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1.
T. OTOI N. KOYAMA K. YAMAMOTO N. HORIKITA S. TACHIKAWA T. SUZUKI 《Veterinary journal (London, England : 1997)》2000,159(3):392-286
Two-hundred-and-thirty-one fair-quality embryos at the compacted morula stage collected from 89 superovulated cows were cultured in TCM199 or Brinster's BMOC-3 medium with or without 100 microM beta-mercaptoethanol (beta-ME). After 24 h culture, a total of 142 fair-quality embryos developed to the blastocyst stage, of which 106 were subsequently frozen with 1.8 M ethylene glycol. The mean cell number and development rates of frozen-thawed blastocysts from the fair-quality embryos cultured in TCM199 containing beta-ME were higher than those of the fair-quality embryos directly frozen without culture. The pregnancy rates obtained with frozen blastocysts from fair-quality embryos tended to be lower than those of non-cultured fresh fair-quality embryos and cultured fresh blastocysts. These results indicate that the inclusion of beta-ME in pre-freezing culture media improve the development of frozen-thawed blastocysts from fair-quality embryos, but not the pregnancy rate. 相似文献
2.
Different factors affect developmental competence and cryotolerance in in vitro produced bovine embryo 总被引：1，自引：0，他引：1
Imai K Matoba S Dochi O Shimohira I 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(10):887-891
The present study was conducted to examine the effects of culture systems and culture media on developmental competence and freezability of bovine embryos obtained by in vitro culture of in vitro matured and fertilized (IVM-IVF) oocytes. No significant difference was observed in the proportions of oocytes developed to blastocysts, the speed at which the oocytes reached the blastocyst stage and the number of cells, when the IVM-IVF oocytes were cultured in CR1aa with or without cumulus cells. Nevertheless, more of the IVM-IVF oocytes cultured either with or without cumulus cells in CR1aa were seen to reach the blastocyst stage much sooner than those cultured with cumulus cells in TCM199 (P<0.05). The proportion of embryos developed to the blastocyst stage by day 7 in CR1aa culture was significantly higher than embryos cultured in TCM199. Viability after frozen-thawed blastocysts were obtained in vitro, was seen in a significantly higher percentage of embryos cultured in TCM199 and developed to the hatched blastocysts than in those cultured in CR1aa (P<0.05). These results indicate that CR1aa was superior to TCM199 for the potential developmental of IVM-IVF oocytes to blastocysts during in vitro culture regardless of co-culture with or without cumulus cells. But the freezability of blastocysts developed in CR1aa was inferior to those developed in TCM199. 相似文献
3.
In vitro development of OPU‐derived bovine embryos cultured either individually or in groups with the silk protein sericin and the viability of frozen‐thawed embryos after transfer 
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下载免费PDF全文 Tomohiro Isobe Yoshihisa Ikebata Lanh Thi Kim Do Fuminori Tanihara Masayasu Taniguchi Takeshige Otoi 《Animal Science Journal》2015,86(7):661-665
The optimization of single‐embryo culture conditions is very important, particularly in the in vitro production of bovine embryos using the ovum pick‐up (OPU) procedure. The purpose of this study was to examine the development of embryos derived from oocytes obtained by OPU that were cultured either individually or in groups in medium supplemented with or without sericin and to investigate the viability of the frozen‐thawed embryos after a direct transfer. When two‐cell‐stage embryos were cultured either individually or in groups for 7 days in CR1aa medium supplemented with or without 0.5% sericin, the rates of development to blastocysts and freezable blastocysts were significantly lower for the embryos cultured individually without sericin than for the embryos cultured in groups with or without sericin. Moreover, the rate of development to freezable blastocysts of the embryos cultured individually with sericin was significantly higher than that of the embryos cultured without sericin. When the frozen‐thawed embryos were transferred directly to recipients, the rates of pregnancy, abortion, stillbirth and normal calving in the recipients were similar among the groups, irrespective of the culture conditions and sericin supplementation. Our findings indicate that supplementation with sericin during embryo culture improves the quality of the embryos cultured individually but not the viability of the frozen‐thawed embryos after transfer to recipients. 相似文献
4.
Yotsushima K Sakaguchi M Shimizu M Okimura T Izaike Y 《The Journal of reproduction and development》2004,50(4):471-476
The objective of this study was to investigate the influence of fatty acid-free bovine serum albumin (BSA) or fetal calf serum (FCS) on the re-expansion of biopsied blastocysts and post-warm viability of subsequently vitrified embryos. Firstly, blastocysts produced in vitro were biopsied at Day 7 and cultured to allow repair in TCM199 with 0.3% BSA or 5% FCS for 24 h. The re-expansion rates and mean total numbers of cells of the re-expanded embryos after the repair culture with BSA were almost the same as that with FCS. Secondly, after biopsied embryos were similarly cultured for repair with BSA or FCS, re-expanded embryos were selected for vitrification. After warming and exposure to 0.5 M sucrose with 20% FCS in mPBS, the embryos were cultured in TCM199 with 5% FCS for 24 h. The re-expansion rate and mean total number of cells in re-expanded blastocysts in the BSA treatment group (97.4 +/- 2.9% and 106 +/- 42) was significantly higher than that in the FCS treatment group (51.6 +/- 9.1% and 61 +/- 38), respectively (P<0.05 and P<0.01). In conclusion, both FCS and BSA supplementation can be useful for repairing cultures of bovine biopsied blastocysts; but, compared with BSA supplementation, FCS supplementation during repair culture reduces the post-warm viability of biopsied and subsequently vitrified embryos. 相似文献
5.
Hiroshi Tajimi Tsugumi Yamazaki Syoko Oike Tatsuyuki Yoshida Konosuke Okada Masashige Kuwayama Hitoshi Ushijima 《Animal Science Journal》2018,89(8):1194-1200
This study was conducted to examine the utility of vitrification for bovine embryos with low‐quality grade, and simple cryoprotectants dilution method for practitioners. In Experiment 1, survival of frozen embryos was compared with that of vitrified embryos using minimum volume cooling (MVC). Then, vitrified embryos were used to confirm the optimum sucrose concentration in Experiment 2. The survival rates of embryos that had been vitrified following diluted cryoprotectants with the one‐step in‐straw method were compared with those of fresh control embryos in Experiment 3. Frozen‐thawed or vitrified‐warmed blastocysts were cultured with TCM‐199 supplemented with 100 μmol/L beta‐mercaptoethanol +5% fetal bovine serum at 38.5°C in an atmosphere of 5% CO2 in air, their survival after 24 hr were compared. The development to term of fair quality in vivo embryos after vitrification was examined in Experiment 4. Results show that survival rates of frozen‐thawed embryos were lower (p < .05) than that of vitrified‐warmed ones. When vitrified embryos were warmed in 0.3 mol/L sucrose in straws, their survival rate was 100%. The total cell numbers of vitrified‐warmed embryos were comparable to those of fresh control embryos. The six calves from 13 vitrified embryos were delivered in Experiment 4. These results indicate that MVC vitrification following one‐step cryoprotectants dilution is utilized to preserve low‐quality bovine embryos. 相似文献
6.
A method of reliably producing developmentally competent cat embryos in vitro is a prerequisite for study of the physiology of early development and application of assisted reproductive techniques. Oocytes were collected and then cultured in TCM-199 + 10% FBS for 4 h. The matured oocytes were activated with a 20 microsec electric pulse at 1.2 kV/mm. The activated oocytes were incubated in 2 mM of 6-dimethylaminopurine (6-DMAP) for 4 h and were then divided randomly among the treatment groups. In experiment 1, we compared the effects of three culture systems (TCM-199, CR1-aa and Tyrode's) on the in vitro development of parthenogenetically activated cat oocytes. In experiment 2, we investigated the effect of addition of Iloprost (a stable prostaglandin I(2) analogue) to Tyrode's medium on in vitro development of parthenogenetically activated oocytes. As a control, we recovered in vivo produced blastocysts and determined their average cell number. In experiment 1, the cleavage frequency of the oocytes cultured in TCM199, CR1-aa and Tyrode's media were similar (74, 72 and 83%, respectively). However, the incidence of in vitro development to the blastocyst stage was significantly higher in Tyrode's medium (20.4%) than in TCM-199 (2.4%) or CR1-aa (11.1%). Likewise, the average cell number of in vitro activated blastocysts was higher in Tyrode's than in CR1-aa or TCM-199 (106.5 +/- 45.2 vs. 68.3 +/- 25.4 and 35.0 +/- 7.7, respectively; P<0.05). In experiment 2, the percentage of parthenogenetically activated oocytes that underwent in vitro blastocyst development was significantly improved by addition of Iloprost to the culture medium (33.6 vs. 19.1%; P<0.05). The average cell number of in vivo blastocysts (909.0 +/- 226.4) was significantly higher than those of in vitro blastocysts cultured in Tyrode's medium supplemented with or without Iloprost (103.2 +/- 31.3 and 112.2 +/- 39.3, respectively; P<0.05). This result indicated that the current culture method for cat pathogenetically activated oocytes requires further improvement. 相似文献
7.
This study was conducted to determine the adequate medium for a serum‐free culture system of domestic cat embryos produced by in vitro maturation (IVM) and fertilization (IVF). Cumulusoocyte complexes recovered from cat ovaries were matured in vitro for 24 h, and then inseminated in vitro for 12 h. After insemination, the oocytes were cultured in five media [Ham's F10, Waymouth 752/1 (Waymouth), TCM199, modified Earle's balanced salt solution (MK‐1) and CR1aa], each of which contained 0.4% bovine serum albumin. There were no significant differences among the rates of fertilization of oocytes cultured in five media following IVF. The rate of oocytes/embryos developed to at least the morula stage was significantly lower (p < 0.05) in Waymouth than in MK‐1, TCM199 and CR1aa. Moreover, none of the embryos cultured in Ham's F10 and Waymouth developed to the blastocyst stage. There were no differences among the rates of development to the blastocyst stage of oocytes/embryos cultured in MK‐1, TCM199 and CR1aa. These results indicate that the type of serum‐free medium has a major impact on in vitro development of domestic cat embryos derived from IVM/IVF, and MK‐1, TCM199 and CR1aa media are suitable for in vitro culture of cat embryos in a serum‐free culture system. 相似文献
8.
Gustafsson H., U. Jaakma and M. Shamsuddin: Viability of fresh and frozen-thawed biopsied bovine embryos. Acta vet. scand. 1994,35,217-222.– Bovine embryos were biopsied using a simplified splitting technique and frozen-thawed according to a standard method with glycerol as cryoprotectant. The viability of fresh and frozen-thawed biopsied and intact embryos were evaluated after in vitro culture, by means of fluorescence test or following transfer to recipients. The survival rates after in vitro culture of fresh intact and biopsied embryos and of frozen-thawed intact and zona free embryos were not significantly different (70%, 60%, 68% and 52%, respectively), but significantly reduced for bipsied frozen-thawed embryos (16%) (p≤0.05). The pregnancy results after transfer of biopsied frozen-thawed embryos were also significantly lower (8%) compared to fresh biopsied embryos (39%) (p≤0.05). Both intact and biopsied embryos fluoresced after incubation with diacetylfluorescin but with higher intensity for the intact embryos. It is suggested that the reduced survivability for the frozen-thawed biopsied embryos might be caused by combined effects of the loss of the zona pellucida and the reduction of cells as a result of the simplified biopsy technique. It is concluded that improved biopsy and/or freezing techniques must be used if biopsied embryos have to be frozen. 相似文献
9.
Production of blastocysts after intergeneric nuclear transfer of goral (Naemorhedus goral) somatic cells into bovine oocytes 总被引：1，自引：0，他引：1
Oh BC Kim JT Shin NS Kwon SW Kang SK Lee BC Hwang WS 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(11):1167-1171
Interspecies cloning may be a useful method to help conserve endangered species and to study nuclear-cytoplasm interaction. The present study investigated in vitro development of goral (Naemorhedus goral) intergeneric nuclear transfer embryos produced by fusing goral fibroblasts with enucleated metaphase II (MII) bovine oocytes. After two to five passages, serum-starved or non-starved goral skin fibroblast cells were transferred into enucleated MII bovine oocytes. Couplets were electrically fused and chemically activated, and then cultured in either modified synthetic oviduct fluid (mSOF) or tissue culture medium-199 (TCM-199) supplemented with 10% FBS. Serum starvation of donor cells did not affect the fusion rate and or development to of cells to the two-cell stage, to more than 9-cells, or to morulae, regardless of culture medium. Three blastocysts from 202 fused embryos were obtained when embryos reconstructed with non- serum- starved donor cells were cultured in mSOF. However, no blastocysts were obtained when the embryos reconstructed with serum-starved donor cells were cultured in mSOF. The total cell number of goral intergeneric embryos averaged 130.3 (range 105-180). In conclusion, this study demonstrated that bovine oocytes can support blastocyst development after intergeneric SCNT with goral fibroblasts. 相似文献
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12.
This study was conducted to examine the potential for implantation and sustainable fetal development of mouse embryos cultured from the pronuclear to blastocyst stage. Pronuclear embryos from ICR mice (Harlan Sprague‐Dawley) were cultured in Sydney IVF sequential media (Cook) to the blastocyst stage in medium only or co‐cultured with autologous cumulus cells. We also experimented with co‐culture in 100 µL drops. Drop co‐culture produced blastocyst formation rates with a mean of 47.0%, which was significantly higher (P < 0.05) compared to embryos cultured in identical culture conditions except without cumulus cells at 27.3%. Blastocysts obtained in vitro in Cook medium only and co‐cultured in Cook medium with cumulus cells were transferred to pseudopregnant females of ICR strain. The day of blastocyst transfer into surrogate females was designated as post‐transfer of blastocyst day 1 (PT 1). The implantation and fetal development was compared to embryo transfer of in vivo derived blastocysts, which served as controls. There were no statistical differences for implantation and fetal development rates for blastocysts cultured in vitro in either Cook medium only or co‐culture in Cook medium with cumulus cells compared to in vivo‐derived blastocysts. The advantage of the co‐culture system is in generating more blastocysts available for transfer. 相似文献
13.
RH Alvarez M Meneghel AC Martinez RML Pires EA Schammass 《Reproduction in domestic animals》2008,43(3):257-260
The aim of this study was to evaluate if blastocysts arising from in vitro culture of Grade 3 bovine morulae produced in vivo can promote acceptable pregnancy rates when transferred into recipients. Embryos of different stages and qualities were recovered from superovulated Bos taurus and B. indicus donors. Grade 3 morulae were cultured in either Holding Plus® or TCM‐199 (supplemented with 10% bovine fetal serum) media for 24 h at 38.5°C. After this culture period, the resulting blastocysts were morphologically classified (Grades 1, 2 and 3) and transferred into recipients previously synchronized with the donors. Non‐cultured Grades 1 and 3 morulae were used as control. Pregnancy diagnosis was carried out 60 days after embryo transfer and the data were analysed by logistic regression, considering variables, such as embryo quality (Grade), donor breed, culture medium, donor‐recipient synchrony and seasonality. Embryo quality was the only variable, showing significant effect on the pregnancy rate. Pregnancy rates for non‐cultured Grade 1 and 3 morulae, and blastocysts arising from cultured Grade 3 morulae were 58.1% (n = 31), 17.1% (n = 35) and 51.1% (n = 47), respectively (p < 0.05). There were no statistical differences between non‐cultured Grade 1 morulae and cultured blastocysts. Pregnancy rates for Grades 1 (65.0%) and 2 (60.0%) were higher than Grade 3 (29.4%) cultured blastocysts (p < 0.05). It was concluded that short‐term in vitro culture is a very convenient method of identifying morphologically low quality morulae with higher chances of continuing development after the transfer into recipients. 相似文献
14.
K Korhonen K Kananen E Ketoja J Matomäki M Halmekytö J Peippo 《Reproduction in domestic animals》2010,45(1):42-49
Maturation of oocytes and the subsequent outcome of the in vitro production (IVP) are affected by the composition of in vitro maturation (IVM) medium. To determine the use of serum interfering with effects of single molecules, we aimed at developing simplified IVM medium. The experimental IVM media were: (1) M199-medium supplemented with hormones and serum (control), (2) as 1 but serum was substituted with fatty acid-free serum albumin (FAFBSA) and (3) M199-medium without hormonal and serum supplementation (M199). The quality of embryos was assessed on day 7 by morphology and cryotolerance, as well as by Terminal deoxynucleotidyl Transferase Biotin-dUTP Nick End Labeling (TUNEL) and differential staining. Results showed that the nuclear maturation was suppressed in M199 group alone. Embryo cleavage and development rates, and the proportion of quality 1 blastocysts were lower in the FAFBSA and M199 groups compared to the control. Differences in the cell allocation of fresh embryos were observed at the blastocyst stage, but not at the expanded blastocyst stage. The control group blastocysts had larger number of cells allocated to the inner cell mass (ICM), and the FAFBSA group blastocysts larger apoptotic cell proportion compared to the blastocysts derived from other groups. After cryopreservation, the reduction of ICM proportion and increase of apoptotic cell proportion of embryos were equal between the experimental groups. In conclusion, exclusion of serum from the IVM media reduces embryo development and may cause perturbations in blastocyst development. Differences in the cell allocation of blastocysts between IVM media may appear only when the developmental stages are taken into account. 相似文献
15.
Hiwasa M Kohno H Togari T Okabe K Fukui Y 《The Journal of reproduction and development》2009,55(1):50-54
The present study aimed to investigate the fertility of ewes artificially inseminated with three different methods using a synthetic semen extender, AndroMed. The three methods of artificial insemination (AI) were cervical AI with fresh-diluted or frozen-diluted semen at observed estrus, and an intrauterine AI with frozen-thawed semen. A total of 80 ewes were treated with a controlled internal drug release (CIDR) containing 0.3 g progesterone per device for 12 days. In Experiment 1 (26 Suffolk ewes), superovulation was induced with 20 mg follicle-stimulating hormone and 250 IU equine chorionic gonadotropin (eCG) two days and one day before CIDR removal, respectively, during the non-breeding season. In Experiment 2 (54 Suffolk and Suffolk crossbred ewes), an intramuscular injection of 500 IU eCG was administered one day before CIDR removal to synchronize estrus and ovulation during the breeding season. In Experiment 1, fresh-diluted or frozen-thawed semen was deposited into the cervical orifice after estrus detection, and an intrauterine AI with frozen-thawed semen was performed by laparoscopy at a fixed-time basis without estrus detection. Embryos were recovered by uterine flushing 6 days after AI, and the rates of recovered, fertilized (cleaved) ova and embryos at the morula or blastocyst stage were compared among the three AI methods. In Experiment 2, the pregnancy rates after the three AI methods were compared. In Experiment 1, the rates of recovered ova were not significantly different among the three AI methods (52.5-56.7%). The rate of fertilized ova (81.0%) by laparoscopic AI with frozen-thawed semen was significantly higher compared with cervical AI of fresh-diluted (25.5%) or frozen-thawed (3.5%) semen, but the rate of embryos at the morula or blastocyst stage (17.6%) was significantly lower than that of the cervical AI with fresh-diluted semen (69.2%). The rates of ewes yielding fertilized ova were not significantly different among the three groups (44.4, 11.1 and 62.5% for cervical AI with fresh-diluted and frozen-thawed semen and intrauterine AI with frozen-thawed semen). In Experiment 2, the pregnancy rate of ewes intrauterinally inseminated with frozen-thawed semen (72.2%) was significantly higher than those of ewes inseminated cervically with fresh-diluted (5.5%) or frozen-thawed (0.0%) semen. The present results showed that acceptable fertilization and pregnancy rates could be obtained by an intrauterine AI with frozen-thawed semen using a synthetic semen extender (AndroMed), but not sufficient by the cervical AI with either fresh or frozen semen. 相似文献
16.
Rat 1-cell embryos, recovered from naturally mated females, were cultured in a chemically defined medium (mR1ECM) or in mR1ECM supplemented with BSA (4 mg/ml; mR1ECM-BSA) or fetal bovine serum (FBS; 10%, v:v; mR1ECM-FBS) instead of polyvinylalcohol. There was no difference in percentages of embryos that developed to the 2-cell to blastocyst stages between mR1ECM and mR1ECM-BSA, but in mR1ECM-FBS, no development beyond the 2-cell stage was observed. When embryos were transferred to mR1ECM-FBS from mR1ECM after 24 to 64 h of culture, development of embryos to and beyond the 4-cell stage was inhibited. However, when transferred after 80 h of culture, more embryos developed to blastocysts and hatching or hatched blastocysts than in embryos cultured in mR1ECM. When 8-cell embryos and early morulae obtained after 72 and 80 h of culture in mR1ECM, respectively, were cultured in mR1ECM-FBS, a higher proportion of early morulae developed to the blastocyst stage than did 8-cell embryos. When morulae obtained after culture in mR1ECM or mR1ECM-BSA were transferred to recipient females, there was no difference in proportions of fetuses obtained. However, a higher proportion of blastocysts cultured in mR1ECM-FBS developed to fetuses compared with those obtained in mR1ECM. These results indicate that BSA has neither deleterious nor beneficial effects on development of rat 1-cell embryos. In contrast, FBS has deleterious effects on early cleavage of embryos but it promotes more rapid development of morulae to blastocysts, resulting in better quality blastocysts. 相似文献
17.
影响受体牛冷冻移植胚胎效果的主要因素 总被引：3，自引：0，他引：3
试验研究影响受体牛移植冷冻胚胎效果的主要因素,目的是解决胚胎移植产业化中容易出现的技术问题,以提高牛胚胎移植妊娠率。在季节、饲养管理、同期发情处理和胚胎移植技术以及环境条件等基本相同的情况下,结果表明:西门塔尔杂交牛的移植利用率和移植妊娠率高于黄牛杂交牛和黑白花奶牛,但各组间无显著性差异(P>0.05);2～6周岁的受体牛移植利用率和移植妊娠率高于7周岁以上和2周岁以下的受体牛,但各组间无显著性差异(P>0.05);经产1～3胎受体牛移植利用率显著高于4胎以上的受体牛(P<0.05),而移植妊娠率则无显著性差异(P>0.05);体况上等与中等的受体牛移植利用率和移植妊娠率无显著性差异(P>0.05);同期发情处理时卵巢处于黄体期的移植利用率显著高于卵泡期,差异极显著(P<0.01);左侧卵巢有黄体的子宫角胚胎移植妊娠率显著高于右侧(P<0.05);胚龄对胚胎移植妊娠率高低依次为早期囊胚、桑椹胚和囊胚,但无显著性差异(P>0.05)。 相似文献
18.
Development of frozen-thawed demi-embryos and production of identical twin calves of different ages.
N Seike M Sakai H Kanagawa 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1991,53(1):37-42
The percentages of morphologically transferable embryos obtained from frozen-thawed demi-embryos which were embedded with or without agar, and from those with or without zonae pellucidae were 26.3% (5/19), 36.4% (8/22), 39.5% (15/38) and 40.0% (22/55), respectively. No significant differences were observed between these groups. Development to calves of frozen-thawed demi-embryos with or without zonae pellucidae was 25.0% (3/12) and 26.7% (4/15), respectively. There was also no significant difference between them. On the trial for production of identical twin calves of different ages, the pregnancy rates of fresh and frozen demi-embryos after transfer were 69.2% (9/13) and 11.1% (1/9), respectively. Out of 13 fresh demi-embryos and 9 frozen demi-embryos transferred, only one pair of identical twin male calves of different ages were produced. This frozen-thawed demi-embryo was stored for 43 days in liquid nitrogen before thawing and transfer. These twin calves were confirmed to be identical by blood typing. Although these calves had different birth dates, their growth rates indicated similar developmental patterns. We suggest that it is possible to produce identical twin calves of different ages. This possibility would be useful for predicting the sex, milk producing ability and progeny test of a pair of demi-embryos before a decision to transfer the other half of a pair is made. 相似文献
19.
In vitro development of equine oocytes from preserved ovaries after intracytoplasmic sperm injection
Matsukawa K Akagi S Adachi N Sato F Hasegawa T Takahashi S 《The Journal of reproduction and development》2007,53(4):877-885
In this study, we evaluated the meiotic competence of equine oocytes from ovaries preserved for one day. We also investigated fertilization, cleavage rate, developmental competence and freezability of equine embryos after intracytoplasmic sperm injection (ICSI). After collection from ovaries, the oocytes were classified into two groups comprised of those having compact cumulus layers (Cp) or those having expanded cumulus layers (Ex). Oocytes with a first polar body were subjected to fertilization by ICSI using frozen-thawed stallion spermatozoa and were then cultured in CR1aa medium. The rates of metaphase II-stage oocytes, normal fertilization and cleavage were not significantly different between the two oocyte categories (38.5, 70.0 and 48.7% for CP and 43.5, 60.0 and 58.8% for Ex, respectively). However, the blastocyst development rate of Ex was significantly (P<0.05) higher than that of Cp (25.5 vs. 7.7%). Three Cp-derived and 12 Ex-derived early blastocysts were cryopreserved using the slow cooling protocol, and all of them developed to hatching blastocysts after thawing. These results suggest that equine oocytes fertilized by ICSI can develop to the preimplantation stage in culture conditions similar to those used in the bovine. Furthermore, the Ex oocytes had higher developmental competence than the Cp oocytes, and the in vitro-produced blastocysts had high viability after freezing and thawing. 相似文献