• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.5
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• pp.637-644
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• 2014

Two Chionoecetes crabs, C. opilio and C. japonicus are primary targets of trap fisheries in the East Sea. To promote the sustainable management of these species, we investigated their reproductive biology and spatial distribution based on samples collected in standardized traps in the coastal waters of eastern Korea from September 2007 to August 2008. The estimated spawning season of C. opilio was March-April, whereas that of C. japonicus continued year-round. The estimated molting period of both species was September-October. Fecundity of C. opilio was proportional to female, size, ranging from 44,791 to 151,538 eggs, and the estimated body size at 50% sexual maturity was 63.9 mm carapace width. Egg bearing female C. opilio were mostly collected depths of 200-300 m, particularly off Hupo and Chuksan, suggesting that these areas are their major spawning grounds. In contrast, female C. japonicus were mostly collected at depths of 400-600 m, peaking at 600 m. The species-specific catch rate was higher for C. opilio above 400 m, similar at ca. 450 m, and higher for C. japonicus below 500 m. These vertical differences indicate apparent spatial segregation of the species, suggesting that spatially-explicit fisheries management plans may be necessary for mitigating conflicts between the respective crab fisheries and maintaining these crabs.

• Journal of the Korean Home Economics Association
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• v.48 no.2
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• pp.135-144
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• 2010

This study explores whether or not marriage and other family values operate as factors that influence the willingness of women to voluntarily remain ever-single. The study includes as variables the sub-fields of marriage and family values that consist of traditional gender role awareness, freedom in sexual attitude, open outlook on marriage, familism, an acceptance of diverse families, fear of marriage, and assignment of value to extramarital factors. Participants of this study were 259 women in their twenties to forties with no experience of marriage, which were selected from the data used in the Korean Women's Development Institute's Investigation of Single Households(2007). Upon inserting value-related variables and sociodemographic variables into a binomial logistic model for analysis, age, open outlook on marriage, assigned value on extramarital factors, and an acceptance of diverse families were shown to be factors influencing the willingness of women to remain ever-single. That is, as the age spectrum is lower, outlook on marriage is open, more values are granted on the extramarital factors, and the degree of an acceptance of diverse views on family is higher, the chances that women would remain ever-single voluntarily were shown to increase.

• Journal of Plant Biology
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• v.36 no.2
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• pp.159-170
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• 1993

We investigated the effects of maternal and paternal parentage, and ovule position in a pod on seed development, weight, and progeny performance, using an annual crop commonly called cowpea (Vigna unguiculata L.). The experiment was conducted in a greenhouse. Nine maternal parents were randomly selected, and 3 individuals were chosen as paternal parents based on the male fitness components. Five types of hand-pollination were attempted on each flower of the maternal plants to evaluate the influence of paternal identify. Independent variables such as parentage and ovule position affected the pattern of seed development. Ovules in the middle position of the pod exhibited a much higher probability of seed maturation than those at the stylar and basal positions, confirming the position effect. These independent variables also appeared to exert a significant effect on seed weight, although it was not possible to evaluate the relative importance of those variables due to a significant interaction between parents. Mixed pollination tended to yield heavier seeds than other paternal parents. Ovules in the middle and basal end positions produced heavier seeds than those at the stylar end regardless of maternal and paternal parentage. Seed weight was independent of all measurements of progeny performance. At week 2 after germination significant paternal effects were found to be mediated through the ovule position in a pod. In particular, the progeny derived from self-pollination performed worse than the progeny from other paternal parentage. The progeny performance at week 4 after germination was affected by maternal parents independently of seed weight. These results show that paternal and maternal effects were quite consistent from the seed development to early growth of the progeny. Consequently, maternal and paternal effects on seed development and weight, and progeny performance may reflect, at least to some extent, genetic contribution of both parents. If so, it is possible for sexual selection on maternal and paternal function to generate the evolution of reproductive traits related to seed production.

• The Korean Journal of Malacology
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• v.25 no.2
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• pp.105-112
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• 2009

We investigated the degree of obesity, histological development stages of gonads and sexual maturation induction rates of comb pen shell, Atrina pectinata, per the type of micro-algae supplied. Terms of maturation by singular or mixed supply of microalgae, it was found that maturation of the female was the quickest at 60.0% by the Tetraselmis tetrathele (Tet). experiment group followed by 57.1% by the Chlorella ellipsoidea (Chl). experiment group and 16.7% by the Phaeodactylum tricornutum (Pha). experiment group. However, there were no significant differences between Tet. experiment group and Chl. experiment group. As for the male, maturation was the quickest at 60.0% by the Tet. experiment group followed by 16.7% by the Chl. experiment group and 14.3% by the Pha. experiment group. In light of these results, Tet. is concluded to be a very useful feed organism in breeding the mother comb pen shells. Upon completion of the experiment, the sexual maturation induction rate for the female was found to be the highest at 82.0% in the Tet. experiment group followed by 72.0% by the Chl. experiment group, 64.0% by the Pha. experiment group and 58.0% by the mixed micro-algae experiment group. During the period of experiment, the survival rate was the highest at 94.4% by the mixed micro-algae experiment group followed by 90.0% by the Pha. experiment group, 83.1% by the Tet. experiment group and 78.8% by the Chl. experiment group.

• Development and Reproduction
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• v.6 no.2
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• pp.111-115
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• 2002

5-Hydroxytryptamine(5-HT; serotonin) system has been implicated in the modulation of male sexual behaviors and the secretion of reproductive hormones. In human males, selective serotonin re-uptake inhibitors(SSRIs) are known to improve the major male sexual dysfunction, premature ejaculation, through the central nervous system-mediated pathways. As numerous hormone and local factors, 5-HT may have peripheral role in the regulation of male sexual function. The expression of 5-HT receptor subtypes in the target tissue, however, has not been explored yet. The present study was undertaken to test whether the 5-HT receptor subtypes are expressed in the reproductive tissues of male rat, especially in ejaculatory machinery such as seminal vesicle and vas deferens. To do this, reverse transcription-polymerase chain reaction(RT-PCR) and Southern blot analysis were employed. The transcripts for the 1A, 1B and 2C subtypes of 5-HT receptor were amplified in all the tested tissues. The present study demonstrated the expression of 5-HT receptor in the rat ejaculatory machinery, suggesting that 5-HT may play a pivotal role in the male sexual function via not only central pathway but also peripheral route. Further study on the receptor subtype-specific effect and their harmonized mode of action will be needed to establish the understanding of ejaculation mechanism and drug design.

• International Journal of Industrial Entomology and Biomaterials
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• v.34 no.2
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• pp.23-31
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• 2017

Bumblebees, more efficient than honeybees, provide important services for pollination especially in tomato, pepper, cucumber, strawberries and other crops grown under tunnel farming or glasshouse conditions to yield maximization. These bees require pollen and nectar to meet their dietary needs and maintain their colony structure, development and reproduction. Keeping in view their economic importance, the effect of five concentrations of sugar and honey solutions (1:1, 1:1.5, 1:2, 2:1,1.5:1) each as alternative to nectar were used to observe their effect on life history parameters of Bombus terrestris. The 1:1 ratio of sugar solution was found most effective followed by 1.5:1, 1:1.5, 1:2 and 2:1 and also more effective of all five concentrations of honey solutions on all three stages of colony development i.e., at colony initiation, colony development and colony maturation stages. At colony initiation stage, early pre-oviposition period ($6.40{\pm}0.97$ days), early emergence of first worker in the first batch ($25.40{\pm}1.21$ days) and maximum numbers of workers ($6.20{\pm}0.24$) emergence in the first batch were observed at 1:1 ratio of sugar solution. Colonies reared on 1:1 ratio of sugar solution reached earlier ($52.13{\pm}1.28$ days) at colony foundation stage with minimum mortality ($3.27{\pm}0.54$ workers). At colony maturation stage, maximum numbers of workers, sexual (males, queens) and maximum mother queen longevity was observed at the same 1:1 ratio of sugar solution. It can be suggested from present study that sugar solution as alternative of nectar at 1:1 ratio was better than other sugar concentration levels and also from those of honey solution.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.454-461
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• 2017

This study was conducted to investigate the optimal conditions for spore germination, prothallus propagation, sporophyte formation, and seedling growth in Polystichum braunii (Spenn.) $F{\acute{e}}e$. The rate of spore germination and early prothalium development was high in Knop (41.2%), which had low mineral content. The optimal medium for prothallus propagation and sexual organ formation was 2MS medium (2% sucrose). Among the various mixtures of cultivation soil (bedding soil, peat moss, perlite, and decomposed granite), a mixture of bedding soil and decomposed granite at a ratio of 2:1 (v:v) had a positive effect on sporophyte formation (276.3 ea/$7.5m^2$). The most efficient conditions for promoting the growth of sporophytes were pots filled with only bedding soil.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.12
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• pp.1832-1842
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• 2007

Cytochrome P450 aromatase is responsible for the biosynthesis of estrogen. It is also responsible for the endogenous production of 19-nortestosterone (nandrolone), an anabolic androgen unique to pigs. Plasma concentrations of 19-nortestosterone are highest between two and four weeks after birth in male pigs. In the present study, the physiology of 19-nortestosterone was investigated by measuring the mRNA levels of steroidogenic enzymes, estrogen receptors and androgen receptor in the tissues of growing pigs. The expression of aromatase, 17${\alpha}$-hydroxylase and 3${\beta}$-hydroxysteroid dehydrogenase in the testes of male piglets increased between birth and two weeks of age, and then decreased progressively. Similar developmental expressional patterns were observed for 17${\alpha}$-hydroxylase and 3${\beta}$-hydroxysteroid dehydrogenase in the ovaries of female piglets, but without significant aromatase expression. The major form of aromatase expressed in the testes of piglets was identified as type I. Expression of estrogen receptor-${\alpha}$ and -${\beta}$and androgen receptor genes was also detected in both testes and ovaries. A transient elevation of androgen receptor mRNA in male piglets at two weeks of age was also observed in testes. Significant expression of the androgen receptor gene, but not of estrogen receptor-${\alpha}$ and -${\beta}$ genes, was also demonstrated in adipose tissue and muscle. We conclude that the observed increase in the testicular expression of aromatase in male pigs could account for the production of large amounts of 19-nortestosterone at between two and four weeks of age in males. Androgen receptor and 19-nortestosterone appeared to be important for testicular development and might contribute to sexual dimorphism in body composition and muscle development in juvenile pigs.

• Journal of Aquaculture
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• v.2 no.1
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• pp.21-32
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• 1989

This study was undertaken to understand development stage of ovary and changes of hormone concentrations in the Israeli carp, Cyprinus carpio from Ferbruary to May. The results obtained in these experiments are as follows: 1. Serum LH levels began to increase sharply in March, coinciding with the onset of rapid ovarian development. 2. LH levels were well correlated with changes in gonadosomatic index. 3. Dramatic increase in gonadosomatic index occured during the months of March. 4. Ripe stage(Stage VII) rapidly increase in March. 5. Early perinucleolus oocyte rapidly develop into late perinucleolus oocytes in March. 6. The vitellogenic phase begins as these late perinucleolus oocytes become transformed into early maturing oocytes through the accumulation of yolk. 7. The cytoplasm completely fills with yolk as oocytes reach the late maturing stage. 8. Changes in the microscopic appearances of the ovaries were well correlated with changes in both gonadosomatic index and macroscopic appearance. 9. It is concluded from these observations that LH plays a major role in sexual maturating of the Israeli carp.

• The Plant Pathology Journal
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• v.21 no.4
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• pp.317-321
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• 2005

Since 2000 severe rots on aerial and underground parts of paprika (Capsicum annum L.) has occurred in most surveyed glasshouses throughout the country. A total of 56 isolates of a fungus were consistently isolated from various plant parts such as fruit, stem, branch, and root collected from 16 farms in five provinces. Anamorph stage of the fungus was identified as Fusarium solani based on its morphological characteristics. However, the fungus readily produced a sexual structure of perithecia on infected plant tissues and on agar media. Since the fungus formed abundant perithecium by a single isolate, it was considered as a homothallic strain of Nectria haematococca, the teleomorph of F. solani. Irregularly globose perithecia with orange to red color formed sparsely to gregariously on dead tissues of fruits and basal stems at the late infection stage, which is a diagnostic sign for the disease. Perithecia ranged from 125 to 220 ${\mu}m$ in diameter varied among isolates. Asci enveloping eight ascospores were cylindrical and measured 60-80x8-12 ${\mu}m$. Ellipsoid to obovate ascospores are two-celled and measured 11-18x4-7 ${\mu}m$. Ascospores were hyaline, slightly constricted at the central septum, and revealed longitudinal striations that is characteristic of the species. This fungus that has never been reported in Korea has previously become a threat to paprika cultivation because of its strong pathogenicity and nationwide distribution.