• 한국가축번식학회지
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• 제18권1호
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• pp.25-29
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• 1994

This study was carried out to investigate the in-vitro fertilization rate survival rate of rapidly frozen porcine immature embryos. The porcine embryos following dehydration by cryoprotectants containing sucrose were directly plunged into liquid nitrogen and thawed in 3$0^{\circ}C$ water bath. Survival rate was defined as development rate on vitro culture or FDA test. The results are summarized as follows : 1. The in vitro fertilization rate of all frozen immature oocytes(6.7~26.7%) was very low, 35.0% of unfrozen oocytes and the rate of immature oocytes was very higher than that of mature oocytes. 2. The survival rate of all frozen immature oocytes(10.3~25.0%, 13.3~30.0%) was very low, 45% of unfrozen oocytes and the rate of immature oocytes was slightly higher than that of mature oocytes.

• 한국수정란이식학회지
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• 제17권2호
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• pp.117-121
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• 2002

본 연구는 소형견의 불임 해결을 위해 미숙난자를 보존 후 이용할 수 있는지의 여부를 판명하기 위하여 미성숙 난포란을 시간별로 배양한 뒤 vitrification 동결 융해후 체외수정율과 생존율을 조사하였다. 1 미숙난포란을 회수 후 1, 6, 12, 24시간 성숙 배양 후vitrification동결 융해 후 체외수정 시켰을때 수정율은 각각 31.4％. 22.5％, 11.9％ 및 5.3％로서 대조군의 수정율 60.0％에 비해 낮은 성적이었고, 회수 후 시간이 경과되지 않은 난포란이 높은 체외수정율을 나타냈다. 2. 미숙난포란을 회수 후 1, 6, 12 및 24시간 배양시킨 난포란을 vitrification 동결 융해 후 체외 수정시킨 배의 생존율은 각각 55.0％, 40.0％, 28.6％ 및 17.1％로써 대조군의 76.7％에 비해 낮은 생존율을 나타냈다.

• 농업생명과학연구
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• 제46권2호
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• pp.63-73
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• 2012

본 연구에서는 소나무 용기묘와 노지묘를 대상으로 조림과정에서 5가지 시비 처리(무시비, 심층시비 20, 50, 100g 및 표층시비 20g)에 따른 생존율, 생장 특성 및 묘목품질지수를 조사 분석하였다. 조림지에 묘목 식재 시 시비처리에 따른 생존율은 처리구별 뚜렷한 차이가 없었으며, 심층시비 100 g 시비를 실시하여도 과량 시비에 의한 피해를 보이지 않았다. 소나무 용기묘와 노지묘의 연차별 근원경과 묘고 생장은 심층시비 100 g에서 가장 높았으며 또한, 물질생산량과 묘목품질지수에서도 생장 특성과 같은 경향이 나타났다. 모든 시비 처리구에서 전반적으로 용기묘가 노지묘보다 우수한 생장을 보였으며, 적정 시비 처리에 따른 효과 또한 용기묘가 노지묘보다 더 높은 것으로 조사되었다.

• 한국수정란이식학회지
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• 제11권2호
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• pp.125-135
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• 1996

The present study was carried out to investigate the effects of cryoprotectants, equilibration step, freezing rate, culture condition following in vitro fertilization, and age and development stage of embryo by freezing with conventional slow freezing and vitrification on survival of frozen-thawed Korean native cattle(KNC) blastocysts produced in vitro. The KNC blastocysts produced in vitro were equilibrated in 1.8M ethylene glycol or 1.4M glycerol and cooled from -6$^{\circ}C$ to -35$^{\circ}C$ at -0.3$^{\circ}C$ or -O.6$^{\circ}C$ /minute. When equilibrated in 1.8M ethylene glycol, survival rate of fiozen4hawed blastocysts was sarne in both -0. 3$^{\circ}C$ /min and -0.6$^{\circ}C$ /min cooling rate(71.4%). With the equilibration in 1.4M glycerol, survival rate was higher in -0.3$^{\circ}C$ /min(63.6%) than in -0.6$^{\circ}C$ /min cooling rate(53.8%). For vitrification of the KNC blastocysts produced in vitro, they were equilibrated in 2-step or 3-step exposure to vitrification solution(25% ethylene glycol + 25% glycerol). Survival rate was sirilar in both 2-step(45.0%) and 3-step exposure(47.4%). According to culture condition following in vitro fertilization, higher survival rate was obtained for blastocysts co-cultured with bovine oviductal epithelial cell(BOEC, 77.3%) than for those cultured with epidermal growth factor(EGF, 65.7%) or for those co-cultured with BOEG + EGF (54.8%). According to embryo age and development stage, higher survival rate was obtained for 7-day ernbryos(70.0%) than 8-day(56.8%) or 9-day(20.0%) for blastocyst stage and obtained for 8-day embryos(74.3%) than 7-day(62.5%) or 9-day(42.9%) for exponded blastocyst. In surnmary, higher survival rate of frozen4hawed KNC blastocysts produced in vitro were obtained by using ethylene glycol for cryoprotectant and -0.3$^{\circ}C$ /min for cooling rate. And higher survival rate were obtained with co-culture with BOEC for culture condition following in vitro fertilization and with 7-day blastocyst or 8-day expanded blasto cyst for embryo age and development stage.

• Clinical and Experimental Reproductive Medicine
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• 제19권2호
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• pp.163-168
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• 1992

This study was carried out to set up the ovum bank for ovum donation and to determine the best freezing method for human immature oocytes. Human immature follicular oocytes were cryopreserved by slow freezing and rapid thawing method. Immature follicular oocytes were treated by propanediol(PROH) solution by 2 and 4 step method in protocols A & B, respectively. In protocol C, immature oocytes were exposed to sucrose prior to treatment of PROH by 4 step method. We compared survival rate, maturation rate, and fertilization rate of immature oocytes among three protocols. Results were as follows. 1. Oocytes treated by the protocol C showed the highest survival rate( 70.3 %) and maturation rate(34.6%) after thawing. 2. Survival rate of oocytes treated by the protocol C was significantly higher than that of the protocol B after thawing(p<0.05). In conclusion, treatment of oocytes with sucrose prior to expose PROH was the best freezing method. Sucrose may have reduced the toxic effect of cryoprotectant to oocytes. We failed to induce fertilization of oocytes, which were treated by any protocols, by conventional insemination method, but obtained 28.8% fertilization rate by using partial zona dissection(PZD) method. This result suggests that micromanipulation(PZD) of the thawed oocytes before insemination will improve the fertilization rate.

• 한국수정란이식학회지
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• 제12권2호
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• pp.151-159
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• 1997

In vitro fertilization(IVF) derived morula and blastocyst embryos were bisected by a simple method and cultured in vitro without zona pellucida And also bisected embryos were frozen-thawed and cultured in vitro) to evaluate the survival rate. The results obtained were as follows : The average number of grade I or II immature follicular oocytes recovered by slicing method per ovary was 11.9 from 142 ovaries. Following in vitro fertilization, the rates of cleavage and in vitro development to morula and blatocyst were 61.7 and 32.2% respectively. The successful bisection rate of IVE embryos was 67.51%, and the embryos of blastocyst stage were bisected successfully at significantly(P

• 한국수정란이식학회지
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• 제10권2호
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• pp.115-120
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• 1995

This study was carried out to investigate On in vitro fertilization, survival rate and developmental rate of rapidly frozen bovine immature oocytes. Immature oocytes cultured for 1, 12, 24, 48 hours in 20% FCS + TCM-199 medium and thereafter rapidly freezing-thawed oocytes inseminated with capacitated sperm. The immature oocytes following dehydration by 1.5M DMSO + 2.0M glycerol + 0.25M sucrose + TCM 199 media + 20% FGS were directly plunged into liquid nitrogen and thawes in 3$0^{\circ}C$ water. Rapid freezing embryos co-cultured in 20% FCS + TCM-199 media containing hormones(21U/mL PMSG, 21U /mL hGG and 1 $\mu$g /mL 17$\beta$-estradiol) and cumulus cells(1 x 105-6 cells). Survival rate was defined as development rate on in vitro culture or FDA-test. The results are summarized as follows ; 1. The in vitro maturation and fertilization rate of immature bovine oocytes on in vitro maturation period(1, 12, 24, 48 hrs) before rapid freezing4hawed were 57.1%, 45.7%, 37.1%, 25.7% and 40.0%, 31.4%, 20.0%, 11.4%, respectively. 2. The survival rate of immature bovine oocytes on in vitro maturation period(1, 12, 24, 48 hrs) before rapid freezing-thawed were 33.3%, 26.7%, 20.0%, and 10.0%, respectively. The survival rate of rapid freezing4hawed immature oocytes was significantly lower than that of non-freezing oocytes. 3. The survival rate of rapid freezing4hawed excellent and good bovine embryos co-cultured in 20% FCS + TCM-199 media containing hormones(PMSG, hCG, 17$\beta$-estradiol) and cumulus cells 4 to 5 hrs and 20 to 24 hrs were 35.0%, 15.0% and 25.0%, 15.0% and 40.0%, 20.0% and 30.0%, 15.0%, respectively. The survival rate of embryos co-cultured in TCM-199 media containing hormones and cumulus cells was significantly higher than that of non co-culture.

• 한국기후변화학회지
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• 제6권3호
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• pp.249-256
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• 2015

This study was conducted to investigate the effects of different levels and types of nitrogen fertilizer on seedlings and soil chemical properties in a semi-arid area, Mongolia. 2-year-old Populus sibirica and 4-year-old Ulmus pumila seedlings were planted in May 2014. Six treatments with three levels of nitrogen (low-level: urea $5g\;tree^{-1}$; medium-level: urea $15g\;tree^{-1}$, ammonium sulfate $33g\;tree^{-1}$, urea $15g\;tree^{-1}$ with potassium phosphate $10g\;tree^{-1}$; high-level: urea $30g\;tree^{-1}$) were applied and for the medium-level of nitrogen, different types of fertilizer were treated. Survival rate, root collar diameter (RCD) growth rate, leaf nitrogen concentration of seedlings, and soil chemical properties were determined in August 2014. The seedling survival rate of both species decreased as the level of nitrogen increased. This result can be explained by water stress caused by nitrogen fertilization in arid regions. The RCD growth rate of P. sibirica was significantly decreased by the treatment of high-level of nitrogen due to excessive nitrogen fertilization, and was increased by the treatment of ammonium sulfate due to sulfur which might promote nitrogen uptake. The leaf nitrogen concentration of P. sibirica did not change by the treatment of low-level of nitrogen, and was increased by the treatment of medium-level of nitrogen. There were no significant differences in the RCD growth rate and the leaf nitrogen concentration of U. pumila among the six treatments. None of soil chemical properties was affected by nitrogen fertilization. Overall, the low-level of nitrogen showed no effect on seedlings and soil chemical properties, except on survival rate of U. pumila and the high-level of nitrogen was considered excessive fertilization. Continuous monitoring of medium-level nitrogen fertilization including the ammonium sulfate, which increased early growth of seedlings, would be needed to elucidate the effect of fertilization on seedling growth and soil properties in a semi-arid region.

• Ocean and Polar Research
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• 제37권1호
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• pp.37-47
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• 2015

The effects of low salinity (fertilization success and larval survival) on the limpet Cellana grata were studied at early stages of development using the marine bioassay technique. It was shown that, under normal conditions for development from fertilization to the post veliger stage, the salinity must be not less than 20.0~35.0 psu. However, the fertilization rate and larval survival of C. grata was obviously reduced at 5.0 psu and 10.0 psu, respectively. Mass mortality was estimated to occur at <20.0 psu (48-h $EC_{50}=19.54psu$) and the survival rate of normal veliger larvae decreased with experimental time during exposure. No observed effective concentration (NOEC) and lowest observed effect concentration (LOEC) of post veliger were estimated at 30.0 psu and 25.0 psu, respectively, during 48-h exposure. The tolerance limits of the test species to salinity revealed various concentration ranges of salinity, which may reflect the physiology and ecology of the initial development stages of C. grata. These results demonstrate that reduced salinity is detrimental to the reproductive success and larval survival of C. grata, and if salinity is lowered by natural or anthropogenic sources during spawning, this would lead to decreased reproductive success and larval settlement.

• 한국양식학회지
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• 제17권1호
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• pp.46-50
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• 2004

In the present study, attempts were made to cryopreserve sea urchin, Anthocidaris crassispina sperm in liquid nitrogen, to evaluate the effects of various cryoprotectants and freezing rates on motility, survival rate and fertilization rate of the post-thawing sperm, and the ultrastructural changes of sperm after cryopreservation were observed. The highest values of sperm motility (motility index: 3.3$\pm$0.37) and survival rate (72$\pm$3.5%) were obtained with 15% dimethyl sulfoxide (DMSO), and these values were significantly higher than those of sperm preserved with glycerol. Comparisons of motilities and survival rates between treatments of difference freezing rates showed that there was no difference between procedures (a) 5$0^{\circ}C$/min to -8$0^{\circ}C$ (motility index: 3.3$\pm$0.31 ; survival late 70$\pm$2.7%) and (b) 3$0^{\circ}C$/min to -8$0^{\circ}C$ (motility index: 3.1$\pm$0.29; survival rate 69$\pm$3.7%), while the results of (c) 1$0^{\circ}C$/min to -8$0^{\circ}C$ were significantly lower than the others (motility index: 2.2$\pm$0.33 ; survival rate 42$\pm$4.6%). There was no significant difference in fertilization rate between fresh sperm and sperm preserved with 15% DMSO as cryoprotectant and freezing rate (3$0^{\circ}C$/min to -8$0^{\circ}C$). Some ultrastructural changes of sperm, such as the detachment of plasma membrane, the destruction of mitochondria, and the flagellum rolling up head, were observed after cryopreservation. Morphological normality of the sperm in 15% DMSO frozen at the ratio of 5$0^{\circ}C$/min to -8$0^{\circ}C$ was better than the others.