1 Department of Biological Sciences, University of New Orleans and Audubon Center for Research of Endangered Species, New Orleans LA 70131, 2 Tulane Regional Primate Research Center, Covington LA 70433, 3 California Regional Primate Research Center, Davis, CA 95617, USA and 4 Department of Biology, University of York, York YO10 5YW, UK
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Abstract |
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Key words: oocytes/osmotic shock sensitivity/permeability characteristics/rhesus monkey
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Introduction |
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The cryopreservation of oocytes of non-human primates would offer several advantages. First, it would permit the accumulation of oocytes for studies that require large numbers of oocytes to be used simultaneously. Since rhesus monkeys are seasonal breeders, cryopreservation of their oocytes would remove the barrier of reproductive seasonality and allow their use year-round. Cryopreservation of oocytes could also be used to preserve the germplasm of genetically valuable animals, such as a specific animal with unusual immunological characteristics. The same method might be used for endangered species of non-human primates. Furthermore, cryopreservation of non-human primate oocytes could serve as a model for human oocytes.
Despite the potential importance of such a method, only two reports of attempts to cryopreserve oocytes of non-human primates have been madeone with squirrel monkeys (DeMayo et al., 1985; Saimiri spp.) and the other with oocytes of an infertile lowland gorilla (Lanzendorf et al., 1992
; Gorilla gorilla). In both cases, conventional equilibrium freezing with a relatively low concentration of cryoprotectant was used to cryopreserve oocytes. With oocytes of squirrel monkeys, although 50% of the cryopreserved oocytes appeared to be morphologically intact, maturation and fertilization rates were significantly reduced (DeMayo et al., 1985
). With those of a gorilla, six immature oocytes were cryopreserved in 1.5 mol/l propylene glycol by cooling them at 0.5°C/min to 80°C before plunging them into liquid nitrogen; two oocytes appeared morphologically intact after being thawed, but their developmental competency was compromised (Lanzendorf et al., 1992
).
Several factors affect survival of oocytes when they are cryopreserved (Van Blerkom, 1991; Parks and Ruffing, 1992
; Critser et al., 1997
; Parks, 1997
; Shaw et al., 2000
). During cryopreservation, in addition to being subjected to subzero temperatures and phase changes of the suspending media, the oocyte must tolerate a sequence of volume excursions. First, it is exposed to an hypertonic solution of a cryoprotective agent (CPA); this causes the oocyte to contract osmotically as intracellular water flows out of the cell because of differences in water activity between the intra- and extracellular compartments. As the CPA diffuses across the plasma membrane, the cell regains its original isotonic volume as water re-enters the cell. The cell undergoes yet another volume change during freezing. As ice crystals form outside the cell, differences in water activity between intra- and extracellular solutions occur, causing the cell to dehydrate (Mazur, 1970
). Finally, the cell undergoes another volume excursion during warming and removal of the cryoprotectant from the cell. If these volume excursions exceed the limit tolerated by oocytes, cell damage may occur as a consequence of osmotic shock, as has been shown to occur in zygotes, embryos and other types of cells (Leibo, 1986
, 1992
; Arnaud and Pegg, 1990
; Oda et al., 1992
).
There appears to be only one reported study on permeability characteristics of non-human primate oocytes (Younis et al., 1996). These authors noted that oocytes of the cynomolgus monkey (Macaca fascicularis) behaved as a perfect osmometer, and that the osmotically inactive cell volumes of germinal vesicle-stage and metaphase II (MII) oocytes were 20 and 10% respectively. Using a cryo-microscope, these authors also determined the ice nucleation parameters and calculated the hydraulic conductivity and its activation energy of cynomolgus oocytes at subzero temperatures.
In the present study, the osmotic behaviour and permeability of oocytes of rhesus monkeys (Macaca mulatta) to three CPAs was determined. Previous studies have shown that rhesus oocytes, like those of the human, are sensitive to chilling injury, in that the meiotic spindle undergoes disassembly when oocytes are exposed to 0°C for >1 min (Zenzes et al., 2001; Songsasen et al., 2002
). Even transient cooling to room temperature has been shown to alter human oocytes (Pickering et al., 1990
). To avoid possible damage to oocytes used in this study, their osmotic responses were measured at 30°C. The extreme chilling sensitivity of rhesus oocytes suggests that their successful cryopreservation might require that they be vitrified or cooled very rapidly in order to circumvent injury resulting from exposure for several minutes to temperatures near 0°C, as occurs during equilibrium cooling. However, high concentrations of CPAs, such as those commonly used for cryopreservation by vitrification or rapid cooling methods, render oocytes extremely susceptible to osmotic injury. Therefore, the sensitivity of rhesus oocytes to osmotic shock was also determined. Oocytes were collected from female monkeys that had received HCG to induce resumption of meiosis; such oocytes are the most developmentally competent that can be obtained from the rhesus monkey (Schramm and Bavister, 1999
). This study was predicated on the assumption that determination of permeability characteristics and osmotic shock sensitivity would aid in the derivation of a procedure to cryopreserve rhesus oocytes.
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Materials and methods |
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Animals, superovulation treatment and oocyte retrieval
Adult female rhesus monkeys (Macaca mulatta; ages ranging from 6 to 16 years) used in the present study were housed at the Tulane Regional Primate Research Center and maintained according to recommendations of the Guide for the Care and Use of Laboratory Animals [U.S. Department of Health and Human Service publication no. (NIH) 8523, revised 1985]. All procedures for handling and treatment of the animals were reviewed and approved in advance by the Animal Care and Use Committees of the Tulane Regional Primate Research Center, the University of New Orleans, and the Audubon Center for Research of Endangered Species. These committees also adhere to guidelines of the U.S. Department of Agriculture.
Monkeys were individually caged in rooms with a 06:00 to 18:00 light cycle at a temperature maintained at 2527°C, were fed twice daily a diet of Purina monkey chow, and provided with water ad libitum. Animals were monitored daily in the morning, and those that exhibited menses received twice-daily i.m. injections of 37.5 IU of recombinant human FSH (rhFSH; Serono Laboratories, Norwell, MA, USA) for 78 days beginning on day 1 or 2 of the menstrual cycle (day 1 = first day of menstruation). Ovaries were examined on day 5 or 6 after 4 days of FSH injections by ultrasonography of sedated monkeys in order to evaluate their follicular response to gonadotrophin. To induce oocyte maturation, a single i.m. injection of 1000 IU of recombinant HCG (rHCG; Serono Laboratories) was given on day 8 or 9 to those monkeys that had responded to rhFSH.
Oocyte aspirations were conducted under strict aseptic conditions. For oocyte collections, females were sedated with acepromazine maleate (0.2 mg/kg body weight) and glycopyrrolate (0.01 mg/kg body weight), anaesthetized with ketamine hydrochloride (10 mg/kg body weight), intubated and maintained on a mixture of isoflurane/oxygen (1.5%) during the procedure. Oocytes were aspirated laparoscopically at 2732 h after the injection of rHCG from follicles >3 mm in diameter, using a 20-gauge spinal needle. After aspiration, oocytes were placed into warm Tyrode's lactate-pyruvate-HEPES medium (TALP-HEPES; Parrish et al., 1988) containing 10 IU/ml heparin. After surgery, the monkeys were given injections of buprenorphine (0.1 mg/kg body weight) as an analgesic for 3 days.
Although rHCG was given to the females to induce resumption of meiosis, the meiotic status of oocytes used in this study ranged from the germinal vesicle stage to MII. In the present study, oocytes were considered to be at one of only two stages: mature oocytes were those that had extruded their first polar body; immature oocytes were those at any stage of meiosis prior to the MII stage. No attempt was made to separate immature oocytes into various categories of maturation, as meiotic status can be determined definitively only after oocytes have been fixed and stained.
A total of 219 oocytes obtained from 11 females undergoing 14 treatment cycles was used in this study. Cumulusoocyte complexes (COC) were recovered from the aspirated fluids using a stereomicroscope and transported in TALP-HEPES medium at 37°C from Covington LA to the laboratory in New Orleans (approximately a 1.5 h drive) in a MinitübTM portable incubator (Minitüb, Verona, WI, USA). Considerable care was exercised to ensure that the oocytes were maintained at 37°C from the time of collection until their use. In all experiments, oocytes were handled in a room maintained at 30°C. Upon arrival at the laboratory, the COC were placed into TALP-HEPES medium containing 1.5% (w/v) hyaluronidase (Type IV-S from bovine testes) at 30°C for 2 min, and cumulus cells were partially removed by gently pipetting the oocytes a few times. It must be emphasized that cumulus cells were only removed to the point where the oocytes could be visualized in order to avoid the possibility of altering the properties of the oocyte membranes by lengthy exposure to the enzyme. The oocytes were washed three times in TALP-HEPES medium, and then subjected to various treatments as described below.
Determination of the osmotically inactive volume of rhesus oocytes
Three mature and three immature oocytes from two rhesus females were used for these measurements. After cumulus cells had been removed, the oocytes were exposed sequentially to 0.2, 0.5, 0.75, 1.0 and 1.5 mol/l solutions of sucrose (500 to 3000 mOsm) prepared in TALP-HEPES medium for 5 min in each solution at 30°C. The osmolality of each solution was measured using a calibrated vapour pressure osmometer (VAPROTM, Model 5520; Wescor, Inc., Logan, UT, USA). Individual oocytes were transferred into 10 µl droplets of isotonic TALP-HEPES under mineral oil and photographed using a digital camera (Coolpix 950; Nikon Instruments Inc., Lewisville, TX, USA) attached to an inverted microscope (Nikon TE300; Nikon Instruments, Inc.). The oocytes were then rinsed in 2.5 ml of the first hypertonic solution (0.2 mol/l sucrose in TALP-HEPES) and then quickly transferred into a 10 µl droplet of the same solution under oil. After an oocyte had been allowed to equilibrate for 5 min, it was photographed. After being sequentially exposed to the other hypertonic solutions and being photographed, the change in cross-sectional area of each oocyte in each solution was measured. The equilibrium cell volume of oocytes in each hypertonic solution was calculated using the following equation:
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Permeability characteristics of rhesus oocytes
A total of 24 oocytes collected on separate occasions from four females was used in this experiment. Permeability characteristics of rhesus oocytes in 1.0 mol/l solutions of dimethylsulphoxide (DMSO), ethylene glycol (EG) and glycerol were assessed at 30°C using a method modified from a previously reported technique (Jackowski et al., 1980). On each occasion, 10 µl drops of TALP-HEPES medium and of 1.0 mol/l solutions of DMSO (n = 9 oocytes), EG (n = 10 oocytes) and of glycerol (n = 5 oocytes) overlaid by mineral oil were prepared in Nunclon multiwell dishes (Fisher Scientific, Pittsburgh, PA, USA) and held at 30°C. Individual oocytes were washed in 2.5 ml TALP-HEPES and then quickly placed into a 10 µl drop of the same solution and photographed. Subsequently, the same oocyte was then rinsed briefly in 2.5 ml of a given CPA and immediately placed into a 10 µl drop of the same CPA for 10 min (120 min for glycerol). Oocytes were photographed at 0.5, 1, 2, 3, 4, 5 and 10 min after being exposed to a given CPA. Their cross-sectional areas after exposure to CPAs were measured, and changes in the relative volumes of oocytes were calculated as described above. These volume changes were plotted as a function of the duration of exposure to CPA.
On a separate occasion, the diameters of four metaphase II oocytes were measured, using an eyepiece micrometer that had been calibrated with a Nikon stage micrometer. The mean and standard error of the mean were calculated. For calculation of the permeability to CPAs, the measured volumes were fitted to a two-parameter model defined by the following equations (Kleinhans, 1998):
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Osmotic sensitivity of rhesus oocytes
A total of 189 oocytes from 12 females was used in this experiment. The experiment was divided into two parts. In the first part, oocytes (n = 109, six replicates) were exposed to 0.1 to 2.0 mol/l solutions of EG in TALP-HEPES, whilst in the second part of the experiment, oocytes (n = 80, six replicates) were exposed to 2.0 to 5.0 mol/l solutions of EG. In both experiments, some oocytes were exposed only to TALP-HEPES as dilution controls.
The procedure to determine osmotic sensitivity consisted of the following steps. Oocytes were pipetted into 0.1 ml TALP-HEPES contained in 12x75 mm plastic tubes (Falcon®, Fisher Scientific) that were placed into a 30°C water bath. Then, 0.1 ml volumes of 0.2, 0.8, 1.2, 1.6, 2.0 or 4.0 mol/l EG were added to the plastic tubes, yielding final concentrations of 0.1, 0.4, 0.6, 0.8, 1.0 and 2.0 mol/l EG. After 5 min, all oocytes were rapidly diluted with TALP-HEPES (11-fold dilution) by adding 2.0 ml TALP-HEPES to the plastic tubes. The diluted oocytes were recovered and cultured in CMRL1066 medium (Life Technologies, Grand Island, NY, USA) + 20% fetal bovine serum (Life Technologies) at 37°C for 60 min. The purpose of this brief incubation at 37°C was to allow damaged oocytes to degenerate. A similar procedure was performed in the second part of the experiment, except that the oocytes were exposed to solutions of 2.0, 3.0, 4.0 or 5.0 mol/l EG and allowed to equilibrate for 5 or 10 min at 30°C before dilution. The rationale of using two exposure periods was to determine the effect of equilibration times on the survival of oocytes after dilution.
Survival in both parts of the experiment as judged by membrane integrity of oocytes was assessed using Live/Dead stain® (Molecular Probes, Inc., Eugene, OR, USA) that contains two nucleic acid dyes, SYBR14 and propidium iodide. The staining procedure was modified from that described for bovine spermatozoa (Garner et al., 1994). Briefly, an oocyte was placed into a 10 µl droplet of 0.02 mmol/l solution of SYBR14 in TALP-HEPES for 5 min at 37°C. The oocyte was then counterstained with 1 µl of 2.4 mmol/l propidium iodide in water and incubated for an additional 5 min at 37°C, before being examined under a fluorescence microscope.
Statistical analysis
Regression analysis (SigmaStat, version 2.0; SPSS Inc., Chicago, IL, USA) was performed on the volumetric responses of rhesus oocytes exposed to increasing concentrations of sucrose. Comparison of relative volumes of oocytes after exposure to different cryoprotectants for a given time was performed using Student's t-test (SigmaStat). Comparison of the percentage of oocytes that remained membrane-intact after being exposed to various concentrations of EG was conducted using a 2-test (Instat version 3.00 for Windows 95; Graphpad Software, San Diego, CA, USA; www.graphpad.com). The level of significance was set at 5%.
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Results |
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Discussion |
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Although NaCl solutions have been commonly used for studies of the osmotic behaviour of oocytes of many species (Leibo, 1980; Hunter et al., 1992
; Ruffing et al., 1993
; Benson and Critser, 1994
), solutions of mono- and disaccharides can also be used effectively for the determination of osmotic behaviour of human and mouse oocytes (McWilliams et al., 1995
). The use of saccharides for this purpose eliminates the deleterious effects observed when oocytes/embryos are exposed to very concentrated electrolyte solutions (Mazur and Schneider, 1986
). In the present study, the disaccharide sucrose was used to determine the osmotic behaviour of rhesus monkey oocytes. As has been observed with other mammalian species, Boylevan't Hoff plots showed that rhesus oocytes behaved as `perfect osmometers' over a wide range of osmolalities. Extrapolation of the Boylevan't Hoff plots to infinite osmolality for immature and mature oocytes yielded osmotically inactive volumes of 20 and 17% respectively. The value for immature oocytes agreed very well with the 20% volume determined for germinal vesicle-stage oocytes of cynomolgus monkeys (Younis et al., 1996
). It should be noted that the latter authors exposed oocytes to hypertonic solutions of NaCl, whereas the non-electrolyte, sucrose, was used in the present study.
The osmotically inactive volume obtained in the present study was similar for both immature and mature rhesus oocytes. These results differ from those reported for other stages of bovine and cynomolgus monkey oocytes. For example, one group (Ruffing et al., 1993) reported that the osmotically inactive volume of immature bovine oocytes was 32%, while that of mature oocytes was 24%. In both of these studies (Ruffing et al., 1993
; Younis et al., 1996
), immature oocytes consisted only of germinal vesicle-stage oocytes. However, in the present study, oocytes considered to be immature were all oocytes that had not extruded the first polar body, as they were obtained from females that had been treated with HCG to induce resumption of meiosis.
Permeability to water and its activation energy are among the principal determinants of the response of all types of cells to freezing and thawing (Mazur, 1970; Leibo, 1986
). Coefficients of water permeability have been determined for oocytes of mice (Leibo 1980
; Hunter et al., 1990
, 1992
; Benson and Critser, 1994
; Paynter et al., 1997
, 1999a
), hamsters (Benson and Critser, 1994
), rats (Agca et al., 2000
), cattle (Myers et al., 1987
; Ruffing et al., 1993
; Agca et al., 1998
), goats (Le Gal et al., 1994
, 1995
), humans (Hunter et al., 1990
, 1992
; Newton et al., 1999
; Paynter et al., 1999b
, 2001
) and cynomolgus monkeys (Younis et al., 1996
). Although a review of permeability properties of oocytes from many species has been published (Critser et al., 1997
), to our knowledge there have been no reports on rhesus monkey oocytes.
In general, the responses of rhesus monkey oocytes to cryoprotectants were similar to those of oocytes of other species. The oocytes initially shrank when they were exposed to an hypertonic solution and reached a minimum volume within 1 min. Thereafter, the oocytes re-expanded as the cryoprotectant entered the cell, accompanied by water uptake. None of the oocytes that was exposed to glycerol shrank isotropically; thus, their volumetric changes could not be measured. However, it is clear that glycerol moved across the plasma membrane of rhesus oocytes very slowly. The oocytes partially regained their isotonic volume, but did not reach equilibrium even after exposure to glycerol for 120 min. This result was similar to that reported for mouse oocytes (Jackowski et al., 1980). These differences suggest that the permeability characteristics of a given cell type, e.g. oocytes, may vary among species.
Seven of 10 oocytes exposed to EG contracted isotropically, and five of nine oocytes exposed to DMSO did so. Irregular shrinkage of oocytes after exposure to cryoprotectants has also been observed in other species (Hunter et al., 1990; Ruffing et al., 1993
; Le Gal et al., 1995
). Exposure of mouse oocytes to 1.5 mol/l DMSO caused depolymerization of microfilaments, which was associated with disruption of the actin network and alteration of the cell surface (Vincent et al., 1990a
). However, mouse oocytes have been found to tolerate exposure to 4.0 to 8.0 mol/l EG for 5 min without any visible alteration of microfilaments (Hotamisligil et al., 1996
). Unlike mouse oocytes, rabbit oocytes and zygotes seem to tolerate exposure to DMSO, since exposure to this cryoprotectant did not cause depolymerization of actin (Vincent et al., 1989
, 1990b
). The effects of cryoprotectants on the organization of the cytoskeleton of macaque oocytes have previously been studied using glycerol, but not DMSO or EG (Younis et al., 1996
). The latter authors showed that exposure of cynomolgus oocytes to glycerol resulted in depolymerization of F-actin around the cortex of oocytes. It is speculated therefore that DMSO and EG might also affect the organization of microfilaments of rhesus oocytes, which in turn may cause the plasma membrane of some oocytes to collapse upon exposure to these cryoprotectants.
Oocytes exposed to 1.0 mol/l DMSO reached equilibrium after 5 min, whereas those exposed to EG required 10 min to return to their initial isotonic volume. This result was similar to that described for bovine oocytes at 22°C (Agca et al., 1998), although these authors reported differences between germinal vesicle stage and MII oocytes. In that study, osmotic responses of germinal vesicle-stage oocytes suggested that they were more permeable to DMSO than MII oocytes, whereas the opposite was true for oocytes in EG. Substantial differences in permeability characteristics between mature and immature oocytes have also been observed in the goat (Le Gal et al., 1994
) and rat (Agca et al., 2000
). In the present study, no significant differences were found in permeability responses between mature and immature oocytes. This was most likely due to the small number of oocytes that contracted spherically and could be assessed. There was no clear evidence that cumulus cells surrounding oocytes were responsible for these differences. As shown in Figure 2
, oocytes in Figure 2A
were surrounded by fewer cumulus cells than those in Figures 2C and 2E
; all three oocytes had not extruded the polar body. However, the oocytes in Figures 2C and 2E
had contracted spherically, whereas that in Figure 2A
had not. Moreover, even among oocytes of the same meiotic stage there was a large variation in their responses to exposure to DMSO and EG (Figures 3 and 4
). Thus far, it has not been possible to identify factors that may have contributed to differences in permeability responses among individual oocytes, though this may well be due to the genetic heterogeneity of rhesus monkeys used. As shown in a previous report for bovine oocytes (Ruffing et al., 1993
), sizeable differences exist among the osmotic responses of individual oocytes, suggesting that there may be considerable variation in permeability characteristics among oocytes of all species other than inbred strains of mice. Among outbred ICR mice, it has been reported that, although there was no significant variability within animals, the water permeability of oocytes collected from different females differed significantly (Benson and Critser, 1994
). In contrast, the water permeability of oocytes from different females of the genetically homogeneous hybrid strain, B6D2F1, did not differ significantly (Leibo, 1980
).
In the present study, the osmotic responses of rhesus oocytes were measured only at 30°C. Previous studies had shown rhesus oocytes to be very sensitive to chilling injury (Songsasen et al., 2002); hence it was concluded provisionally that the successful cryopreservation of these oocytes would require them to be cooled at high rates in order to circumvent any injury that might result from exposure to temperatures near 0°C for several minutes, as occurs during standard methods of equilibrium cooling. This suggests that mathematical modelling of the response of rhesus oocytes when cooled to subzero temperatures by equilibrium cooling is unlikely to yield a practicable procedure, as such a method would inevitably expose oocytes to damaging temperatures near 0°C for more than 1 min.
After having determined the hydraulic conductivity of several rhesus oocytes, these values were compared with those values reported previously. The mean value of Lp for immature and mature rhesus oocytes was 1 µm/min/atm at 30°C (see Table I
). In order to make a comparison, values for human oocytes of 0.43 µm/min/atm at 3°C (McGrath et al., 1995
) and 0.78 µm/min/atm at 22°C (Newton et al., 1999
) were used, together with a value for cynomolgus monkey oocytes of 0.23 µm/min/atm at 0°C (Younis et al., 1996
). (In the latter report, Lp was given as 3.8x1014 m3/N/s; although not specified, the reference temperature was 0°C; M.Toner and A.I.Younis, personal communication.)
As had been performed for rhesus oocytes in the present study, both groups (McGrath et al., 1995; Newton et al., 1999
) had determined Lp values for human oocytes exposed to DMSO. In all these cases, observations had been made at a single temperature; hence, in order to make this comparison an Arrhenius plot was constructed (Figure 7
) in which the solid line is the calculated regression of the four values indicated by the solid points. The open symbols are the values for human oocytes determined by others (Paynter et al., 1999b
, 2001
), and these were not used for the regression calculation. The fact that the four independent measurements yielded a straight line suggests that they were consistent with each other. The Arrhenius plot yields an activation energy of 6.85 kcal/mol for Lp of primate oocytes. Recent determinations of Lp values for human oocytes in the presence of DMSO and propylene glycol yielded respective activation energies of 15 kcal/mol and 11 kcal/mol (Paynter et al., 1999b
,2001
). Although there were discrepancies in the activation energy for Lp between primate oocytes (human and rhesus monkey) plotted in the present study and that reported previously for human oocytes (Paynter et al., 1999b
, 2001
), these values were lower than those of 23.52 and 22.48 kcal/mol reported for mouse oocytes in the presence of DMSO and propylene glycol respectively (Paynter et al., 1999a
). In the present study, the Lp of rhesus oocytes in the presence of DMSO was 0.96 µm/min/atm, which was higher than 0.64 µm/min/atm for mouse oocytes measured at the same temperature. When comparing the Lp and activation energy values for the two species, it was concluded that, in the presence of DMSO, rhesus oocytes appeared to be more permeable to water than did mouse oocytes.
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In the present study, the permeability responses and sensitivity to osmotic shock of rhesus oocytes were determined. Rhesus oocytes were similar to oocytes of other species in that they behaved as a perfect osmometer; moreover, they appeared rather impermeable to glycerol but permeable to DMSO and EG. The results obtained in the present study should aid in the development of a method by which may rhesus oocytes be cryopreserved.
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Acknowledgements |
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Notes |
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References |
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Agca, Y., Liu, J., Critser, E.S. and Critser, J.K. (2000) Fundamental cryobiology of rat immature and mature oocytes: hydraulic conductivity in the presence of Me2SO, Me2SO permeability, and their activation energies. J. Exp. Zool., 286, 523533.[ISI][Medline]
Al-Hasani, S., Kirsch, J., Diedrich, J., Blanke, S., van der Ven, H. and Krebs, D. (1989) Successful embryo transfer of cryopreserved and in-vitro fertilized rabbit oocytes. Hum. Reprod., 4, 7779.[Abstract]
Arav, A., Shehu, D. and Mattioli, M. (1993) Osmotic and cytotoxic study of vitrification of immature bovine oocytes. J. Reprod. Fertil., 99, 353358.[Abstract]
Arnaud, F.G. and Pegg, D.E. (1990) Permeation of glycerol and propane-1,2-diol into human platelets. Cryobiology, 27, 107118.[ISI][Medline]
Benson, C.T. and Critser, J.K. (1994) Variation of water permeability (Lp) and its activation energy (Ea) among unfertilized golden hamster and ICR murine oocytes. Cryobiology, 31, 215223.[ISI][Medline]
Bernard, A. and Fuller, B.J. (1996) Cryopreservation of human oocytes: a review of current problems and perspectives. Hum. Reprod. Update, 2, 193207.[Abstract]
Chen, C. (1986) Pregnancy after human oocyte cryopreservation. Lancet, ii, 884886.
Critser, J.K., Agca, Y. and Gunasena K.T. (1997) The cryobiology of mammalian oocytes. In Karow, A.M. and Critser, J.K. (eds), Reproductive Tissue Banking: Scientific Principles. Academic Press, San Diego, pp. 329358.
DeMayo, F.J., Rawlins, R.G. and Dukelow, W.R. (1985) Xenogenous and in vitro fertilization of frozen/thawed primate oocytes and blastomere separation of embryos. Fertil. Steril., 43, 295300.[ISI][Medline]
Friedler, S.C., Giudice, L.C. and Lamb, E.J. (1988) Cryopreservation of embryos and ova. Fertil. Steril., 49, 743764.[ISI][Medline]
Garner, D.L., Johnson, L.A., Yue, S.T., Roth, B.L. and Haugland, R.P. (1994) Dual DNA staining assessment of bovine sperm viability using SYBR-14 and propidium iodide. J. Androl., 15, 620629.
Hotamisligil, S., Toner, M. and Powers, R.D. (1996) Changes in membrane integrity, cytoskeletal structure, and developmental potential of murine oocytes after vitrification in ethylene glycol. Biol. Reprod., 55, 161168.[Abstract]
Hunter, J.E., Bernard, A.G., Fuller, B.J. and Shaw, R.W. (1990) The osmotic response of human and mouse oocytes following cooling: evidence of altered morphological characteristics. Cryo-Letter, 11, 307314.
Hunter, J.E., Bernard, A., Fuller, B.J., McGrath, J.J. and Shaw, R.W. (1992) Measurement of the membrane water permeability (Lp) and its temperature dependence (activation energy) in human fresh and failed-to-fertilize oocytes and mouse oocytes. Cryobiology, 29, 240249.[ISI][Medline]
Jackowski, S., Leibo, S.P. and Mazur, P. (1980) Glycerol permeabilities of fertilized and unfertilized mouse ova. J. Exp. Zool., 212, 329341.[ISI]
Kleinhans, F.W. (1998) Membrane permeability modeling: Kedem-Ketchalsky vs. a two-parameter formalism. Cryobiology, 37, 271289.[ISI][Medline]
Lanzendorf, S.E., Holmgren, W.J., Schaffer, N., Hatasaka, H., Wentz, A.C. and Jeyendran, R.S. (1992) In vitro fertilization and gamete micromanipulation in the lowland gorilla. J. Assist. Reprod. Genet., 9, 358364.[ISI][Medline]
Le Gal, F., Gasqui, P. and Renard, J.P. (1994) Differential osmotic behavior of mammalian oocytes before and after maturation: a quantitative analysis using goat oocytes as a model. Cryobiology, 31, 154170.[ISI][Medline]
Le Gal, F., Gasqui, P. and Renard, J.P. (1995) Evaluation of intracellular cryoprotectant concentration before freezing goat oocytes. Cryo-Letters, 16, 312.[ISI]
Leibo, S.P. (1980) Water permeability and its activation energy of fertilized and unfertilized mouse ova. J. Membr. Biol., 53, 179188.[ISI][Medline]
Leibo, S.P. (1986) Preservation of mammalian embryos. In Evans, J.W. and Hollaender, A. (eds), Genetic Engineering of Animals: An Agriculture Perspective. Plenum Press, New York, pp. 251272.
Leibo, S.P. (1992) Techniques for preservation of mammalian germ plasm. Anim. Biotech., 3, 139153.
Ludwig, M., Al-Hasani, S., Felberbaum, R. and Diedrich, K. (1999) New aspects of cryopreservation of oocytes and embryos in assisted reproduction and future perspectives. Hum. Reprod., 14 (Suppl. 1), 162185.
Martino, A., Songsasen, N. and Leibo, S.P. (1996) Development into blastocysts of bovine oocytes cryopreserved by ultra-rapid cooling. Biol. Reprod., 54, 10591069.[Abstract]
Mazur, P. (1970) Cryobiology: the freezing of biological systems. Science, 168, 939949.[ISI][Medline]
Mazur, P. and Schneider, U. (1986) Osmotic responses of preimplantation mouse and bovine embryos and their cryobiological implications. Cell Biophys., 8, 259285.[ISI][Medline]
McGrath, J.J., Fuller, B.J., Hunter, J.E., Paynter, S. and Bernard, A.G. (1995) The permeability of fresh pre-ovulatory human oocytes to dimethyl sulfoxide at 3°C. Cryo-Letters, 16, 7984.[ISI]
McWilliams, R.B., Gibbons, W.E. and Leibo, S.P. (1995) Osmotic and physiological responses of mouse zygotes and human oocytes to mono- and disaccharides. Hum. Reprod., 10, 11631171.[Abstract]
Myers, S.P., Lin, T.-T., Pitt, R.A. and Steponkus, P.L. (1987) Cryobehavior of immature bovine oocytes. Cryo-Letters, 8, 260275.[ISI]
Newton, H., Pegg, D.E., Barrass, R. and Gosden, R.G. (1999) Osmotically inactive volume, hydraulic conductivity and permeability to dimethyl sulphoxide of human mature oocytes. J. Reprod. Fertil., 117, 2733.[Abstract]
Oda, K., Gibbons, W.E. and Leibo, S.P. (1992) Osmotic shock of fertilized mouse ova. J. Reprod. Fertil., 95, 737747.[Abstract]
Parks, J.E. (1997) Hypothermia and mammalian gametes. In: Karow, A.M. and Critser, J.K. (eds), Reproductive Tissue Banking: Scientific Principles. Academic Press, San Diego, pp. 229261.
Parks, J.E. and Ruffing, N.A. (1992) Factors affecting low temperature survival of mammalian oocytes. Theriogenology, 37, 5379.
Parrish, J.J., Susko-Parrish, J., Winer, M.A. and First, N.L. (1988) Capacitation of bovine sperm by heparin. Biol. Reprod., 38, 11711180.[Abstract]
Paynter, S.J., Fuller, B.J. and Shaw, R.W. (1997) Temperature dependence of mature mouse oocyte membrane permeabilities in the presence of cryoprotectant. Cryobiology, 34, 122130.[ISI][Medline]
Paynter, S.J., Fuller, B.J. and Shaw, R.W. (1999a) Temperature dependence of Kedem-Katchalsky membrane transport coefficients for mature mouse oocytes in the presence of ethylene glycol. Cryobiology, 39, 169176.[ISI][Medline]
Paynter, S.J., Cooper, A., Gregory, L., Fuller, B.J. and Shaw, R.W. (1999b) Permeability characteristics of human oocytes in the presence of the cryoprotectant dimethylsulfoxide. Hum. Reprod., 14, 23382342.
Paynter, S.J., O'Neil, L., Fuller, B.J. and Shaw, R.W. (2001) Membrane permeability of human oocytes in the presence of the cryoprotectant propane-1,2-diol. Fertil. Steril., 75, 532538.[ISI][Medline]
Pegg, D.E., Hunt, C.J. and Fong, L.P. (1987) Osmotic properties of the rabbit corneal endothelium and their relevance to cryopreservation. Cell Biophys., 10, 169191.[ISI][Medline]
Pickering, S.J., Braude, P.R., Johnson, M.H., Cant, A. and Currie, J. (1990) Transient cooling to room temperature can cause irreversible disruption of the meiotic spindle in the human oocyte. Fertil. Steril., 54, 102108.[ISI][Medline]
Rall, W.F. (1987) Factors affecting the survival of mouse embryos cryopreserved by vitrification. Cryobiology, 24, 387402.[ISI][Medline]
Ruffing, N.A., Steponkus, P.L., Pitt, R.E. and Parks, J.E. (1993) Osmotic behavior, hydraulic conductivity, and incidence of intracellular ice formation in bovine oocytes at different developmental stages. Cryobiology, 30, 562580.[ISI][Medline]
Schramm, R.D. and Bavister, B.D. (1999) A macaque model for studying mechanisms controlling oocyte development and maturation in human and non-human primates. Hum. Reprod., 14, 25442555.
Schroeder, A.C., Champlin, A.K., Mobraaten, L.E. and Eppig, J.J. (1990) Developmental capacity of mouse oocytes cryopreserved before and after maturation in vitro. J. Reprod. Fertil., 89, 4350.[Abstract]
Shaw, J.M., Oranratnachai, A. and Trounson, A.O. (2000) Fundamental cryobiology of mammalian oocytes and ovarian tissue. Theriogenology, 53, 5972.[ISI][Medline]
Songsasen, N., Yu, I., Ratterree, M.S., VandeVoort, C.A. and Leibo, S.P. (2002) Effect of chilling on organization of tubulin and chromosomes in rhesus monkey oocytes. Fertil. Steril., 77, 818825.[ISI][Medline]
Vajta, G., Holm, P., Kuwayama, M., Booth, P.J., Jacobsen, H., Greve, T. and Callesen, H. (1998) Open pulled straw (OPS) vitrification: a new way to reduce cryoinjuries of bovine ova and embryos. Mol. Reprod. Dev., 51, 5358.[ISI][Medline]
Van Blerkom, J. (1991) Cryopreservation of the mammalian oocyte. In: Pedersen, R.A., McLaren, A. and First, N.L. (eds), Animal Applications of Research in Mammalian Development. Cold Spring Harbor Laboratory Press, New York, pp. 83119.
van Uem, J.F., Siebzehnrübl, E.R., Schuh, B., Kock, R., Trotnov, S. and Lang, N. (1987) Birth after cryopreservation of unfertilized oocytes. Lancet, i, 752753.
Vincent, C., Garnier, V., Heyman, Y. and Renard, J.P. (1989) Solvent effects on cytoskeletal organization and in-vivo survival after freezing of rabbit oocytes. J. Reprod. Fertil., 87, 809820.[Abstract]
Vincent, C., Pickering, S.J., Johnson, M.H. and Quick, S.J. (1990a) Dimethylsulfoxide affects the organisation of microfilaments in mouse oocytes. Mol. Reprod. Dev., 26, 227235.[ISI][Medline]
Vincent, C., Pruliere, G., Pajot-Augy, E., Campion, E., Garnier, V. and Renard, J.P. (1990b) Effects of cryoprotectants on actin filaments during the cryopreservation of one-cell rabbit embryos. Cryobiology, 27, 923.[ISI][Medline]
Whittingham, D.G. (1977) Fertilization in vitro and development to term of unfertilized mouse oocytes previously stored at 196°C. J. Reprod. Fertil., 49, 8994.[Abstract]
Younis, A.I., Toner, M., Albertini, D.F. and Biggers, J.D. (1996) Cryobiology of non-human primate oocytes. Hum. Reprod., 11, 156165.[Abstract]
Zenzes, M.T., Bielecki, R., Casper, R.F. and Leibo, S.P. (2001) Effects of chilling to 0°C on the morphology of meiotic spindles in human metaphase II oocytes. Fertil. Steril., 75, 769777.[ISI][Medline]
Submitted on January 3, 2002; accepted on March 22, 2002.