• 한국양식학회지
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• 제4권1호
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• pp.31-66
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• 1991

담수산 징거미새우 Macrobrachium nipponense (De Hann)는 우리나라 남부의 하구 기수 구역에 서식하는 흔한 종으로 체장 약 7 cm 정도이며 우리나라 Macrobrachium 속의 새우 중에서는 가장 큰 종이다. 최근 자연 수역의 오염으로 자연에서의 이 종의 수가 급격히 감소되고 있어서 이에 대한 대책이 시급한 실정이다. 따라서 본 실험에서는 이 종의 인공종묘생산을 위한 기초로서의 생식생태 즉 교미전탈피 횟수, 교미전탈피의 형태학적 특징, 탈피기간중의 일일 먹이량, 교미 행동, 정자와 정포의 구조, 정소내의 수정관의 형태, 산란 기작, 적정인공수정 시간, 교미로 부터 산란에 소요되는 시간 및 과정, 수온과 염분농도에 따른 난발생 및 부화에 미치는 영향, 난부화과정을 조사하였고 그 결과는 다음과 같다. 1. 수온 $28^{\circ}C$ 감소량 $3.26{\~}4.35\%_{\circ}$ 에서 암컷은 $17{\~}18$일 주기로 성장 탈피를 하였고, $13{\~}14$일 간격으로 $4{\~}5$회의 교미전탈피를 하였다. 인공수정에 적절한 시간은 교미전탈피 후 14시간 이내였고 최적시간은 탈피후 8시간 이내였다. 교미시에 수컷은 한천질의 정포를 암컷의 복구에 넣었고 산란은 교미후 $6{\~}17$시간 후에 관찰되었으며 산란시에 체외수정이 된다고 사료된다. 수정난은 암컷의 유영지 사이에 안들어 진 포난실에 부착되며 그 수는 암컷 체장이 6.5 cm인 경우 약 $5000{\~}6000$입 정도이다. 2. 산란 직후의 알은 타원형이며 평균 크기는 $0.58{\times}0.48$ mm였고 난발생이 진행되면서 크기가 증가되어 마지막에는 $0.85{\times}0.48$ mm로 되었다 알의 장축(Y)와 소요일수(X)와의 상관관계는 Y=5.60194+0.007358X로 나타낼 수 있었다. 난의 발생은 표할이었으며 분할구는 4 세포기에 나타났다. 난발생은 수온 $22{\~}30^{\circ}C$에서 정상적이며 최적수온은 $26{\~}28^{\circ}C$로 나타났고, 염분도는 염소양 $0{\~}6.64\%_{\circ}$ 에서 정상적으로 발생하였으며 최적염분 농도는 $2.21{\%_{\circ}}$이었다. 난부화일수(Y)와 수온(X)와의 상관관계는 Y=50.803-1.355X로 나타났고 수온 $28{\~}28.6^{\circ}C$에서 산란에서 부화까지는 $12{\~}13$일이 소요되었다. 3. 교미전탈피는 성장 탈피와 형태적으로 큰 차이가 났으며 교미전탈피에서만 번식강모와 번식 섬모가 흉복갑부, 복부측판 및 $1{\~}4$번 유영지 기부에 나타났다.

• Clinical and Experimental Reproductive Medicine
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• 제25권2호
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• pp.123-128
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• 1998

Implantation rates remain low following human in vitro fertilization (IVF). Suboptimal culture conditions may limit the ability of embryos to hatch as blastocysts, and artificial opening of the zona pellucida has been proposed as a means to promote subsequent hatching (assisted hatching). In this study, assisted hatching (AH) by zona drilling using acidic Tyrode's solution was performed in 320 patients, due to their age of more than 38 years (group A), the thick zona pellucida (group Z; $ZP\geq0.18{\mu}m$), and failures in implantation more than 3 times in previous IVF-ET trial (group P). This study was designed firstly, to study the effects of AH on the outcomes of IVF-ET according to the indications and secondly, to verify the appropriate application of AH. The results were as follows; 1. There was no difference in pregnancy rate between AH group (26.6%) and non-AH group (26.5%). 2. Assisted hatching (AH) showed significantly higher pregnancy rate of the patients with thick zona pellucid a than those of the patients with age factor and with the history of repeated implantation failure. But in the patients with age factor only, AH resulted in higher pregnancy rate. 3. Interestingly, the patients with complex factors including zona factor (Z: 33.9%; ZA: 30.4%; ZP: 31.6%; ZAP: 21.4%) showed higher pregnancy rates than other complex factors excluding zona factor (A: 24.4%, P: 0%; AP: 10.8%). From these results, AH is more helpful to the patients with thick zona pellucida rather than patients with older age and/or previous repeated implantation failure.

• 한국어류학회지
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• 제36권1호
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• pp.20-29
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• 2024

삼세기(Hemitripterus villosus)는 새로운 양식 어종으로 대두되고 있으나, 자원량이 감소하고 있으며, 양식 어종에서 지속적인 문제로 나타나는 골격 기형에 대해 삼세기의 정상적인 골격발달 기준을 제시하고자 한다. 이 연구에 사용된 시료는 어획된 어미로부터 채란된 수정란을 부화시킨 자치어를 포르말린액에 고정한 뒤 Kawamura and Hosoya (1991) 염색법에 따라 염색하여 골격발달을 관찰하였다. 부화 직후 평균전장 13.65±0.71 mm (n=5) 일 때 부설골과 주상악골, 전상악골, 치골이 골화되기 시작하였고, 부화 후 65일째 평균전장 21.24±0.50 mm (n=5) 일 때 사골과 안상골이 골화하면서 두부가 완성되었다. 견대부는 부화 7일째 평균전장 14.61±0.52 mm (n=5) 일 때 쇄골, 주새개골, 관절골이 골화하기 시작하였으며, 부화 44일째 평균전장 18.15±0.61 mm (n=5) 일 때, 4개의 사출골이 골화되어 견대부가 완성되었다. 부화 10일째 평균 전장 14.80±0.65 mm (n=5) 일 때 척추골의 골화가 시작되었으며, 부화 후 54일째 평균전장 18.67±0.54 mm (n=5) 일 때 척추골 추체 39개가 골화하여, 부화 60일째 평균전장 20.25±0.45 mm (n=5) 일 때 척추골의 골격이 완성되었다. 이 연구는 삼세기 자치어의 골격발달에 대한 것으로 삼세기의 자치어 골격 기형의 기준과 기초자료 연구에 사용될 것이다.

• International Journal of Industrial Entomology and Biomaterials
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• 제26권1호
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• pp.61-66
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• 2013

Baculum elongatum has several peculiarities such as parthenogenesis, unique external features, changing body color, and dropping oviposition, which makes it a potential economically useful insect. Oviposition was performed by females without fertilization by the sperm of males. The oviposition period was $42.2{\pm}22.7$ days and the number of eggs per female was $109.5{\pm}70.5$ eggs. The hatch rate was 73.3% at $25^{\circ}C$ and 66.7% after low temperature treatment ($8^{\circ}C$ for 60 days). In nature, B. elongatum overwinters as an egg, but it can be assumed from the results that cold temperatures were not required for hatching. The hatch rate was 98.2% in the treatment using floral foam, fermented sawdust, and leaves. The developmental period was $100.9{\pm}4.2$ days for eggs, $55.3{\pm}4.6$ days for nymphs, and $49.7{\pm}16.0$ days for adults. The length of the eggs was $0.33{\pm}0.0$ cm and the lengths of the nymphs were clearly distinguishable according to the instar stage. Clover(Trifolium repens) was an excellent diet as it was similar to the host plant and could be used as an alternative diet. The rate of reaching adulthood for the insects was 66.7% on an artificial diet containing 25% acacia leaves. For sustainable mass rearing of nymphs or adults of B. elongatum, a natural diet could be used such as acacia (Robinia pseudoacacia), white oak (Quercus aliena), chestnut (Castanea crenata var. dulcis), and bush clover (Lespedeza bicolor), or an alternative diet such as clover or artificial diet.

• Clinical and Experimental Reproductive Medicine
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• 제38권2호
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• pp.87-92
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• 2011

Objective: This study aimed to determine the safety and clinical effect of artificial shrinkage (AS) in terms of assisted hatching of fresh blastocysts. Also, we evaluated the correlation between patient age and the effect of AS on clinical outcome. Methods: Two AS methods, using a 29-gauge needle and laser pulse, were compared. Seventy-three blastocysts were shrunk using a 29-gauge needle and the same number of other blastocysts were shrunk by a laser pulse. We evaluated the shrunken blastocysts hourly and considered them viable if they re-expanded >70%. Blastocyst transfer cycles (n=134) were divided into two groups: a control group consisted of the cycles whose intact embryos were transferred (n=100), while the AS group consisted of the cycles whose embryos were replaced following AS (n=34). The implantation and pregnancy rates of the control group and AS group were compared ($p$ <0.05). Results: The re-expansion rates of the 29-gauge needle and laser pulse AS groups were similar (56 [76.7%] vs. 62 [84.9%], respectively). All of the remaining shrunken blastocysts were re-expanded within 2 hours. There was no degeneration of shrunken blastocysts. The total and clinical pregnancy rate of the AS group (23 [67.6%]; 20 [58.8%], respectively) was significantly higher than that of the control group (47 [47.0%]; 39 [39.0%], respectively). In the older patient group, there was no difference in the clinical outcomes between the AS and control groups. Conclusion: These results suggest that AS of blastocoele cavity, followed by the transfer, would be a useful approach to improve the clinical outcome in cycles in which fresh blastocyst stage embryos are transferred.

• 한국발생생물학회지:발생과생식
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• 제20권1호
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• pp.31-40
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• 2016

This study was conducted in order to examine the egg development in red spotted grouper, Epinephelus akaara and the morphological development of its larvae and juveniles, and to obtain data for taxonomic research. This study was conducted in June 2013, and 50 male and female fish were used for the study. One hundred ${\mu}g/kg$ of LHRHa was injected into the body of the fish for inducing spawning, and the fish were kept in a small-sized fish holder ($2{\times}2{\times}2m$). Eggs were colorless transparent free pelagic eggs, 0.71-0.77 mm large (mean $0.74{\pm}0.02mm$, n=30), and had an oil globule. Hatching started within 27 h after fertilization. Pre-larvae that emerged just after hatching were 2.02-2.17 mm in total length (mean $2.10{\pm}0.11mm$), their mouth and anus were not opened yet, and the whole body was covered with a membrane fin. Post-larvae that emerged 15 days post hatching were 3.88-4.07 mm in total length (mean $3.98{\pm}0.13mm$), and had a ventral fin with two rays and a caudal fin with eight rays. Juveniles that were formed at 55 d post hatching, were 31.9-35.2 mm in total length (mean $33.6{\pm}2.33mm$), with red color deposited over the entire body, and black chromophores deposited in a spotted pattern. The number of fin rays, body color, and shape were the same as that in the adult fish.

• 한국발생생물학회지:발생과생식
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• 제18권1호
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• pp.13-23
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• 2014

This study is conducted to monitor the morphological developmental features of the egg development, larvae and juvenile of Epinephelus septemfasciatus, the fertilized eggs were gotton using artificial insemination. Matured parents are collected from marine caged fish farms in Geomun-ri, Samsan-myeon, Yeosu-si, Jeollanamdo Korea in June 2012. The fertilized eggs were pelagic eggs containing one oil globule, and measured 0.81~0.89 mm ($0.85{\pm}0.04mm$, n=50) in diameter. In regard to rearing environment, the water temperature is $21.0{\sim}23.0^{\circ}C$ and the salinity is 32.0~33.2‰. Hatching was observed from 48 hours after fertilization, the mouth and anus of prelarvae was not opened but had egg yolk at newly hatched. 4 days after hatching, the mouth and anus of postlarvae was opened and began to eat Rotifer and was measured 2.40~2.49 mm ($2.45{\pm}0.03mm$ n=10) in total length. 12 days after hatching, postlarvae was measured 3.77~4.67 mm ($4.27{\pm}0.33mm$) in total length, its the second pole tide of dorsal fin and the first pole tide of pelvic fin was extended longitudinally. 71 days after hatching, juvenile was measured 40.5~45.4 mm ($42.6{\pm}2.04mm$) in total length. Seven bands were observed in body, and pole tides of dorsal and pelvic fins were shortened.

• 한국발생생물학회지:발생과생식
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• 제17권4호
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• pp.345-351
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• 2013

This study examines the effects on fertilization rate (FR), hatching rate (HR), and normal individual rate after artificial fertilization using frozen thawed sperm according to the cryoprotectant (DMSO) concentration and the period of cryopreserved sperm of longtooth grouper, Epinephelus bruneus. Performing artificial fertilization using frozen-thawed sperm, after freezing the sperm at different DMSO concentration of 5.0%, 7.5%, 10.0% respectively, FR were (DMSO 5.0%: $99.5{\pm}0.8%$, DMSO 7.5%: $99.5{\pm}0.7%$, and DMSO 10.0%: $99.6{\pm}0.6%$). The results are not significantly different from the control fresh sperm (100%). HR also (DMSO 5.0%: $96.2{\pm}2.3%$, DMSO 7.5%: $95.3{\pm}3.6%$, 10.0%: $96.6{\pm}1.8%$) were not significantly different in each group. The normal individual rate after hatching using with control fresh sperm ($98.4%{\pm}0.5$) and DMSO concentration level of 5.0% ($97.8{\pm}0.1%$) were not significantly different. However, with 7.5% ($97.2{\pm}0.6%$) and 10.0% DMSO concentrations ($95.9{\pm}0.2%$) are lower than the normal individual rate after hatching observed in the control and 5.0% DMSO. Performing artificial fertilization using frozen-thawed sperm at different frozen period (2 days, 2 years, and 3 years), 10% DMSO FR and HR of 3 years (FR; $66.8{\pm}1.8%$, HR: $82.0{\pm}12.9%$) and 2 years (FR; $78.5{\pm}14.8%$, HR: $79.3{\pm}0.6%$) cryopreserved sperm were lower than control (FR; 100%, HR: $91.1{\pm}3.6%$) and 2 days cryopreserved sperm (FR; $99.6{\pm}0.6%$, HR: $96.6{\pm}1.8%$). These results suggest suitable DMSO concentration ranges of cryopreservation sperm for E. bruneus is 5 to 10% and with 2 to 3 years cryopreservation period, cryopreservation sperm can be useful for seed production.

• 한국수정란이식학회지
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• 제25권1호
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• pp.9-14
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• 2010

This study was conducted to find out the effects of artificial shrinkage (AS) on post-thaw development of bovine embryos. The blastocoelic cavity of blastocyst was punctured to remove its fluid contents and then incubated in the holding medium (HM) for 10 min. The punctured and non-punctured (control) blastocysts were equilibrated in vitrification solution 1 (VS1; TCM-199+20% FBS+10% EG) for 5 min and vitrification solution 2 (VS2; TCM199+20% FBS+35% EG+5% PVP+0.5 M Sucrose) for 1 min and vitrified by direct dropping into the liquid nitrogen. Vitrified blastocysts (punctured and control) were thawed and cultured in vitro (12 hr) for studying survival and hatching rates. The levels of shrinkage were measured by the volume of the blastocyst during equilibration in VS1 (at 1, 3 and 5 min of equilibration) and VS2 (at 30 and 60 sec of equilibration) that was considering the volume of non-punctured blastocyst in HM as 100%. The levels of shrinkage were higher in punctured group (62.4, 64.6, 64.3% at 1, 3 and 5 min in VS1; 50.6 and 52.7% at 30 and 60 sec in VS2) than control group (84.8, 86.6, 86.4% at 1, 3 and 5 min in VS1; 72.1 and 68.8% at 30 and 60 sec in VS2), but within each group the levels of shrinkage were similar. The survival (90.9%) and hatching (50.0%) rates of vitrified blastocysts at 12 hr post-thaw were higher in punctured group than that in control group (76.9% and 0.0% respectively). We confirmed that vitrification solutions (VS1 and VS2) have no toxic effect on the survival of blastocysts because the survival rates of blastocysts exposed to VS1 and VS2 for 24 hr were similar between punctured and control groups (94.3 vs. 96.0%; p>0.05). In conclusion, the preliminary data show that AS of blastocyst may improve survival and hatching rate after thawing.

• 한국어류학회지
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• 제28권1호
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• pp.9-18
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• 2016

이 연구는 능성어 (Epinephelus septemfasciatus)의 소화관 발달과정을 형태학적과 조직학적인 방법으로 부화 후부터 60일 동안 관찰하였다. 먹이 급이는 부화 후 2일부터 20일 동안 Rotifer (Brachionus rotundiformis)와 클로렐라 (Chlorella ellipsoidea)를 급이 하였고, 20일부터 Rotifer와 brine shrimp (Artemia salina)를 급이 하였으며, 23일부터 Rotifer와 Artemia, 배합사료를 급이 하였다. 자치어 10마리를 임의로 선택하여 10% 중성포르말린에 고정한 후 형태학적 관찰과 파라핀포매법에 의한 조직학적인 관찰을 하였다. 능성어의 RLG는 평균 0.87으로 육식성어류의 특성을 보여주었다. 부화 직후의 자어는 입과 항문은 열려있지 않았고, 소화관은 난황을 따라 일직선상으로 관찰되었다. 부화 후 5일째 후기 자어는 입과 항문이 열리면서 첫 섭식 활동이 관찰되었고, 부화 후 8일째 변태가 시작되었다. 부화 후 11일째 후기 자어 식도는 네 개의 층이 구분 되었으며, 식도와 중장, 직장에서는 배상세포가 관찰되었다. 부화 후 19일째 후기 자어는 공식이 시작되었으며, 그로인해 개체의 성장차이가 관찰되었다. 위는 내부가 팽창되면서 분문위, 위체부 및 유문위의 구분이 가능해졌고, 유문수가 분화되었으며, 장 전체에서는 배상세포를 관찰할 수 있었다. 부화 후 28일째 위내부에 위선이 분화되었다. 부화 후 38일째 후기 자어는 위에서 위액이 분비되는 것을 확인할 수 있었고, 유문수에 점막주름이 확인되었다. 부화 후 38일째에서 치어기로 이행하는 시기 동안 위 내강은 넓어지고, 위선의 숫자와 장내점액세포, 점막주름은 지속적으로 증가하거나 길어졌으나 조직화학적인 변화는 관찰되지 않았다. 따라서 본 연구는 형태학적 및 조직학적 방법을 이용하여 능성어의 소화관 분화 및 발달에 관한 정보를 얻고자 하였으며, 초기 종묘생산과정에서 적절한 먹이투여시기를 확립함으로써 성장 및 생존율 향상에 기초자료를 제공하고자 하였다.