• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 1999.02a
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• pp.43-46
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• 1999

The microstructure of Top Seed Milt-Processed $YBa_{2}$$Cu_{3}$$O_{7-\delta}$ single crystal was studied. It was presumed that the segregation of Y211 is due to the difference of growth rates between a, b axis and c axis in crystal direction. Corn kernel lide structure which was grown by the diffusion of Y211 was observed. At the near corner of the seed crystal, the diagonal line on Y123 cry crystal is formed by the corn kernel like structure.

• Development and Reproduction
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• v.19 no.4
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• pp.253-258
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• 2015

Spermiation was stimulated in the mature grass puffer, Takifugu niphobles, with an injection of human chorionic gonadotropin (HCG) or carp pituitary extract (CPE). Spermatocrit and sperm density were reduced, but milt production was increased in both the HCG and CPE treatment groups relative to those in the control group (P < 0.05). These results should be useful for increasing the fertilization efficiency in grass puffer breeding programs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.4
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• pp.474-480
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• 1996

Physicochemical changes of milt during the spermiation period were investigated in black seabream (Acanthopagrus schlegeli) reared in recirculating seawater system. The spermiation period for the milt collection in cultured brood stock was from 11 April to 4 June. During the spermiation period, average milt volume (ml/100 g body weight) was $0.70{\pm}0.33\;ml$ and maintained high level from 2 May to 4 June. The total number of stripping spermatozoa per 100 g body weight reached the maximum value $(3.32{\times}10^{10})$ in 9 May, then decreased rapidly thereafter. Spermatozoa concentration per ml reached the minimum value in 2 May. There was no change in spermatocrit for the spermiation period. Total protein, total lipid, glucose and Na concentration in spermatozoa and seminal fluid were lower than those in plasma. Total protein, total lipid and K concentration in spermatozoa were higher than those in seminal fluid. The glucose concentration in spermatozoa and seminal fluid in April and May were significantly higher than those in June.

• Development and Reproduction
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• v.11 no.3
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• pp.227-233
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• 2007

The milt properties of filefish(Thamnaconus modestus) included physical properties of sperm and biochemical properties of seminal plasma. The physical properties of milt were $0.3{\pm}0.1\;mL{\cdot}fish^{-1}$ in sperm volume, $2.6{\pm}0.1{\times}10^7\;spermatozoa{\cdotg}mL^{-1}$ in sperm concentration and $73.3{\pm}6.7$ in spermatocrit. The biochemical properties of seminal plasma contained $9.8{\pm}0.9\;mmol{\cdot}L^{-1}$ potassium, $164.0{\pm}4.0\;mmol{\cdot}L^{-1}$ sodium, $151.0{\pm}1.2\;mmol{\cdot}L^{-1}$ chloride, $14.9{\pm}0.6\;mg{\cdot}dL^{-1}$ calcium, $7.2{\pm}0.1\;mg{\cdot}dL^{-1}$ magnesium, $1.0\;mg{\cdot}dL^{-1}$ glucose, $0.1\;g{\cdot}dL^{-1}$ total protein and $1.0\;mg{\cdot}dL^{-1}$ total lipid. The osmolality and pH of seminal plasma were $322.8{\pm}2.8\;mOsmol{\cdot}kg^{-1}$ and $7.7{\pm}0.1$, respectively. The spermatozoon of filefish consisted of three parts: head without acrosome, mid-piece with five mitochondria and flagellum with "9+2" pattern. The head of spermatozoon in longitudinal section was horseshoe-shaped, and $1.3{\sim}1.6\;{\mu}m$ long and $1.0{\sim}1.3\;{\mu}m$ wide.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.52-52
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• 2003

For the evaluation of hormonal control of spermiation in fish, a method to quanify the spermiation response or mature Rhynchocypris oxycephalus (Sauvage and Dabry) to hormonal therapy is described. Spermatocrit was determined after 7 min centrifugation at 18,000 $\times$ｇ and sperm density was estimated by a standard hemocytormer method. Sperm density can be predicted from spermatocrit since their relationship is linear as described by the regression equation, Y=3.68X-27,18 ($R^2$=0.82, N=50), where Y is spermatocrit and X is sperm density. Milt production by mature R. oxycephalus was highest at 24 h after injection of 1,000 IU human chorionic gonadotropin (HCG) and 50 $\mu\textrm{g}$ luteinizing hormone-releasing hormone analogue (LHRHa) per kg body weight. Increased milt production coincided with low spermotocrit and sperm density levels. These results demonstrate that spermition in mature R. oxycephalus can be reliably evaluated by a spermatocrit method and that HCG and LHRHa are effecove in stimulating of spermiation in this species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.3
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• pp.296-301
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• 2017

We conducted a study to 1) determine the indicators of gonadal maturity in male and female Korean walleye pollock Theragra chalcogramma for the purposes of artificial insemination; 2) establish the RNA/DNA ratio of mature eggs in this species; and 3) monitor the effect of refrigerated storage on egg viability and the motility of sperm collected from dead adult males. During the spawning season, the color of female gonads changed from orange to transparent, and that of male gonads changed from pale orange to milky white. The DNA content and RNA/DNA ratio of mature eggs were maintained without significant changes for approximately 6 h when eggs were preserved at $4^{\circ}C$. Sperm could be obtained from both milt and undiluted semen. Sperm obtained from milt ceased moving on the second day after isolation, while over 60% of sperm obtained from semen showed movement until the 13th day. Seven attempts were made to artificially inseminate mature eggs, of which two resulted in successful fertilization. The successful inseminations produced 94,000 and 5,000 fertilized eggs, respectively. This study shows that artificial insemination of walleye pollock is a viable strategy when natural propagation is not possible.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.809-815
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• 1997

A series of experiments were conducted to study effects of osmolality and $Ca^{2+}$ on sperm motility in marbled sole, Limanda yokohamae. Spermatozoa were immotile when the milt was mixed with solutions (electrolyte or non-electrolyte) of lower osmolality than the average seminal plasma osmolality (351 mOsm/kg), but became motile after mixing milt with an hyperosmotic solution. However, with the osmolality above 1,639 mOsm/kg spermatozoa ceased their movement. When the milt was suspended in the $Ca^{2+}$ free artificial seawater (ASW) containing ethylenglycoltriamine (EGTA), the percentage of motile spermatozoa decreased in proportion to the increase of EGTA. Most spermatozoa were quiescent in a medium containing 3 mM EGTA. The motility of spermatozoa prevented by 3 mM EGTA was recovered by the subsequent addition of $Ca^{2+}$ over the concentration of 0.25 mM. Effects of calmodulin antagonist, trifluoperazin (TFP) on spermatozoa were examined to elucidate the possible functions of calmodulin in sperm motility. TFP immobilized spermatozoa 5n ASW at the concentration of 0.5 M. These findings suggest that calcium is an effective external factor in the initiation process of sperm motility.

• Korean Journal of Ichthyology
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• v.31 no.4
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• pp.195-200
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• 2019

An experiment was performed to obtain cryopreservation techniques of Pacific cod Gadus macrocephalus sperm. Milt were cryopreservation using five cryoprotectant demethyl sulfoxide (DMSO), ethylene glycol (EG), glycerol, methanol and propylene glycol (PG) with marine fish ringer's solution (MFRS) as diluent. Milt were cryopreserved each experimental methods like cryoprotectants (10% and 20%), equilibration time (3, 5 and 10 min) and freezing protocols (liquid nitrogen vapor above 3, 8 and 12 cm). Post-thaw sperm survival rate revealed the highest in 10% PG with optimum methods of equilibration time (3 min) and freezing protocol (liquid nitrogen vapor above 8 cm) about 21.3±1.8%. Hatching rate of fertilization eggs using fresh and cryopreserved sperm were no significantly different.

• Food Science of Animal Resources
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• v.22 no.2
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• pp.172-178
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• 2002

Vitamins are bio-active materials and essential elements in our body but some of them are very low in milt Various vitamin-fortified milks are developed by the help of milk processing technology. However, heat treatments can affect vitamins contents in milk. Total loss of vitamins during the UBT(ultra high temperature) treatment was investigated. UHT treatment caused 60∼70% loss for vitamin C, and 30∼40% loss for vit. D3 and vit. E which are well-known as heat stable materials. On the contrary, degradation of water-soluble vitamins is relatively very low in the capsule-coated state. The capsule could reduce the loss of vitamins by protecting vitamins from the degradation factors such as heat, oxygen, lights etc. The fortification method using capsule can be thought as a new way to reduce the loss of vitamins during milk processing. Further study about heat treatment time and temperature, and capsule coating and materials will be required to minimize the loss of vitamins in milt.

• Journal of Aquaculture
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• v.17 no.1
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• pp.8-11
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• 2004

Milt of the catfish was stripped into immobilizing solution containing 175 mM NaCl and 30 mM Tris at pH 7.8 and was successfully cryopreserved after a stepwise freezing procedure. After stepwise thawing, motility of spermatozoa was slightly lower than that of fresh sperm. Batches of 40-80 eggs were fertilized with cryopreserved spermatozoa, after thawing and activation in solution containing 50 mM NaCl, 20 mM Tris and HCl at pH 7.8; this resulted in 62.2% fertilization success, compared to 70.6 % with fresh sperm.