreservation ◽

Number Of Children ◽

Freezing Method ◽

Article Analysis ◽

Cryopreservation Method ◽

Cryopreserved Embryos

The number of children born after ART, which includes cryopreservation methods, is steadily rising worldwide. Data on perinatal outcomes after transfer of cryopreserved embryos is presented in the article. Analysis of the influence of fertilization method — IVF/ICSI, embryo cryopreservation method — slow freezing method and vitrification is composed.

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