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ABSTRACT ARCHIVE |
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CryoLetters is a bimonthly, international journal for low temperature science and technology |
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CryoLetters 32 (1), 1-12 (2011) STUDY ON THE MITOCHONDRIAL ACTIVITY AND MEMBRANE POTENTIAL AFTER EXPOSING LATER STAGE OOCYTES OF TWO GORGONIAN CORALS (JUNCEELLA JUNCEA AND JUNCEELLA FRAGILIS) TO CRYOPROTECTANTS S. Tsai3, E. Spikings2, I.C. Huang1 and C. Lin1* 1National museum of Marine Biology & Aquarium, 2 Houwan Road, Checheng, Pingtung, 944, Taiwan. Abstract Coral reefs provide a valuable habitat for many economically valuable fish and invertebrates. However, they are in serious jeopardy, threatened by increasing over-exploitation, pollution, habitat destruction, disease and global climate change. Here, we examined the effect of cryoprotectant exposure on mitochondrial activity and membrane potential (ΔΨm) in coral oocytes in order to find suitable cryoprotectants towards their successful cryopreservation. According to the No Observed Effect Concentrations (NOECs), methanol was found to be the least toxic cryoprotectant whilst DMSO was the most toxic cryoprotectant. The results also demonstrated that there were no significant differences (p > 0.05) in ATP concentrations between Junceella juncea and Junceella fragilis after exposure to all concentrations of all cryoprotectants for 30 min. Using confocal microscopy, JC-1 (5,50,6,60-tetrachloro-1,10,3,30-tetraethyl-imidacarbocyanine iodide) staining indicated that the mitochondrial membrane potential of Junceella fragilis oocytes reduced after 1 M and 2 M methanol treatment and a loss of the mitochondrial distribution pattern and poor green fluorescence after 3M methanol treatment. Therefore, even oocytes that show no adverse effect of cryoprotectants on survival might suffer some more subtle impacts. The results obtained from this study will provide a basis for development of protocols to cryopreserve the oocytes of gorgonian corals. Keywords: gorgonian coral, oocyte, mitochondrial membrane potential, cryoprotectants
CryoLetters 32 (1), 13-20 (2011) HISTONE DEACETYLTRANSFERASE1 EXPRESSION IN MOUSE OOCYTE AND THEIR IN VITRO-FERTILIZED EMBRYO: EFFECT OF OOCYTE VITRIFICATION Jun-Jie Li1,2#, Yan Pei1# , Guang-Bin Zhou1, Lun Suo1, Yan-Ping Wang1, Guo-Quan Wu1, Xiang-Wei Fu1, Yun-Peng Hou1 and Shi-En Zhu1* 1College of Animal Science and Technology, State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing, 100193, P.R.China. Abstract This study was conducted to investigate the expression of Histone Deacetyltransferase1 (HDAC1) in mouse embryos derived from the vitrified-warmed oocytes. Firstly, the mouse oocytes at metaphaseII (MII) stage were randomly allocated into three groups: A untreated (control), B exposed to vitrfication solution (VS) without being plunged into liquid nitrogen (toxicity), or C vitrified by open-pulled straw(OPS) method (vitrification). After warming, they were fertilized in vitro. Fresh oocytes were used as control. Expression of HDAC1 was then examined in MII mouse oocytes and embryos by immunofluorescence with anti-HDAC1 polyclonal antibody and fluorescein isothiocyanate-conjugated goat anti-rabbit IgG. Results showed that after in vitro fertilization (IVF), developmental rates to two-cell embryos (38.52%), 4-cell embryos (35.25%), morula (31.97%) and blastocysts (26.23%) in cryopreserved oocytes were all significantly lower than those of fresh oocytes (P <0.01). In addition, HDAC1 expression in the vitrified group was significantly lower (P<0.05) than that in the control and toxicity groups at all developmental stages except for the blastocyst. Moreover, the vitrified-warmed oocytes showed significantly lower (P<0.05) HDAC1 expression compared with that of control and toxicity groups. In conclusion, HDAC1 was expressed both in oocytes and in their in vitro-fertilized embryos. This decreased expression of HDAC1 in mouse oocytes and the embryos due to the cryopreservation may have a negative impact on embryo development. Keywords: OPS Vitrification, Oocyte, Early Embryo, Histone Deacetyltransferase 1, Mouse
CryoLetters 32 (1), 21-27 (2011) Uniformity trials in plant freezing assays involving microtitre plates Dimitris Zaragotas1 and Elias Anastassopoulos2* 1Department of Forestry and Management of Natural Environment, Technological Educational Institute of Larissa (Karditsa), 43100 Karditsa, Greece. Abstract The primary aim of this study was to measure the inherent experimental variability in plant freezing assays involving microtitre plates. Laurus nobilis leaf strips were used as experimental material. Data analysis involved variability measurements among and within microtitre plates. Statistically significant variability (p < 0.05) was observed in both cases. The second aim was to test the effectiveness of five experimental designs, in controlling the experimental error. According to our results the variability in microtitre plate freezing assays can be controlled by the use of blocked experimental designs and single well plots. Keywords: uniformity trial, experimental design, microtitre plate, freezing assay, plant, high-throughput screening, Laurus nobilis.
CryoLetters 32 (1), 28-39 (2011) The EFFECTS OF DESICCATION AND EXPOSURE TO CRYOGENIC TEMPERATURES ON EMBRYONIC AXES OF landolphia kirkii Provain Kistnasamy, Patricia Berjak* and N.W. Pammenter School of Biological and Conservation Sciences, University of KwaZulu-Natal (Westville Campus), Durban, South Africa Abstract The present study reports on the effects of rapid dehydration, chemical cryoprotectants and various cooling rates on survival, assessed by the ability for both root and shoot development, of embryonic axes excised with a small portion of each cotyledon, from mature, recalcitrant seeds of Landolphia kirkii. All axes withstood rapid (flash) drying to a water content of c. 0.28 g g-1 (dry mass basis); however, the use of chemical cryoprotectants before flash drying was lethal. Rapid cooling rates were detrimental to axes flash-dried to 0.28 g g-1, reducing survival to 10% and 0% after exposure to -196C and -210C, respectively. Ultrastructural examination revealed that decompartmentation and loss of cellular integrity were associated with viability loss after rapid cooling to cryogenic temperatures, although lipid bodies retained their morphology. Hence, lipid crystallisation was not implicated in cell death following dehydration, exposure to cryogenic temperatures and subsequent rewarming and rehydration. Cooling at 1C min-1 facilitated survival of 70% of axes with attached cotyledonary segments at 0.28 g g-1 after exposure to -70C, with 45% viability retention when further cooled at 15C min-1 to -180C. However, no axes excised without attached cotyledonary segments produced shoots after cryogenic exposure. The use of slow cooling rates is promising for cryopreservation of mature axes of L. kirkii, but only when excised with a portion of each cotyledon left attached. Keywords: cooling rate, cryopreservation, dehydration, excision damage, Landolphia kirkii, lipid body, recalcitrant
CryoLetters 32 (1), 1-12 (2011) STUDIES ON CRYOPROTECTANT TOXICITY TO ZEBRAFISH (Danio rerio) OVARIAN TISSUE FRAGMENTS S. Anil, F. Ghafari, T. Zampolla, D. M. Rawson and T. Zhang* LIRANS Institute of Research in the Applied Natural Sciences, University of Bedfordshire, 250 Butterfield, Great Marlings, Luton, Bedfordshire, LU2 8DL, UK Abstract Cryopreservation of ovarian tissue is a viable alternative to cryopreservation of oocytes and embryos in many species but it has not been studied in fish. Selection of cryoprotectant is an important step in designing cryopreservation protocols. In order to identify the optimum cryoprotectant (CPA) in a suitable concentration for zebrafish ovarian tissue cryopreservation, studies on toxicities of five commonly used cryoprotectants methanol, ethanol, dimethyl sulfoxide (DMSO), ethylene glycol (EG) and propylene glycol (PG) were carried out. Experiments were conducted on ovarian tissue fragments consisting of stage I and stage II ovarian follicles. Ovarian tissue fragments were incubated in 90% L-15 medium (pH 9) containing 1-4M cryoprotectants for 30min at 22°C. Three different tests were used to assess ovarian tissue fragment viability: trypan blue (TB) staining, fluorescein diacetate (FDA) combined with propidium iodide (PI) staining and adenosine 5´- triphosphate (ATP) assay. Results from these tests showed that ATP assay was more sensitive than FDA+PI or TB staining for assessing cryoprotectant toxicity to follicles in tissue fragments. Methanol and ethanol were the least toxic cryoprotectants tested. Cryoprotectant toxicity increased in the order of methanol/ethanol, DMSO, PG and EG. Ethanol was used for zebrafish ovarian tissue for the first time and the results showed that the effect of methanol and ethanol on ovarian tissue fragments were comparable. As methanol has been shown to be the most effective cryoprotectant for zebrafish ovarian follicles in our laboratory, the use of ethanol will also be considered in assisting future freezing protocol design. The present study also showed that stage II ovarian follicles are more sensitive to cryoprotectant treatment than stage I follicles in tissue fragments. The results obtained in this study provided useful information for ovarian tissue fragment cryopreservation protocol design in the future. Keywords: zebrafish (Danio rerio), ovarian tissue fragments, cryopreservation, cryoprotectants, TB, FDA-PI, ATP assay
CryoLetters 32 (1), 51-56 (2011) SHEEP OVARIAN TISSUE VITRIFICATION BY TWO DIFFERENT DEHYDRATION PROTOCOLS AND NEEDLE IMMERSING METHODS Rouhollah Fathi1, Mojtaba Rezazadeh Valojerdi1, 2*, Hussein Eimani1, Fatemeh Hasani1, Poopak Eftekhari Yazdi1, Zahra Ajdari1 and Leila Sadat Tahaei1
1Department of Embryology, Infertility and IVF Unit, Royan Institute, East Hafez Ave., Bani Hashem Sq., Resalat St., P.O. Box 19395-4644, Tehran, Iran Abstract The present research investigated the effects of two vitrification methods on sheep ovarian tissue. The base medium (BM) of the vitrification solutions contains 60% HEPES tissue culture medium (HTCM), 15% ethylene glycol (EG) and 15% dimethyl sulfoxide (DMSO). Ovarian cortex pieces were dehydrated by two different regimens, the 2-step which consisted of 50% BM and a 90% solution of 0.25 mol/L sucrose in BM for 10 minutes each at 4˚C and the 4-step method which utilized: a) 25% BM, b) 50% BM, c) 75% BM and d) a 90% solution of 0.25 mol/L sucrose in BM for 5 minutes each at 4˚C. After warming, the proportion of intact antral follicles in the control (non-vitrified) and 2-step vitrification groups was significantly higher than in the 4-step vitrification group. The number of apoptotic follicles in the ovarian pieces was significantly different between the control and 4-step vitrification groups. These results indicated that sheep ovarian tissue vitrification by the 2-step method was simpler and more effective than the 4-step method. Keywords: vitrification, dehydration, sheep ovary
CryoLetters 32 (1), 57-61 (2011) Cryopreservation of GOLDFISH CAUDAL FIN EXPLANTS USING GLYCEROL AS a CRYOPROTECANT Casiano H. Choresca Jr.1, Dennis K. Gomez3, Ji Hyung Kim1, Jee Eun Han1, Sang Phil Shin1, Byeong Chun Lee2* and Se Chang Park1* 1Laboratory of Aquatic Animal Medicine, College of Veterinary Medicine, Seoul National University, Seoul 151-742, South Korea Abstract The objective of this study was to investigate the effect of glycerol on the cryopreservation fin explants of goldfish, Carassius auratus. Four different concentrations, 5, 10, 15, and 20% (v/v) of glycerol and a control were tested. These were prepared in Dulbecco’s modified Eagle’s medium with 20% (v/v) Fetal Bovine Serum. Attachment and outgrowing rates were monitored from day 3 to day 14. Results showed that fin explants cryopreserved in 20% concentration of glycerol was significantly higher (P<0.05) with a 100% attachment rate compared to 5, 10, and 15% concentrations with 36.67, 84.19 and 86.51% attachment rate, respectively. Fin explants cryopreserved in 20% glycerol concentration also had significantly higher (P<0.05) outgrowth of cells (72.50%) than the other three concentrations on day 3. Moreover, a 100% outgrowth of cells in all concentrations was achieved after 14 days of culture. No attachment and out growth of cells were observed in control group. Goldfish caudal fin explants cryopreserved in glycerol can produce live cells efficiently, regardless of concentration. Keywords: caudal fin, cryopreservation, fish explants, glycerol, goldfish
CryoLetters 32 (1), 62-68 (2011) ASEPTIC MINIMUM VOLUME VITRIFICATION TECHNIQUE FOR PORCINE PARTHENOGENETICALLY ACTIVATED BLASTOCYST Lin Lin1, 2, 3, *, Yutao Du3, Xiuqing Zhang3, Huanming Yang3, Lars Bolund2, Henrik Callesen1 and Gábor Vajta1 1Institute of Genetics and Biotechnology, Faculty of Agricultural Sciences, Aarhus University, DK-8830 Tjele, Denmark Abstract Minimum volume vitrification may provide extremely high cooling and warming rates if the sample and the surrounding medium contacts directly with the respective liquid nitrogen and warming medium. However, this direct contact may result in microbial contamination. In this work, an earlier aseptic technique was applied for minimum volume vitrification. After equilibration, samples were loaded on a plastic film, immersed rapidly into factory derived, filter-sterilized liquid nitrogen, and sealed into sterile, pre-cooled straws. At warming, the straw was cut, the filmstrip was immersed into a 39°C warming medium, and the sample was stepwise rehydrated. Cryosurvival rates of porcine blastocysts produced by parthenogenetical activation did not differ from control, vitrified blastocysts with Cryotop. This approach can be used for minimum volume vitrification methods and may be suitable to overcome the biological dangers and legal restrictions that hamper the application of open vitrification techniques. Keywords: pig, sterile, embryo, oocyte, chilling, storage
CryoLetters 32 (1), 69-80 (2011) STRUCTURAL, ULTRASTRUCTURAL AND FUNCTIONAL STUDIES OF HUMAN CARDIAC VALVE ALLOGRAFTS THAT SUFFERED AN INCREMENT OF THE CRYOSTORAGE TEMPERATURE Victoria Bessone1, María D. Pizarro2, María F. Izaguirre3, María E. Biancardi1, Graciela Furno4, Norberto Baumgartner5, Joaquín V. Rodríguez2,6 and Alejandra B. Quintana1* 1Morfología, 6Farmacología, Departamento de Ciencias Fisiológicas, 4Estadística, Departamento de Matemáticas y Estadística; Facultad de Ciencias Bioquímicas y
Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531- S2002LRK Rosario, Argentina. Abstract Human cardiac valve allografts (HVAs) suffer injuries during the cryopreservation period. Here, we described structural, ultrastructural and functional damages suffered by HVAs after an increment of their cryostorage temperature (100ºC). Two experimental groups of pulmonary and aortic HVAs were compared: cryopreserved (HVAcryo) and cryopreserved with temperature changes (HVAΔT). Transmission electron microscopy (TEM) was used to analyze valve fibroblasts and extracellular matrix morphology. Total collagen amount was estimated using two different methods and fibroblast viability was assessed measuring their oxygen consumption rate. Porcine heart grafts valves were used to set the techniques. Disorganized collagen network was seen in HVAΔT by TEM. Fibroblasts showed damages in the cellular membrane and many secretor vesicles. Mitochondria and chromatin were also altered. HVAΔT had less amount of collagen and fibroblasts showed an oxygen consumption rate markedly diminished compared to HVAcryo. The increment of 100ºC suffered by HVAs caused damages that made them unsuitable for clinical purposes. Keywords: human heart valve allografts, cardiac valve fibroblasts, cryopreservation, collagen, fibroblast oxygen consumption rate.
CryoLetters 32 (1), 81-88 (2011) CRYOPRESERVATION OF UMBILICAL CORD BLOOD-DERIVED MESENCHYMAL STEM CELLS WITHOUT DIMETHYL SULFOXIDE Hai-Yan Wang1, Zhao-Rong Lun2 and Shu-Shen Lu1,* 1School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China. Abstract Cryopreservation of umbilical cord blood-derived mesenchymal stem cells (UCB-derived MSCs) is crucial step for its clinical applications in cell transplantation therapy. In the cryopreservation of MSCs, dimethyl sulfoxide (Me2SO) has been widely used as a cryoprotectant (CPA). However, it has been proved that Me2SO has toxic side effects to human body. In this study, Me2SO-free CPA solutions which contained ethylene glycol (EG), 1, 2-propylene glycol (PG) and sucrose as basic CPAs, supplemented with polyvinyl alcohol (PVA) as an additive, were developed for the cryopreservation of UCB-derived MSCs. The cryopreservation of UCB-derived MSCs was achieved by vitrification via plunging into liquid nitrogen and by programmed freezing via an optical-DSC system respectively. The viability of thawed UCB-derived MSCs was tested by trypan blue exclusion assay. Results showed that the viability of thawed UCB-derived MSCs was enhanced from 71.2% to 95.4% in the presence of PVA for vitrification, but only < 10.0% to 44.8% of viability was found for programmed freezing. These results indicate that PVA exerts a beneficial effect on the cryopreservation of UCB-derived MSCs and suggest the vitrification in combination with the Me2SO-free CPA solutions supplemented with PVA would be an efficient protocol for the cryopreservation of UCB-derived MSCs. Keywords: Cryopreservation, mesenchymal stem cell, vitrification, PVA |
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For Abstracts published from meetings, such as SLTB meetings, go to the
relevant Volume Year of the journal (above). For Full text Free Access Content (from 2000 onwards) go to CryoLetters at Ingenta and look for the blue symbol. |
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