The hypothesis that addition and removal of cryoprotectants to and from spermatozoa would initiate regulatory volume decrease, and lead to osmolyte loss and reduced sperm function, was tested. Common cryoprotectants, ...The hypothesis that addition and removal of cryoprotectants to and from spermatozoa would initiate regulatory volume decrease, and lead to osmolyte loss and reduced sperm function, was tested. Common cryoprotectants, in the absence of freezing and thawing, affected bovine ejaculated spermatozoa by lowering their total and progressive motility in medium, reducing their migration through surrogate cervical mucus, damaging sperm head membranes and inducing sperm tail coiling. Sperm function was slightly better maintained after cryoprotectants were added and removed in multiple small steps rather than in a single step. The intracellular content of the polyol osmolytes, D-sorbitol and myo-inositol, exceeded that of the zwitterion osmolytes, L-carnitine and L-glutamate. Certain cryoprotectants reduced intracellular L-camitine and L-glutamate concentration but not that of myo-inositol or D-sorbitol. Multistep treatments with some cryoprotectants had advantages over one-step treatments in mucus penetration depending on the original amount of intracellular camitine and glutamate in the spermatozoa. Overall, sperm quality was best maintained by multistep treatment with glycerol and propanediols that were associated with decreased intracellular glutamate concentration. Bovine spermatozoa seem to use glutamate to regulate cryoprotectant-induced cell swelling.展开更多
The aim of the present study was to investigate the efficiency of the encapsulation-dehydration technique for cryopreservation of Cyrtopodium hastchbachii Pabst seeds.Immature seeds of this species were cryopreserved ...The aim of the present study was to investigate the efficiency of the encapsulation-dehydration technique for cryopreservation of Cyrtopodium hastchbachii Pabst seeds.Immature seeds of this species were cryopreserved by an encapsulation-dehydration technique.Seeds of five immature pods,120 days after pollination,were encapsulated in 3%calcium alginate matrix and pretreated in liquid medium supplemented with 0.08 M sucrose(24 h),0.15 M sucrose(24 h),0.25 M sucrose(48 h),0.5 M sucrose(24 h)and 0.75 M sucrose(24 h)in shaker at 60 rpm.Alginate beads were dehydrated 5 h in silicagel and immersed in liquid nitrogen for 12 h.Cryopreserved beads were thawed at 30℃ for 1 min,rehydrated using the same liquid mediums[0.75 M sucrose(24 h),0.5 M sucrose(24 h),0.25 M sucrose(48 h)and 0.15 M sucrose(24 h)]and cultivated in half strength Murashige&Skoog medium(1962)with the addition of 2 g/L activated charcoal.Sixty four percent of seeds survived and developed into acclimatized plants after being cryopreserved.In this work,the encapsulation-dehydration technique was employed for first time in Cyrtopodium hatschbachii.展开更多
文摘The hypothesis that addition and removal of cryoprotectants to and from spermatozoa would initiate regulatory volume decrease, and lead to osmolyte loss and reduced sperm function, was tested. Common cryoprotectants, in the absence of freezing and thawing, affected bovine ejaculated spermatozoa by lowering their total and progressive motility in medium, reducing their migration through surrogate cervical mucus, damaging sperm head membranes and inducing sperm tail coiling. Sperm function was slightly better maintained after cryoprotectants were added and removed in multiple small steps rather than in a single step. The intracellular content of the polyol osmolytes, D-sorbitol and myo-inositol, exceeded that of the zwitterion osmolytes, L-carnitine and L-glutamate. Certain cryoprotectants reduced intracellular L-camitine and L-glutamate concentration but not that of myo-inositol or D-sorbitol. Multistep treatments with some cryoprotectants had advantages over one-step treatments in mucus penetration depending on the original amount of intracellular camitine and glutamate in the spermatozoa. Overall, sperm quality was best maintained by multistep treatment with glycerol and propanediols that were associated with decreased intracellular glutamate concentration. Bovine spermatozoa seem to use glutamate to regulate cryoprotectant-induced cell swelling.
基金Faculty of Agricultural Sciences(UNNE)SGCyT-UNNE(General Secretariat of Science and Technology UNNE)for financial support.
文摘The aim of the present study was to investigate the efficiency of the encapsulation-dehydration technique for cryopreservation of Cyrtopodium hastchbachii Pabst seeds.Immature seeds of this species were cryopreserved by an encapsulation-dehydration technique.Seeds of five immature pods,120 days after pollination,were encapsulated in 3%calcium alginate matrix and pretreated in liquid medium supplemented with 0.08 M sucrose(24 h),0.15 M sucrose(24 h),0.25 M sucrose(48 h),0.5 M sucrose(24 h)and 0.75 M sucrose(24 h)in shaker at 60 rpm.Alginate beads were dehydrated 5 h in silicagel and immersed in liquid nitrogen for 12 h.Cryopreserved beads were thawed at 30℃ for 1 min,rehydrated using the same liquid mediums[0.75 M sucrose(24 h),0.5 M sucrose(24 h),0.25 M sucrose(48 h)and 0.15 M sucrose(24 h)]and cultivated in half strength Murashige&Skoog medium(1962)with the addition of 2 g/L activated charcoal.Sixty four percent of seeds survived and developed into acclimatized plants after being cryopreserved.In this work,the encapsulation-dehydration technique was employed for first time in Cyrtopodium hatschbachii.
