• Clinical and Experimental Reproductive Medicine
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• v.18 no.1
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• pp.23-34
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• 1991

In order to study the sperm-egg interaction during fertilization process in mouse, the effects of sperm concentration, the duration of capacitation and insemination, the stages of maturation and development of eggs, and sperm extracts and BSA on sperm binding to egg were examined. Sperm-egg binding was increased depending on sperm concentration within the range of $10^3-10^6$ sperm/ml. It showed the most numbers of sperm-egg binding at 60min from the beginning of preincubation(capacitation) and insemination, respectively. During sperm capacitation, sperm-egg binding inhibitor was released from sperm into the incubation medium. Sperm extracts containing trypsin-like enzyme which is secreted through the acrosome reaction increased the binding. BSA in the culture medium showed a positive effect on the binding. It is suggested that physicochemical alterations of zona pellucida in the process of maturation and fertilization of eggs leaded to inhibition of sperm-egg binding.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.6
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• pp.1402-1411
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• 2014

This study about morphological observation of pre- or post ovulated eggs obtained from artificially maturated female eels. Female eels were divided with two groups as wild eels from nature and feminized eels from farm. Artificial maturation had been conducted with the established methods in this laboratory, and then maturate eggs sampled at fixed 3 times and these were observed with stereomicroscope. Rate of increased body weight (RIW) were measured with 2 times. Egg diameters and development of oil droplets are determined for standardization of egg maturation degree, and the transparency of egg cytoplasm and the homogeneous degrees of egg size were referred to determine of egg quality. Rate of increased body weight (RIW) were good in range about 10 % at final salmon pituitary extracts (SPE) injection time and in range about 20 % at $17{\alpha}$, $20{\beta}$-dihydroxy-4-pregnen-3-one (DHP) injection time. Good matured egg for fertilization had $900-1000{\mu}m$ diameter, and they had about 50 oil droplets in size about $100{\mu}m$ diameter. There were not predominant differences at egg size and oil droplet development between wild female and feminized eels.

• Proceedings of the Zoological Society Korea Conference
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• 1996.10a
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• pp.135.2-135
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• 1996

No Abstract, See Full Text

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.11a
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• pp.102-102
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• 2002

• Fisheries and Aquatic Sciences
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• v.13 no.2
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• pp.140-149
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• 2010

We determined the seasonal gonad maturation in Strongylocentrotus nudus sea urchins inhabiting an artificially enhanced seaweed forest along the Samchuk Coast of Korea from April 2006 to March 2007. A total of 30 sea urchins per month were collected from the study area, and gonadosomatic index (GSI), gonad index (GI), egg diameter, and RNA/DNA variation were measured for each specimen. GSI values of female and male urchins achieved maximums of 17.6 and 17.0, respectively, in June. Based on histological studies, maximum GI values occurred in July (4.6 for females and 4.8 for males). A mean ovarian egg diameter of $73.7\;\pm\;14.2\;{\mu}m$ was measured in August; during the main spawning period in September, mean egg diameter reached a maximum of $74.2\;\pm\;17.8\;{\mu}m$. The RNA/DNA ratio and RNA content for both males and females showed a distinct peak during the ripe stage in July, but another peak occurred in the spring season from March to April, when urchins deposit protein into the nutritive phagocytes of immature gonads prior to gametogenesis. The reproductive cycle of S. nudus is divided into five stages: early active (December-May), late active (March-July), ripe (July-September), spent and degenerative (August-November), and inactive (October-February). Our continuous removal of sea urchins from the study area did not influence the reproductive cycle, as populations quickly recovered, and achieved normal gonad development cycle in the site.

• Korean Journal of Poultry Science
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• v.41 no.4
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• pp.287-296
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• 2014

Chicken eggs undergo various physiological changes during egg maturation. To study genes associated with the egg maturation in pre-ovulation (immature) and post-ovulation (mature), we compared gene expression patterns between in the immature egg and mature egg using RNA sequencing data. Mature and immature eggs were obtained from a Heuksaek Jaerae-jong of Korean native chicken. Total RNAs obtained from the eggs were sequenced by Illumina HiSeq 2000 platform, and the generated sequence reads were mapped to Galgal4 reference sequence assembly using Tuxedo Protocol. From the comparison of the RNA sequencing data, 315 genes were differentially expressed between mature and immature eggs, and 46 genes were only detected in immature egg. Further gene ontology (GO) analysis was performed for the differentially expressed genes using DAVID, showing that 29 and 28 GO terms were independently clustered from mature and immature, respectively. From those clustered GO terms, genes related to germ cell development, sex differentiation and defense response to bacterium were mainly expressed in the immature egg, while genes related to regulation of apoptosis, steroid metabolic process and lipid homeostasis were mainly detected in the mature egg. Our results could contribute to understand egg maturation before and after ovulation, and develop genetic markers for improving egg quality and productivity.

• The Korean Journal of Zoology
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• v.31 no.1
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• pp.21-28
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• 1988

The present study was carried out to examine the fertilizability of the mouse oocytes pre-ex-posed to dbcAMP which is a well-known inhibitor of the oocyte maturation. The oocytes once cultured in the dbcMP-containing medium for a certain length of, time were cultivated in the dbcMp-free medium to induced the maturation, then mixed with sperms, and observed following culture for 24 hours. The fertilization rate of cocytes was judged by the index of the number of 2-cell embryo developed 24hr following insemination. The fertilization rate of the oocyte previously incubated with dbcAMP (100 g/ml) for 2, 4, 8 16 hours was 32.3, 14.5, 4.7 and 8.8%, respectively, while that of the control was 53.3% indicating that the fertilizability was decreased as a function of time exposed to dbcAMP. The pretreatment of dbcMP, however, didn't affect the process of sperm penetration to egg. In addition, there is no prominent changes in the morphological architecture of fertielized eggs which has been exposed to dbcAMP as revealed by electron microscopic observation. Consequendy, it can be concluded that the mouse cocytes once inhibited their maturation by dbcMP may retain, in some extent, the fertilizability, although most of the fertilized egg may not proceed to further development because of the failure of pronucleus formation.

• Animal Bioscience
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• v.34 no.11
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• pp.1870-1878
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• 2021

Objective: The objective of this experiment was to investigate the effects of different colors produced by light emitting diode (LED) on Brown Tsaiya ducks. Methods: A total of 144 female Brown Tsaiya ducks were randomly allocated into three individual cage rearing chambers with different LED illumination colors as treatments. Three different treatments were: i) white color, ii) blue color, and iii) red color. The experiment periods were from ducks 21 to 49 weeks of age, determined traits included i) egg laying performance, ii) feed intake, iii) egg shell breaking strength, iv) egg shell thickness, v) egg Haugh unit, vi) egg weight, vii) serum Estradiol and Progesterone concentration, and viii) behavior pattern. Results: The results indicated that when compared with white and blue color, red color could stimulate ducks sexual maturation and raised the egg laying performance. The red light group was also observed to have the highest feed intake among three treatments. The blue treatment had the lowest egg shell breaking strength and the highest egg weight among three treatments, nevertheless, no significant difference was observed among three treatments on egg shell thickness and egg Haugh unit. The red light group had higher serum estradiol concentration than the white and blue groups, but no significant difference among treatments on the serum Progesterone concentration was found. The results of behavior pattern indicated that red light group showed more feeding and less resting behavior compared to the blue light group. Conclusion: We found a potential of applying red light illumination in the indoor laying duck raising system with positive results on egg laying performance and acceptable egg weight, equivalent egg qualities compared to white and blue light.

• Development and Reproduction
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• v.25 no.3
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• pp.157-171
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• 2021

To determine whether the reproductive processes of sea bass, Lateolabrax japonicus, proceed normally after transportation from an outdoor net-cage into indoor tanks, we examined changes in the gonadosomatic index (GSI), histological gonadal tissue, and plasma levels of sex hormones (testosterone and estradiol-17ß) during their annual reproductive cycle. We also measured maturation and spawning across two sea water salinity levels (full and low salinity). Fecundity was estimated by the relationship between egg number and body size in female sea bass. Monthly changes in the GSI, histological gonadal tissues, and oocyte size showed both male and female sea bass reach final maturation in January and February, respectively, indicating that the spermiation of males occurs earlier than the spawning of females. The histological results indicated that the sea bass is a multiple spawner, similar to many marine teleosts, exhibiting group-synchronous oocyte development. Female maturation and spawning were enhanced in lower salinity seawater (29.6-31.0 psu) compared to that of normal salinity (34.5-35.1 psu). These results confirm that sea bass reproduction can occur successfully in captivity and imply that fertilized eggs can be collected from February to March. Additionally, our results show that lower salinity enhances oocyte maturation and spawning of female sea bass.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.2
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• pp.112-117
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• 2005

Sargassum fulvellum (Turner) C. Agardh, an edible brown alga is farmed commercially by sexual reproduction and vegetative regeneration. Investigations were made on the phenology, abundance and maturity of reproductive structures in mature fronds, egg release and young germling development under different light conditions (20, 50, 80 and $100{\mu}mol/m^2/s$) and temperatures (5, 10, 15, 20 and $25^{\circ}C$). Monthly sampling was carried out by SCUBA diving at Chungsando on the southwestern coast of Korea from September 2002 to August 2003. The Maximum length of thalli was $104.6{\pm}20.7{\cal}cm$ in March 2003 when the water temperature was $9.0^{\circ}C$ and minimum was $0.8{\pm}0.5{\cal}cm$ in June when the water temperature was $19.5^{\circ}C$. Receptacle formation was observed from February to April. The peak period of egg release for this alga was in April when the water temperature was about $10^{\circ}C$ in nature. In the culture regimes of temperature and irradiance, the egg release of the excised female receptacle was highly affected by temperature. The maximum rate of egg release was $96.7{\pm}5.8{\%}$ under $20^{\circ}C$ and $80{\mu}mol/m^2/s$. The maximum length of young germlings was $3.9{\pm}0.2{\cal}mm$ after 35 days culture under $15^{\circ}C$ and $80{\mu}mol/m^2/s$.