• International Journal of Industrial Entomology and Biomaterials
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• 제11권2호
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• pp.93-98
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• 2005

Studies on extended egg preservation schedule from 120 days to 180 days was taken up with 20 germplasm accessions of mutant silkworm genetic stocks of Bombyx mori L. Statistical analyses of the data collected over three trials revealed no significant changes both in the qualitative and quantitative traits of the genetic stocks between treatment (6 months egg preservation) and control (4 months egg preservation), except for fifth instar larval duration in TMS-61, TMS-62, TMS64, TMS-31 and TMS-34 shell weight in TMS-62, TMS-64 and TMS-66. Thus, the results indicate that extended schedule of 6 months egg preservation can safely be adopted, which will reduce the cost of conservation and minimize the genetic erosion owing to reduced crop cycle.

• 한국잠사곤충학회지
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• 제39권2호
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• pp.119-133
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• 1997

Isozyme was used to characterize general protein patterns of genetic relationships among 303 silkworm stocks preserved in National Sericultural and Entomology Research Institute, RDA. Six isozymes (esterase, acid phosphatase, alkaline phosphatase, amylase, glucose-6-phosphate dehydrogenase and sucrase) from hemolymph, midgut, and digestive juice were employed to construct dendograms(UPGMA method) using a polycrylamide gel electrophoresis. A cluster analysis revealed four major group, which were divided into several subgroups within each group, contained assemglages of Japanese and Chinese races. Especially, genetic differentiation in the first and second group was greatest rather than within Japanese and Chinese races repectively and was concordant with the hypothesis of phyletic sorting of initial variability in China many years ago. Hypothesized recent introgression between groups was also plausible, but the eviednce suggested bidirectional gene flow between the Chinese and the Japnaese lineages. Interpreting the results in light of evidence from the current study, the genetic diversity and relationship showed in Korean silkworm race, Hansammyun reflected early and independent evolution from the Chinese ancestor, limited addition of new variability and phyletic sorting within Korean peninsula more than 4,000 years.

• International Journal of Industrial Entomology and Biomaterials
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• 제9권1호
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• pp.35-40
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• 2004

Bombyx mori densonucleosis virus type 1 (BmDNV1)- a non occluded virus causes flacherie disease in the susceptible stocks of the silkworm, Bombyx mori. However, some stocks are non-susceptible. Non-susceptibility to BmDNV1 in B. mori is a unique case where the virus infection is completely inhibited by a single gene of the host. A survey conducted by this institute in some parts of Karnataka state has revealed that, 43.05% of the total incidence of flacherie disease caused by non-occluded viruses, are due to the synergistic infection of B. mori densonucleosis and infectious flacherie virus. Earlier study indicated that rearing of BmDNV1 resistant silkworm stock is effective in protecting silkworm against BmIFV also. In the present study the response of 78 silkworm stocks which include 42 of non-diapausing and 36 of diapausing groups, to BmDNV1 is investigated. Newly ecdysed third instar larvae were inoculated per-os with 10% inoculum of BmDNV1 extracted from the mid-gut of infected silkworm. One non-diapausing and three diapausing silkworm stocks were found to be resistant to BmDNV1. Eleven silkworm stocks were found to possess moderate resistance whereas rest sixty three were found to be susceptible to BmDNV1. Genetic analysis has shown that the resistance to BmDNV1 is autosomally inherited and controlled by a major dominant or a major recessive gene in different silkworm stocks. These resistant stocks can be utilized as the resource material to develop BmDNV1 resistant commercial hybrids. The selection strategies, depending upon the mode of inheritance of resistance in the resource material chosen, are discussed.

• International Journal of Industrial Entomology and Biomaterials
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• 제19권1호
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• pp.205-213
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• 2009

In order for further systematic maintenance of silkworm stocks kept in Korea we analyzed character quality of a diverse array of silkworm strains originated from several sericulture-practicing countries. The analysis of about ten qualitative characters from 67 strains (13 of Japanese strains, 15 of Chinese strains, 14 of European strains, 6 of Korean and Tropical strains, and 19 of unknown origin) revealed a significant difference in the ten different qualitative characters among silkworm strains. In the analysis of quantitative characters, Japanese and European strains were highest in hatchability, the Korean and Tropical strains were highest in pupation rate, and unknown origin and Chinese strains were highest in cocoon yield and number of egg laid. With the connection of molecular genetic analysis the current data may provide the advanced ground for further systematic maintenance of valuable genetic resources of silkworms, although more breeds should be investigated for further complete pictures.

• 한국어류학회지
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• 제21권4호
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• pp.221-226
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• 2009

넙치 양식에 이용되는 종묘는 수 세대에 걸친 양식용 어미로부터 생산된 것으로 알려져 있어 넙치 양식 집단의 유전적 다양성은 자연 집단에 비해 크게 낮을 것으로 추정되고 있다. 본 연구는 우리나라에서 양식되고 있는 양식 집단의 유전학적 다양성이 어느 정도인지를 파악하기 위하여 6개의 microsatellite DNA marker를 이용하여 자연 집단과 비교하였다. 본 조사에서 관측된 유전자좌별 대립유전자 수의 범위는 9~27개였으며, 6개의 유전자좌에 따른 각 집단별 평균대립유전자 수는 자연 집단이 19.7~21.8개, 양식 집단이 12.0~14.7개로 나타나, 자연 집단이 21.1개로 양식 집단의 전체 평균 9.4개보다 높게 나타났다. 조사된 집단들의 이형접합체율(Ho)의 범위는 0.722~0.959이었으며, 유전자좌별 Ho의 범위는 자연 집단에서 0.755~0.918, 양식 집단에서 0.722~0.959로 자연 집단과 양식 집단 간 커다란 차이는 없었다. 각 유전자좌에 대한 집단별 Markov chain procedure test를 한 결과, 자연 집단에서는 HWE를 따르는 것으로 나타났으나, 울진 및 완도 양식 집단의 일부 마커들에서 세대를 거듭하면서 양식 집단의 유전학적 조성 등이 유전적 평형에서 벗어나고 있는 것으로 나타났다(P<0.05). 또한 자연 집단인 추자 집단이 양식 집단과 유전적 거리가 가깝게 나타남으로써 방류된 개체들이 상당 부분 자연 집단의 일부로 자리 잡아 자연 집단의 유전적 조성에 영향을 주는 것으로 판단된다. 따라서 양식 집단의 유전적 다양성 회복 및 자연 집단의 유전적 조성의 유지, 보호 등에 대한 지속적인 연구가 필요한 것으로 생각된다.

• Journal of Plant Biotechnology
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• 제32권1호
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• pp.45-50
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• 2005

바이러스에 감염된 감귤나무를 생육상에서 주간 $40^{\circ}C$, 야간 $30^{\circ}C$로 열처리한 후 발생한 신초를 $0.3\~0.7\;\cal{mm}$ 로 잘라내어 기내에서 치상한 탱자 (P. trifoliata) 대목에 접목하는 열처리와 경정접목 (shoot-tip grafting)을 병행한 방법으로 무독묘 생산에 성공하였다. 감글 바이러스 즉, citrus tristeza virus (CTV), satsuma dwarf virus (SDV) and citrus tatter leaf virus (CTLV) 에 대한 무독화율은 각각 $75.7\%,\;100.0,\%\;82.6\%$ 였다. 경정접목 시 접수크기는 $0.3\;\cal{mm}$ 이하 일때 바이러스 무독화율이 높았으나 절목 후 활착율은 저하되었다. 열처리 후 경정배양 (shoot-tip culture)을 하여 1 개월 후에 활착율을 조사한 결과 Yuzu (C. junos)는 $74.6\%$, 그리고 early satsuma mandarin (Iwasagi)은 $13.3\%$를 나타내었다. 그러나 항바이러스제인 rivabirin을 첨가한 후 무독효과를 보기 위하여 후대배양 중에 온주밀감의 특성상 갈변되어 고사함으로서 무독묘를 생산하지 못했다.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2002년도 제45회 춘계 학술연구 발표회
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• pp.40-40
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• 2002

• Asian-Australasian Journal of Animal Sciences
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• 제25권2호
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• pp.170-176
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• 2012

Genetic diversities, population genetic structures and demographic histories of the thread-sail filefish Stephanolepis cirrhifer were investigated by nucleotide sequencing of 336 base pairs of the mitochondrial DNA (mtDNA) control region in 111 individuals collected from six populations in Korean coastal waters. A total of 70 haplotypes were defined by 58 variable nucleotide sites. The neighbor-joining tree of the 70 haplotypes was shallow and did not provide evidence of geographical associations. Expansion of S. cirrhifer populations began approximate 51,000 to 102,000 years before present, correlating with the period of sea level rise since the late Pleistocene glacial maximum. High levels of haplotype diversities ($0.974{\pm}0.029$ to $1.000{\pm}0.076$) and nucleotide diversities (0.014 to 0.019), and low levels of genetic differentiation among populations inferred from pairwise population FST values (-0.007 to 0.107), support an expansion of the S. cirrhifer population. Hierarchical analysis of molecular variance (AMOVA) revealed weak but significant genetic structures among three groups ($F_{CT}$ = 0.028, p<0.05), and no genetic variation within groups (0.53%; $F_{SC}$ = 0.005, p = 0.23). These results may help establish appropriate fishery management strategies for stocks of S. cirrhifer and related species.

• Animal cells and systems
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• 제16권1호
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• pp.41-49
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• 2012

Eighteen new polymorphic microsatellite markers were developed for the Korean mi-iuy croaker ($Miichthys$ $miiuy$, Perciformes, Sciaenidae), and allelic variability was compared between a wild population in Mokpo, Korea, and a hatchery population in Tongyeong, Korea. All loci were amplified readily and demonstrated allelic variability, with the number of alleles ranging from 5 to 37 in the wild population, and from 4 to 12 in the farmed population. The average observed and expected heterozygosities were estimated, respectively, to be 0.74 and 0.78 in the hatchery population samples, and 0.79 and 0.86 in the wild samples. These results indicate lower genetic variability in the hatchery population compared with the wild population, and significant genetic differentiation between the wild population and the hatchery samples ($F_{ST}$=0.058, P<0.001). These microsatellite loci may be valuable for future population genetic studies, monitoring changes in the genetic variation within stocks in a commercial breeding program, conservation genetics, and molecular assisted selective breeding of the mi-iuy croaker in the future.

• 한국가금학회지
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• 제28권2호
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• pp.155-163
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• 2001

Gene and cell transfer technique will serve as a powerful tool for the genetic improvement of the poultry and to yield useful products. For avian transgenesis, Japanese quail may serve as an excellent animal model because of its small body size and fast growth rate. Recent progress was described on the manipulation of quail embryos such as the introduction of foreign genes and cells, and the subsequent culturing of the manipulated embryos yielding hatchlings. Intraspecific donor-derived offspring have been available in quail, however, further investigation will be required to obtain interspecific offspring with the aim of rescuing endangered species. Trans genesis will also be useful for improving the profitability and quality of poultry stocks and for developing stocks with novel uses. Considerable progress should soon be made toward the production of transgenic poultry. The key feature of the procedure described here is that embryos are initially taken out from the shell for ease of manipulation and then placed back in culture in addition to various operations midway during culture.