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RESEARCH |
Chugai Research Institute for Medical Science, Inc., 1-135 Komakado, Gotemba, Shizuoka, 412-8513 Japan
Correspondence should be addressed to Kou-ichi Jishage; Email: jishagekui{at}chugai-pharm.co.jp
| Abstract |
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| Introduction |
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Ovaries from young mice that have been dissected and halved are cryopreserved by either the equilibrium freezing method (Cox et al. 1996, Gunasena et al. 1997, Sztein et al. 1998, 1999, Candy et al. 2000, Shaw & Trounson 2002) or the vitrification method (Kagabu & Umezu 2000, Takahashi et al. 2001, Migishima et al. 2003). Recently, a new cryopreservation method for 10-day-old mouse ovaries by vitrification was reported (Migishima et al. 2003) using DAP213 (Nakagata 1989), a combination of the cryoprotectants dimethyl sulfoxide (DMSO), acetamide and propanediol in concentrations of 2, 1 and 3 mol/l respectively. It is the first report on the vitrification of whole ovaries. Additionally, this method has had a high success rate in mouse production via ovary transplantation. However, the viability of vitrified-warmed adult mouse ovaries is still unknown for this method.
In the present study, we investigated the viability of mouse ovaries of various ages after vitrification and the potential of this technology as a method for the preservation of female germ cells.
| Materials and Methods |
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Ovary cryopreservation and warming
Ovaries isolated from the 4-week-, 10-week- and 7-month-old mice were cut into fourths (about 1 mm3) to approximate the size of the ovaries of a 10-day-old mouse (Fig. 1
). The ovaries were cryopreserved by vitrification with DAP213 (2 mol/l DMSO, 1 mol/l acetamide and 3 mol/l propanediol in PBI medium (Whittingham 1974)), as described by Migishima et al.(2003). Isolated ovaries were pretreated with 40 µl of 1 mol/l DMSO in PBI medium at room temperature for 5 min. This step was repeated twice. The ovaries were then transferred into 1 ml cryotubes (Nalge Nunc International KK, Tokyo, Japan) containing 5 µl of 1 mol/l DMSO in PBI medium. The cryotubes were placed in a 0 °C Labtop cooler (Nalge Nunc International KK, Tokyo, Japan) for 5 min. Then 95 µl DAP213 kept at 0 °C were added to each cryotube, and the cryotubes were placed in the 0 °C Labtop cooler for 5 min. After exposure to DAP213, the cryotubes were plunged directly into liquid nitrogen and stored. For warming, cryotubes containing the samples kept in liquid nitrogen were diluted with PBI medium containing 0.25 mol/l sucrose kept at 37 °C. The recovered ovaries were transferred to the PBI medium for washing twice and then transferred to Whittens medium before transplantation.
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Statistical analyses
Data presented in this study were analyzed statistically by the chi-square test and Tukey test for nonparametric multiple comparisons. In all statistical tests, a difference was considered significant when the two-tailed P value was < 0.05.
All mice were housed in a controlled environment of light/dark (light 05001900 h), temperature (24 ± 1 °C), and humidity (50% ± 10%) with free access to standard laboratory chow (CE-2; CLEA Japan). The Animal Care and Use Committee of Chugai Pharmaceutical (Shizuoka, Japan) reviewed the protocols and confirmed that the animals used in the present study were cared for and used humanely.
| Results |
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| Discussion |
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Although GFP-positive pups were obtained from all vitrified-warmed donor ovaries examined in this study, the percentages of GFP-positive pups among the total pups delivered from recipients were lower than from fresh ovaries in all combinations of recipient age and donor age (Tables 1
and 2
). These data indicate that vitrification and warming the ovaries reduced their viability, consistent with the results Migishima et al.(2003) reported, using ovaries from 10-day-old, immature mice as grafts. This tendency showed especially when 4-week-, 10-week- and 7-month-old mice were used as donors (Tables 1
and 2
). It is possible that the wide range of developmental stages of follicles in adult mouse ovaries is one of the causes of this tendency. Previous reports describing ovarian histology after freeze-thawing concluded that large mature follicles are more affected by freezing injuries and small immature follicles have a higher survival rate (Parrot 1960, Smith 1961, Gosden 1992, Harp et al. 1994, Cox et al. 1996, Candy et al. 1997). The number of large follicles that survive after freeze-thawing has been estimated to be about 5% of the total surviving follicles (Green et al. 1956). Additionally, analysis of the effect of cryoprotectants on follicle survival after freezing demonstrated that 8194% of primordial follicles survived when DMSO was used as the cryoprotectant (Candy et al. 1997). In spite of a reduction in the number of donor-derived pups, the present results indicate that follicles in adult mouse ovaries are viable even after vitrification and develop normally after orthotopic transplantation into recipients. Additionally, GFP-positive pups were born to recipients transplanted with ovaries from 7-month-old donors without normal estrous cyclicity for at least 7 consecutive days, whether the ovaries of donors were fresh or cryopreserved. Therefore, it seems that follicles in ovaries from mice without normal estrous cyclicity also have the capability to develop normally even after vitrification and warming. However, further studies are required to elucidate the involvement of estrous cyclicity.
The most efficient reproduction was observed in 4-week-old recipients transplanted with fresh ovaries from 4-week-old donors with an efficiency rate nearly threefold higher than that of 10-week-old recipients transplanted with fresh ovaries from 4-week-old donors (Fig. 2
). However, there was no significant difference in reproductive efficiency between 4- and 10-week-old recipients transplanted with fresh ovaries from 10-week-old donors. In recipients transplanted with fresh ovaries from 10-day- and 4-week-old donors, the percentage of GFP-positive pups among the total pups delivered from 4-week-old recipients was significantly higher than from 10-week-old recipients (Table 1
). Additionally, GFP-positive pup birthrate per three litters of 4-week-old recipients transplanted with fresh ovaries from 4-week-old donors maintained a rate higher than that of 10-week-old recipients transplanted with fresh ovaries from 4-week-old donors. And recipients transplanted with ovaries from 10-day-, 10-week- and 7-month-old donors had almost the same birthrate whether the recipients were 4- or 10-week-old mice (Fig. 3
). This suggests that 10-week-old recipients may have some negative effects on fresh ovarian grafts from 10-day- and 4-week-old donors. Thus, 4-week-old mice would be more suitable recipients for producing young via fresh ovary transplantation.
The above-mentioned negative effects of fresh ovarian grafts of young mice were not seen in 10-week-old recipients transplanted with vitrified-warmed ovaries (Fig. 4
). Migishima et al.(2003) reported no difference between the percentages of donor ovarian oocytes among total oocytes collected from recipients transplanted with fresh ovaries and recipients transplanted with vitrified-warmed ovaries; however, the number of oocytes collected per recipient transplanted with vitrified-warmed ovaries was about one-third that per recipient transplanted with fresh ovaries. If the ovaries of donors are affected by cryopreserving injuries, the percentage of donor ovarian oocytes of total oocytes collected from recipients transplanted with vitrified-warmed ovaries would be lower than from recipients transplanted with fresh ovaries. Thus, cryoprotectants remaining in the ovarian tissue after warming and washing might have some effect on the recipients locally or systemically as well as on the viability of the graft itself. The reduced pregnancy rate for recipients with vitrified-warmed ovaries may also have been a result of such effects (Table 2
).
Both adult and immature mouse ovaries cryopreserved by vitrification with DAP213 are viable for producing young, and follicles in ovaries of adult mice without normal estrous cyclicity also have the capability to develop normally even after vitrification and warming. Our results indicate that cryopreservation of mouse ovaries by vitrification with DAP213 is a useful method for preservation of female germ cells from mice at various ages. However, after a second litter, few pups were delivered from ovaries of donors from recipients transplanted with vitrified-warmed ovaries from adult mice. Further studies are necessary to improve ovary cryopreservation by vitrification in order.
| Acknowledgements |
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| Footnotes |
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| References |
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Candy CJ, Wood MJ & Whittingham DG 1997 Effect of cryoprotectants on the survival of follicles in frozen mouse ovaries. Journal of Reproduction and Fertility 110 1119.
Candy CJ, Wood MJ & Whittingham DG 2000 Restoration of a normal reproductive life span after grafting of cryopreserved mouse ovaries. Human Reproduction 15 13001304.
Cox SL, Shaw JM & Jenkin G 1996 Transplantation of cryopreserved fetal ovarian tissue to adult recipients in mice. Journal of Reproduction and Fertility 107 315322.
Gosden RG 1992 Transplantation of fetal germ cells. Journal of Assisted Reproduction and Genetics 9 118123.[CrossRef][Web of Science][Medline]
Green SH, Smith AV & Zukermans S 1956 The number of oocytes in ovarian autografts freezing and thawing. Journal of Endocrinology 13 330334.
Gunasena KT, Villines PM, Critser ES & Critser KJ 1997 Live births after autologous transplant of cryopreserved mouse ovaries. Human Reproduction 12 101106.
Harp R, Leibach J, Black J, Keldahl C & Karow A 1994 Cryopreservation of murine ovarian tissue. Cryobiology 31 336343.[CrossRef][Medline]
Inoue K, Ogura A & Hayashi J 2002 Production of mitochondrial DNA transgenic mice using zygotes. Methods 26 358363.[CrossRef][Web of Science][Medline]
Kagabu S & Umezu M 2000 Transplantation of cryopreserved mouse, Chinese hamster, rabbit, Japanese monkey and rat ovaries into rat recipients. Experimental Animals 49 1721.[CrossRef][Web of Science][Medline]
Matzuk MM, Burns KH, Viveiros MM & Eppig JJ 2002 Intercellular communication in the mammalian ovary: oocytes carry the conversation. Science 296 21782180.
Migishima F, Suzuki-Migishima R, Song SY, Kuramochi T, Azuma S, Nishijima M & Yokoyama M 2003 Successful cryopreservation of mouse ovaries by vitrification. Biology of Reproduction 68 881887.
Nakagata N 1989 High survival rate of unfertilized mouse oocytes after vitrification. Journal of Reproduction and Fertility 87 479483.
Nakagata N 1996 Use of cryopreservation techniques of embryos and spermatozoa for production of transgenic (Tg) mice and for maintenance of Tg mouse lines. Laboratory Animal Science 46 236238.[Web of Science][Medline]
Nakagata N, Okamoto M, Ueda O & Suzuki H 1997 Positive effect of partial zona pellucida dissection on the in vitro fertilizing capacity of cryopreserved C57BL/6J transgenic mouse spermatozoa of low motility. Biology of Reproduction 57 10501055.[Abstract]
Okamoto M, Nakagata N, Ueda O, Kamada N & Suzuki H 1988 Cryopreservation of gene disrupted mouse spermatozoa. Journal of Mammalian Ova Research 15 7788.[CrossRef]
Parrot DM 1960 The fertility of mice with orthotopic ovarian grafts derived from frozen tissue. Journal of Reproduction and Fertility 1 230241.
Rall WF & Fahy GM 1985 Ice-free cryopreservation of mouse embryo at 196 degrees C by vitrification. Nature 313 573575.[CrossRef][Medline]
Richards JS, Jahnsen T, Hedin L, Lifka J, Ratoosh S, Durica JM & Goldring NB 1987 Ovarian follicular development: from physiology to molecular biology. Recent Progress in Hormone Research 43 231270.[Web of Science][Medline]
Shaw JM & Trounson AO 2002 Ovarian tissue transplantation and cryopreservation. Application to maintenance and recovery of transgenic and inbred mouse lines. In Transgenesis Techniques: Principles and Protocols, 2nd edn, Methods in Molecular Biology pp 229251. Ed. AR Clarke. Totowa, NJ: Humana Press.
Silva JP & Larsson NG 2002 Manipulation of mitochondrial DNA gene expression in the mouse. Biochimica et Biophysica Acta 1555 106110.[Medline]
Smith AU 1961 The viability of the frozen ovarian tissue. In Biological Effects of Freezing and Supercooling, pp 166196. Eds. H Barcroft, H Davinson & WDM Paton, London: Arnold.
Sztein JM, Sweet H, Farley J & Mobraaten LE 1998 Cryopreservation and orthotopic transplantation of mouse ovaries: new approach in gamete banking. Biology of Reproduction 58 10711074.
Sztein JM, McGregor TE, Bedigian HJ & Mobraaten LE 1999 Transgenic mouse strain rescue by frozen ovaries. Laboratory Animal Science 49 99100.[Web of Science][Medline]
Takahashi E, Miyoshi I & Nagasu T 2001 Rescue of a transgenic mouse line by transplantation of a frozen-thawed ovary obtained postmortem. Contemporary Topics in Laboratory Animal Science 40 2831.[Web of Science][Medline]
Whitten WK 1971 Embryo medium. Nutrient requirements for the culture of preimplantation embryos in vitro. Advances in the Biosciences 6 129141.
Whittingham DG 1974 Embryo banks in the future of developmental genetics. Genetics 78 395402.
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