Cryo letters最新文献

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.

Background: Increased cooling and warming rates by using a suitable cryodevice allows the use of lower cryoprotectant concentration and reduces cryoinjuries as a result of the rapid passage through the 'dangerous' temperature zone.

Objective: To evaluate the effectiveness of newly customized strip pulled straw (SPS) with respect to post warming quality, viability, and in vitro maturation for immature oocytes post-vitrification of.

Materials and methods: SPS was prepared using conventional French mini straw to combine the merits of OPS and the Cryotop system. Immature sheep oocytes were treated in 15% EG + 15% DMSO, loaded on SPS and plunged into liquid nitrogen (LN). Post thaw quality, viability, and maturation rates of oocytes were determined after 1 week storage in LN.

Results: SPS achieved a post-thaw morphological survival of 90.9% with 9.0% morphological defects, 96.4% viability and 51% in vitro maturation. In comparison to OPS, SPS had higher post thaw survival (86.5% vs 67.9%) and maturation rate (57.7% vs 50.5%) with lower morphological defects (13.5% vs 32.1%). Cumulus cell loss was the highest among morphological abnormalities of post warm oocytes in SPS (40.9%) and OPS (44.1%). The data showed acceptable post thaw survival, viability and in vitro maturation rate of immature ovine oocytes using SPS as compared to traditional OPS.

Conclusion: SPS can be used as a cost effective alternative device for oocyte vitrification. Doi: 10.54680/fr23410110212.

Background: Podophyllum hexandrum is a highly endangered valuable medicinal plant of the Himalayas belonging to family Berberidaceae. This plant needs conservation efforts due to the over-exploitation and unscrupulous harvesting from the wild because of its ever-increasing demand.

Objective: To establish a long-term cryopreservation method for Podophyllum hexandrum using two techniques: Vitrification and V Cryo-plate.

Materials and methods: Zygotic embryos were cryopreserved using vitrification and V cryo-plate by optimization of parameters including preculture time, loading time and PVS2 dehydration time. Recovery of zygotic embryos was performed on different regrowth media for plantlet formation.

Results: With V cryo-plate, 90% regrowth was obtained as compared to 73.3% with vitrification. V Cryo-plate conditions were pre-culture of zygotic embryos in 0.3 M sucrose for 4 days, treatment in loading solution with 0.8 M sucrose for 20 min, dehydration in PVS2 for 50 min, LN exposure, unloading in 1.2 M sucrose for 20 min and transfer of zygotic embryos to regrowth medium for recovery. During recovery, the maximum number of shoots (4.2) and highest shoot length (5.1 cm) were observed on regrowth medium with 1.5 mg per liter BAP and 0.1 mg per liter IAA (R7).

Conclusion: Zygotic embryos of Podophyllum hexandrum were cryopreserved with 90% regrowth using a V cryoplate technique and plantlets were produced directly after cryopreservation. Doi: 10.54680/fr23410110712.

Background: The atypical seed storage behaviour reported in several orchid species justifies cryopreservation as a complementary conservation strategy to conventional seed banking.

Objective: This study aimed to assess the seed cryopreservation potential of five orchid species; two tropical epiphytic, Indonesian species (Dendrobium strebloceras, D. lineale), one temperate epiphytic, New Zealand species (D. cunninghamii) and two temperate terrestrial, New Zealand species (Pterostylis banksii, Thelymitra nervosa).

Materials and methods: Seeds were cryopreserved by direct immersion in liquid nitrogen (LN) and through the application of a cryoprotectant vitrification method. For the latter, seeds were exposed to Plant Vitrification Solution 2 (PVS2) for 0, 20, 50, and 70 min, at either room temperature or on ice, prior to immersion in LN.

Results: Seeds of all the studied species germinated well following direct cooling in LN. There was no difference in the seedling development capability between cryopreserved and non-cryopreserved seeds of both tropical epiphytic species and direct immersion in LN enhanced seed germination and shoot formation in both temperate terrestrials.

Conclusion: Through a range of analyses of germination and post-germination growth, our study shows the potential for cryopreserving epiphytic or terrestrial orchids from tropical and temperate regions. Doi: 10.54680/fr23410110312.

Cryopreservation has been used over many decades for the maintenance of viable biological specimens. Its expansion into the area of fertility preservation has been a natural outcome of the increased risks to human fertility from diseases, such as cancer and its treatment protocols, including radiation and chemo-therapy, and the general lifestyle trend to later marriages. The use of assisted reproductive techniques (ART) in preserving fertility have benefitted significantly from new scientific approaches, such as cryostorage, in which live cells and tissues are stored at low temperatures and revived when necessary. This review focuses on "cryopreservation science monitoring in reproductive biomedicine" to evaluate knowledge, trends, driving forces, impetus, and emerging technologies in order to draw a future roadmap for this field. Our analysis of the field of cryobiology emphasizes the significance of strategic planning of cryobiology research to support more its extensive use in therapeutics in the future. The Royan Institute (Tehran, Iran) recognises this need and has developed a strategic plan to engage in multidisciplinary research on the application of cryobiology, including cryobioengineering, in disease mitigation. We hoped that this study can help improve the quality and quantity of public discourse and expert awareness of the role for cryopreservation in fertility preservation within ART. DOI: 10.54680/fr23410110112.

Background: Persian walnut (Juglans regia L.) is one of the most economically important nut crops. In the Western Tien Shan in Kazakhstan, walnut forests are the northernmost in the natural range of this species. Shoot tip cryopreservation is an important strategy to ensure long-term clonal conservation of plant genetic resources.

Objective: To determine the effect of cold acclimation duration (0-6 weeks) with alternating temperatures (8 h at 22 degree C, light intensity 10 μmol m^-2 s^-1/16 h at -1 degree C, in the dark) and of plant vitrification solution 2 (PVS2) exposure duration (30, 50, 80 or 100 min) on shoot tip regrowth after cryopreservation by vitrification.

Materials and methods: In vitro-grown shoots of three wild Juglans regia accessions from a native population of Sairam-Ugam National Natural Park in the south of Kazakhstan and of cultivar Milotai 10 were used as sources of plant material. Shoot tips (1.8-2.0 mm with five to six leaf primordia) were excised from in vitro-grown shoots and cryopreserved using PVS2 vitrification technique.

Results: Regrowth of cryopreserved shoot tips increased and was significantly higher (P < 0.05) after 4-6 weeks cold acclimation with the highest regrowth between 59.9-67.8 degree after 5 weeks for the four genotypes tested. The highest regrowth level was obtained after 80 min of PVS2 exposure, which was significantly better (P < 0.05) compared to 30, 50 or 100 min exposure.

Conclusion: The PVS2 vitrification protocol established is very effective for cryopreservation of both unique wild J. regia germplasm and of walnut cultivars. Doi: 10.54680/fr23410110612.