• Fisheries and Aquatic Sciences
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• 제4권1호
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• pp.39-46
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• 2001

To examine the effect of copy number-dependent transgenic genotype on the expression of foreign gene, stable hemizygous and homozygous transgenic breeding line was established using artificial parthenogenesis. For this purpose, induced diploid gynogenetic transgenesis was optimized in mud loach (Misgurnus mizolepis) using UV-irradiated cyprinid loach (M. anguillicaudatus) sperm and thermal shocks. Optimum UV range for inactivation of cyprinid loach sperm was between 3,150 to $4,050\;ergs/mm^2$ The UV-irradiated sperm were inseminated into eggs from recessive color strain (yellow) or heterozygous transgenic mud loach containing CAT gene. Cold shock at $2^{\circ}C$ for 60 min, 5 min post fertilization successfully restored the diploidy of eggs inseminated with UV-irradiated sperm. Restoration to diploidy was confirmed by flow cytometry and gynogenetic status was verified by examining maternal exclusive inheritance of multi-locus DNA fingerprints, body color and transgenic marker. Putative isogenic transgenic fish clearly showed homozygous status at trans gene locus based on Southern blot hybridization and progeny testing. Further, such homozygous gynogenetic diploids revealed the increased levels of transgene expression, when compared to those of heterozygous (hemizygous) transgenic fish.

• 한국양식학회지
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• 제12권3호
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• pp.167-173
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• 1999

Blocking the 1st mitotic cleavage was performed in mud loach (Misgurmus mizolepis) using UV-irradiated cyprinid loach (M. anguillicaudatus) sperm and ternal shocks Optimum UV range for inactivation of cyprinid loach sperm and thermal shocks. Optimum UV range for inactivation of cyprinid loach sperm was between 3,150 to 4,050 ergs/m$m^2$. Heat shock treatment ($41^{\circ}C$ for 3mins) with various treatment initiation times ranged from 22 to 50 min post insemination resulted wide range of success for induced gynogenesis. Best result was obtained when haploid egges were shocked at 28 min after insemination (corresponding to metaphase division of the 1st cleavage); 26% of total eggs inseminated were viable diploid gynogens. The hatching success and early survival of the both meiotic and mitotic gynogenetic groups were significantly lower than those of control crosses (P<0.05). Maternal origin of induced gynogenetic mud loach was verified by multi-locus DNA fingerprinting.

• 한국가축번식학회지
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• 제18권3호
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• pp.183-189
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• 1994

We examined early development in loach(Misgurnus mizolepis) embryos with parthenogenetic agents well-known in mammals. Female loach was superovulated with an intraperitoneal injection of 15 IU human chorionic gonadotrophin (hCG) per gram body weight. After 13 h of hCG injection, the oocytes were obtained from the abdomen. The oocytes were activated with 10% ethanol in tap water or fish Ringer's solution for 5, 10 and 15 minutes(eTW5, 10, 15 and eFRS5, 10, 15), respectively. The activation rates were 29% and 10% in eFRS10 and eFRS15, 5% and 6% in eTW10 and eTW15 by judging the cleaved blastomeres. Whereas, no parthenogenetic embryo was produced by tap water or fish Ringer's solution alone. The activation rate with the fish Ringer's solution was higher than that of tap water. No embryonic development was observed by calcium ionophore, A23187, at concentrations of 10, 20, 40 and 100$\mu$M when treated for 1, 2.5 and 5 minutes, respectively. The activation agents did not cause early development as in mammalian eggs. Therefore, the results suggest that fresh water fish may have a different egg activation pathway from that of mammals.

• 한국가축번식학회지
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• 제16권2호
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• pp.157-164
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• 1992

This stduy was carried out to obtain basic information available on ovulation, spawning, fertilization rate, hatching rate, and deformity rate after hCG injection in cyprinid loach, Misgurnus mizolepis. The results obtained in these experiments were as follows: 1. Ovulation and spawning occurred simultaneously and spawing was completed within 1 hour after ovulation. 2. More than 80% of fertilization rates appeared within 12 hours at 21$^{\circ}C$, 8 hours at $25^{\circ}C$, and 4 hours at 29$^{\circ}C$, respectively, following the onset of spawing. Afterwards, the fertilization rates of released eggs sharply decreased in three different water temperatures. 3. More than 70% of hatching rates appeared within 8 hours at 21$^{\circ}C$, 6 hours at $25^{\circ}C$, and 2 hours at 29$^{\circ}C$, respectively, following the onset of spawing. Afterwards, hatching rates of spawned eggs abruptly decreased in three different water temperatures. 4. The deformity rates of hatched larvae were high at $25^{\circ}C$, 8 hours following the onset of spawing. 5. Based on the developmental ability of oocytes, the optimum time of fertilization was 4 hours (stage 5) following the onset of spawing.

• 한국어류학회지
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• 제24권2호
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• pp.94-100
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• 2012

우리나라 고유종인 기름종개의 난발생 및 초기생활사를 연구하기 위해 2007년 6월에 전라북도 남원시 운봉읍의 낙동강에서 성숙한 개체를 채집하였다. 채집된 개체는 LHRH-1을 주사하여 건식법으로 인공수정시켰다. 성숙란은 분리침성란으로 밝은 회색이었으며, 난경은 $1.29{\pm}0.07mm$였다. 수정난은 수온 $23{\sim}25^{\circ}C$에서 수정 후 45~52시간 사이에 부화하였으며 크기는 전장 $4.5{\pm}0.24mm$였다. 부화 후 5일 후에 난황이 모두 흡수 되어 후기자어로 이행하고 전장 $6.6{\pm}0.13mm$로 성장하였으며, 부화 후 25일에는 지느러미 기조가 모두 정수로 되어 치어기로 이행하였고 전장 $9.0{\pm}0.49mm$로 성장하였다. 부화 후 100일 후에 반문모양과 외부형태가 성어와 유사하였고 전장 $27.3{\pm}2.82mm$로 성장하였다.

• 한국어류학회지
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• 제11권2호
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• pp.126-133
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• 1999

무지개송어 (Oncorhynchus mykiss), 메기 (Silurus asotus) 그리고 미꾸리 (Misgurnus anguillicaudatus)의 성숙 난자의 방사대 (zona radiata) 및 난문의 미세구조적 특징을 광학, 주사 및 투과 전자현미경을 이용하여 조사하였다. 무지개송어와 메기의 난에 있는 난문은 깔대기 형태의 전정과 방사대를 통과하는 끝이 작아지는 통로로 구성되어 있었다. 무지개송어와 메기의 난문은 편평한 구멍과 긴 통로로 구성된 구조를 나타내었다. 메기 난문의 구조는 무지개송어 난문의 구조와 일치되었다. 무지개송어의 난문을 구성하는 내부 벽은 시계방향(우선형)의 구조를 나타내었다. 미꾸리의 난문은 짧은 통로를 지닌 얕은 구멍을 가진 형태를 나타내었고, 시계방향의 반대방향으로 난문의 벽은 방향성율 나타내었다. 미꾸리의 이러한 나선형의 방향은 무지개송어의 방향과 일치하지 않는 것으로 나타내었다. 개구부 바로 주변부에 있는 표면은 실험에 이용된 3가지 어류에서 모두 여러 가지 크기의 작은 구멍이 존재하였다. 상호 연결부위 (ridge)가 모든 어류의 미수정된 난자에서 관찰되었다. 본 논문에서는 난성숙시 난막과 난문의 형태를 알아보기 위해서 3가지 양식어종 난자의 표면형태와 난문의 미세구조를 상호 비교하였다.

• 한국어류학회지
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• 제28권3호
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• pp.156-163
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• 2016

한국 고유종 남방종개 Iksookimia hugowolfeldi의 난발생 및 초기생활사를 밝히기 위하여 조사를 실시하였다. 성숙한 개체 복강에 Ovaprim (0.5 mL/kg)을 주사하여 12시간 경과 후 복부 압박법으로 채란하여 건식법으로 인공수정 시켰다. 산란된 난은 평균 $1,933{\pm}530$개로, 약한 점착성을 띤 밝은 노란색의 분리침성난이었으며, 난경은 $1.35{\pm}0.03mm$였다. 수온 $25^{\circ}C$에서 수정 후 56시간(50%)에 부화하였으며, 크기는 전장 $5.6{\pm}0.18mm$였다. 부화 후 5일에는 전장 $7.8{\pm}0.31mm$로 난황을 모두 흡수하여 후기자어기로 넘어갔으며, 부화 후 15일에는 전장 $13.2{\pm}0.87mm$로 지느러미 기조가 모두 정수가 되어 치어기로 이행하였다. 부화 후 100일에는 전장 $49.2{\pm}4.29mm$로 성장하고 외부형태 및 체측반문이 성어와 비교적 유사하였다.

• 한국어류학회지
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• 제31권1호
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• pp.30-38
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• 2019

한국고유종 점줄종개 Cobitis nalbanti의 난발생 및 초기생활사를 조사하였다. 성어는 2011년 6월 영산강 상류인 전남 장성군 북하면 성암리에서 족대를 이용하여 채집하였다. 채집된 성숙한 친어는 복강에 Ovaprim을 주사하고, 12시간 경과 후 복부압박법으로 채란하고 건식법으로 인공수정시켰다. 산란된 성숙란은 약한 점착성을 띤 밝은 황색의 분리침성난으로 난경은 $0.99{\pm}0.03mm$이고 산란수는 $1,527{\pm}410$개였다. 수온 $25^{\circ}C$에서 수정 후 52시간 후에 50%가 부화하였으며, 크기는 전장 $4.2{\pm}0.22mm$였다. 부화 5일 후에 전장 $6.0{\pm}0.34mm$로 난황이 모두 흡수되어 후기자어로 이행하였으며, 15일 후에는 전장 $10.8{\pm}0.45mm$로 지느러미 기조가 모두 정수로 되어 치어기로 이행하였다. 부화 후 100일 후에는 전장 $41.1{\pm}2.95mm$로 4개의 점줄로 이루어진 Gambetta's zone이 뚜렷하고 외형은 성어와 비교적 유사하였다.

• 한국가축번식학회지
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• 제11권3호
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• pp.170-180
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• 1987

This study was undertaken to determine the effects of HCG and trout pitutary on sexual maturation and ovulation in the Korean loach, Misgurnus anguillicaudatus. Sexual maturation was observed in the fish treated with 250＋125 IU HCG within 2-4 days following injections. Total ovary weight and GSI were significantly greater in the hormone-treated fish than in the control fish. Furthermore, in the hormone-treated fish body weight increased by about 4-9 percent in 2 days. The water content of the ovulated eggs of the fish treated with 250＋125 IU HCG was also greater than that in the control. Changes in both macroscopic & microscopic appearnce of Korean loach ovaries are describled, as well as changes in the gonadosomatic index. Oocytes pass through seven cytologically changes in the relative stages. By examining these stages, it was found that oogenesis occures in two broad phases. The previtellogenic phasebegins as a new oogonia continues to arise following spawning. These rapidly develop into early perinucleolus oocytes, which in turn develop into resting stage oocytes. Most oocytes remain in this stage when they develop into late perinucleolus oocytes. The vitellogenic phase begins as these late perinucleolus oocytes become transformed into early maturing oocytes through the accumulation of yolk. The cytoplasm completely fills with yolk as oocytes reach the late maturing stage. Shortly before spawning the final hyaline stage of developing is reached. Changes in the microscopic appearances of the ovaries were well correlated with changes in both gonadosomatic index and macroscopic appearance.

• 한국양식학회지
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• 제13권4호
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• pp.359-362
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• 2000

Mitotic gynogenesis was induced in the far eastern catfish, Silurus asotus using UV-irradiated heterospecific sperm and cold shock treatment. Eggs were activated with the sperm of mud loach, Misgurnus mizolepis which has been irradiated with UV at dose of 9,000 ergs/$mm^2$. To determine the optimum duration required to prevent the first cleavage, a cold shock at 4$^{\circ}C$ with duration of 20, 30 or 40 min was applied to the eggs 50 min after activation. To induce diploidization of mitogenesis, the most effective protocol was to apply cold shock to 50-min old (after activation) eggs at 4$^{\Circ}C$ for 30min.