• Ocean and Polar Research
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• v.28 no.2
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• pp.201-207
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• 2006

We studied variation in clutch size, hatching, fledging and breeding success of the Black-tailed Gull (larus crassirostris) at Hongdo Island, which supported the largest breeding colony of the species, in South Korea in 1997 and 2000 to 2003. Cluck size was recorded in 1,388 nests and breeding success was estimated in 83 nests. Mean clutch size was 1.89 t 0.65. A total of 63.9% of the eggs hatched and 53.5% of the chicks survived until fledged. Breeding success was 34.2%. Causes of breeding failure were eggs missing (14.9%), rotten eggs (15.5%) and predation (2.4%) during the incubation period and chicks missing(35.8%), starvation (7.4%) and pecked chicks (3.2%) during the chick rearing period. In 2002, the main causes of breeding failure were eggs missing (17.2%) and rotten eggs (6.9%) during the incubation period and missing chicks (15.5%), starvation (3.5%) and pecked chicks (6.9%) during the chick rearing period. Most chick mortality occurred within three days after hatching.

• The Plant Pathology Journal
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• v.20 no.3
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• pp.165-171
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• 2004

A total of 62 isolates of Bipolaris cactivora causing cactus stem rots were isolated from major cactus-growing areas in Korea. Colony morphology of the isolates on potato-dextrose agar was differentiated into aerial (CA) and non-aerial mycelial types (CB). CA had profound aerial mycelium with grayish brown (CA-l), light brownish (CA-2), and brownish (CA-3) pigmentations; respectively, while CB had dark brownish pigmentations. CA had conidia of less dark pigmentation and acute terminal end. CB had darker and more round-end conidia. Twenty-eight amplified fragments were produced by polymerase chain reaction (PCR) with a set of 2 random primers. The sizes of amplified DNA fragments ranged approximately from 0.1 to 2.3 kb. The isolates were classified into 2 major genomic DNA random amplified polymorphic DNA (RAPD) groups at the genomic similarity of 97.7％ and 95.1％, respectively. Cluster analysis of genetic similarity among the isolates generated a dendrogram that clearly separated all isolates into SA or SB. This result suggests that there may be two morphotypes of B. cactivora in Korea that may differ in their genetic constitutes.

• Korean journal of applied entomology
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• v.16 no.2 s.31
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• pp.105-113
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• 1977

In this paper have been examained the relation of tssk performance to body size. the variation of venation of males, sex ratio, breeding by forms of worker's pupae and structure by forms of workers's colony to nest size in polymorphism of polydomous red wood ant, Formica rufa truncicola var. yessoensis Forel in Korea. 1. The workers are classified into three forms, in which small form mainly performs itself the task of nursing in the nest and the visit to aphid from the outside of the nest, medium and large form mainly do not only the stinct of prey carrying from the outside of the nest and nest structure, but the task of protecting colony of outside. But the small forms visiting to aphid is not always fixed but seems to be changed with season. 2. The variation forms of venation of males are fourteen, generally, they have various variations of the discoidal. 3. Generally, sex ratio of Formica rufa truncicola var. yessoensis Forel is the same proportion, but it seems that there are some difference according to its characteristic of colony in each nest and polydomous colony structure in its habitat. 4. In summer season the medium form makes a colony in high proportion without any relations with the size of nest but. during hibernation, small form coasists in small nest, medium in medium nest and large in large nest. And so the structure of worker's colony by forms according to their nest size seems to be changed with season.

• Animal cells and systems
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• v.15 no.1
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• pp.85-90
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• 2011

In 2001, we conducted a study to assess the effects of differential arrival times and nest-site selection on reproductive performance in a mixed-species heronry consisting of six species in Taeseong-ri, Chungbuk, Korea. We recorded the arrival dates, nest heights, clutch sizes, and brood sizes after 15-20 days of the age of the birds' chicks. The grey herons and cattle egrets arrived first and last, respectively, on the colony site. In the homogenous vegetation structure of the breeding site, the pitch pine trees (Pinus rigida) were mainly used for building nests on 48 of the 50 pine trees (96%). The breeding species vertically stratifies the nest sites according to their body size, except for the cattle egrets and black-crowned night herons that nested at sites higher than those predicted from their body size. The mean nest success rates of the six species under study were positively correlated with the mean nest heights. Our findings suggest that aggressive interspecific interactions among neighbors influence nest-site selection to enhance breeding success.

• Journal of Animal Science and Technology
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• v.57 no.3
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• pp.7.1-7.7
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• 2015

To meet the increasing demands of specific pathogen free (SPF) minipigs in biomedical researches, 8 pregnant Chinese Wuzhishan minipigs (WZSP) sows with clear background were chosen to obtain SPF WZSP by hysterectomy. At $111{\pm}days2$ of the pregnancy, piglets were aseptically taken out from the sows and artificially suckled for 40 to 45 days in the positive isolators. Then, the piglets defined as F0 were transferred to barrier environment and fed with standard feeds. The original SPF colony was formed for breeding by selected piglets from F0 group of 6-8 months old. Biological characteristics of SPF WZSP were collected and further compared to those of conventional (CV) WZSP, including growth performance, reproductive performance, hematology and blood biochemistry, and major pathogens detection. As a result, 61 F0 piglets were obtained from 8 candidate sows, and 55 out of them survived. After strictly selection, 35 F0 piglets were used to form the original SPF colony, which produced 14 litters of SPF piglets defined as F1. Piglet survival rates, growth performance, and reproductive performance of SPF WZSP were similar to CV WZSP. Some hematology and blood biochemistry parameters showed significant differences between SPF and CV WZSP. Eighteen kinds of pathogens were identified to be free in F0 and F1 SPF colony by repeated pathogen detections. In conclusion, we established a satisfied SPF WZSP colony maintaining original characteristics, free of controlled diseases, and being proved to be a suitable laboratory animal.

• Korean Journal of Environmental Biology
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• v.35 no.2
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• pp.134-142
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• 2017

Nando Island is reported as one of the biggest breeding colonies of seabirds in South Korea, and is protected as a Natural Monument. This study was conducted between July to November 2015, to investigate the breeding population of Black-tailed gulls and their habitat on Nando Island. We estimated the breeding population of Black-tailed gulls (Larus crassirostris) using nest density. The mean nest density of Black-tailed gulls was $0.51\;per\;1m^2$ ($0.51m^{-2}$), and the breeding population was approximately 26,760 individuals. The dominant vegetation was Echinochloa crusgalli and Agropyron tsukushiense var. transiens, which served as shelter and nest sites to Black-tailed gulls. The diet of Black-tailed gulls was mainly the fish, Japanese Anchovy Engraulis japonicas (48%). Other species which were found to breed on Nando Island were Streaked Sheawater (Calonectris leucomelas), Temminck's Cormorant (Phalacrocorax capillatus), and Swinhoe's storm petrels(Oceanodroma monorhis).

• Current Research on Agriculture and Life Sciences
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• v.19
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• pp.17-22
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• 2001

The study was conducted to establish the method of performance test of honeybee queens under Korean environment. Colony performances of Apis mellifera were tested based on wintering ability, colony population and honey yield in Sangju, Korea from November, 1999 to October, 2001. The results of performance-testing on the honeybee colonies are summarized as follows: The colony weights measured before and after wintering in 1999~2000 season were averaged $22.6{\pm}2.6kg$ and $20.1{\pm}2.6kg$, respectively, showing the decrease of $2.5{\pm}0.7kg$. During 2000~2001 winter season, the colony weight before wintering was $22.6{\pm}2.3kg$ and was decreased by $2.3{\pm}0.6kg$. The number of combs well covered with bees was $13.1{\pm}4.6$ as measured on the 22nd of May. 2000 and $16.0{\pm}3.8$ on the 21st of May. 2001, respectively. The rate of supering colonies were 50% and 98.5% in 2000 and 2001, respectively. The amount of honey production was $12.7{\pm}8.6kg$ per colony in 2000, and $14.2{\pm}7.6kg$ per colony with unselected queens and $23.5{\pm}4.9kg$ per colony with selected-tested queens in 2001, which were harvested two times during main nectar flow season of black locust, Robinia peseudoacasia.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.10
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• pp.1500-1507
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• 2016

Myostatin (MSTN) can negatively regulate the growth and development of skeletal muscle, and natural mutations can cause "double-muscling" trait in animals. In order to block the inhibiting effect of MSTN on muscle growth, we transferred zinc-finger nucleases (ZFN) which targeted sheep MSTN gene into cultured fibroblasts. Gene targeted colonies were isolated from transfected fibroblasts by serial dilution culture and screened by sequencing. Two colonies were identified with mono-allele mutation and one colony with bi-allelic deletion. Further, we introduced the MSTN-ZFN mRNA into sheep embryos by microinjection. Thirteen of thirty-seven parthenogenetic embryos were targeted by ZFN, with the efficiency of 35%. Our work established the technical foundation for generation of MSTN gene editing sheep by somatic cloning and microinjection ZFN into embryos.

• Journal of Mushroom
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• v.2 no.1
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• pp.33-37
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• 2004

To develop neohaplonts for Ganoderma breeding, protoplasts were isolated from dikaryotic mycelium and regenerated. Selection rate of neohaplonts varied between ASI7074, ASI7091, ASI7094, ASI7100 and ASI7115, showing 5.24% on the average. Auxotropic mutants from Ganoderma monokarions were recovered by UV irradiation on protoplasts. Protoplast survival rates were 1.9% ASI 7074, 0.17% ASI 7091, and zero percent ASI 7100 using 300 second irradiation. Four auxotrophic strains were recovered from 1,536 colonies screened that will be further utilized for protoplast fusion and transformation.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.371-382
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• 2020

The A, C, F colonies of Apis mellifera ligustica Spin. and D, V colony of Apis mellifera caucasia Gorb. bees were collected from 2005-2007. Consequently, inbred lines were derived from the bees of original colonies by matting in the isolated island with due regard for pure breeding. This project helps in the selection of colonies with higher production capacity, aiming to improve honey and royal jelly production and breeding programs. Twenty-three standard morphological traits of honeybee were evaluated, and samples were compared with the data of the two original subspecies. The result suggested that 8 traits partly preserved in bees of inbred lines, and the bees from A. m. ligustica preserved more traits than bees from A. m. caucasia. Among the studied inbred lines, the F line is distinguished by an increase in leg parameters, considered as a favorable phenotypic trait of inbred lines. Importantly, bred of beelines in the same area can be classified as remote and isolated areas. Therefore, we observed differences of inbred lines with the origin subspecies in description acquired with morphometric characteristics as a result of adaptation, breeding, purebred individual lines used as an important resource for breeding novel cross-breeding colonies.