• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.30-30
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• 2003

자성발생(gynogenesis)은 대상 어류의 성 결정기작이 암컷 동형접합성(female homogamety)인 경우 전 암컷 단성집단을 생산할 수 있으며, 단기간 내에 우수한 품종의 순계 획득과 유전적으로 동일한 clone 집단을 만들 수 있다(Thorgaard, 1986; 정 등 1996). 이에 제 1 난할 억제에 의한 메기 S. asotus에서의 체세포분열 억제성(mitotic) 자성발생 2배체가 유도된 바 있다(임 등, 2002), 염색체공학 기법 중 웅성발생 2배체(androgentic diploid)는 난자 핵을 불활성 시킨 후 정자 핵에 의해 제 1 난할억제에 의한 유전자 배가로 유도 될 수 있다. 본 연구는 염색체공학에 의한 메기 4배체 생산, 메기체세포분열 억제성 자성발생성 2배체의 효과적인 유도 조건 검정 및 메기 웅성발생성 2배체 생산을 위한 연구의 일환으로, 메기에서의 핵분열(korykinesis)에 관하여 조사하였다. 메기에서의 핵분열 수온 25$\pm$0.5$^{\circ}C$ 조건에서 수정 후 31분에 가장 현저하였다. 본 연구 결과를 Park and Im (2001)의 수온 24$^{\circ}C$에서의 제 1 난할 후기가 50분이며 mitotic interval이 18.5$\pm$1.2분인 결과와 비교시, 본 연구 결과의 수온 24$\pm$0.5$^{\circ}C$ 조건에서 핵분열이 수정 후 31분인 것은 핵분열과 세포질분열(cytokinesis)이라는 관점에서 정확히 일치한다. 염색체 수의 배가시, 핵분열 억제는 세포질 분열 억제에 비해 더욱 효과적으로서(Cherfas et al., 1993; Nam et al., 1999), 본 연구 결과의 핵분열 시간(수온 24$^{\circ}C$ 조건에서의 수정후 31분)을 기반으로 하여 차후, 4배체 메기와 체세포분열 억제성 자성발생 2배체 메기 및 웅성발생성 2배체 메기 유도 및 그의 생산성 향상에 관한 연구가 기대된다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.52-58
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• 1995

5-methyltryptophan（5MT） resistant mutant plants （MRl） were analyzed for characterization of anthranilate synthetase （AS） and tryptophan synthetase （TS） enzymes. The enzyme was measured in crude extracts from MR1 and control seedlings of Danggin inbred line. There was no significant difference in the level of AS between MR1 and control seedlings when grown on MS medium without 5MT. However, MR1 seedlings grown on MS medium with 25mg/L 5MT showed the level of AS twice higher than that of control seedlings. The activity of AS was inhibited to 50％ in untreated plants when 4mg /L L-tryptophan was added to their extracts. Extracts from MR1 plants required about four times higher concentration of amino acid to cause equal inhibition. In the TS assay, the activity observed in MR1 seedlings was four times higher than that of control seedlings. We have also isolated and sequenced the gene which encoding the tryptophan synthetase B subunit （TSB） from maize. The gene encodes polypeptides with high homology to TSB isolated from other plants, and is expressed in all the developmental stages examined. Northern hybridization analysis indicated that the gene expression in MR1 seedlings grown on MS medium showed a higher level than in control seedlings.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2001.11b
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• pp.35-42
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• 2001

In order to obtain basic information for pure line breeding of hemp which is effective on the pure line preservation and propagation, three varieties were investigative from 1995 to 1996 at Mokpo Experiment Station, Honam Agriculture Experiment Station, and cutting parts, cutting times, cutting length and storage duration after cutting of plant were observed. Higher rooting ratio were observed in cutting of shoot and later branch, in July 5, optimum harvesting time and 5 days after harvesting time, in shorter storage duration,0 and 2 days. Also there were the highest rooting ratio increased by from 12% to 16% in shorter cutting of 10cm than 15cm long cutting in shoot, lateral branch and stem cuttings. Hemp cv. Korea showed higher rooting ratio than the other varieties, Japan and Turkey. Therefore, it was concluded that hemp, a dioecious plant, could be effectively propagated for the pure lines by cutting method, especially in cv. Korea.

• Korean Journal of Poultry Science
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• v.41 no.1
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• pp.7-14
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• 2014

Tyrosinase (TYR) gene is located on chromosome 1 in chicken and it is composed of five exons and four introns. TYR gene is described as a key enzyme in melanin biosynthesis. Most examples of complete albinism in chicken have been due to defects in the tyrosinase gene. The association of feather color and sequence polymorphism in the Tyrosinase (TYR) gene was investigated using Korean Native chicken H breed (H_PL), Korean Native chicken L/W breed(L/W_PL) and 'Woorimatdag' commercial chickens (Woorimatdag_CC). From L_PL and W_PL breed analyses, 4 synonymous SNPs (locus G33A, G116A, C217T and C247T) and 2 SNPs (G838A and G958A) were detected in 4th exon and 4th intron of TYR gene respectively. The genotype frequencies for 6 SNPs were compared between L_PL and W_PL and W_PL represented homozygous SNP types in all the analyzed SNP positions while L_PL displayed various SNP types.

• Journal of Animal Science and Technology
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• v.54 no.4
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• pp.267-274
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• 2012

The method of sexing based on differences in the rate of feather growth provides a convenient and inexpensive approach. The locus of feather development gene (K) is located on the Z chromosome and can be utilized to produce phenotypes that distinguish between the sexes of chicks at hatching. To establish the auto-sexing native chicken strains, this study analyzed the genotype frequency of the feathering in domestic chicken breeds. The method of classification of slow- and rapid-feathering chickens was also investigated. In the slow-feathering chicks, the coverts were either the same length or longer than the primary wing feathers at hatching. However, the rapid-feathering chicks had the primary wing feathers that were longer than the coverts. The growth pattern of tail feather also distinctively differed between the rapid- and slow-feathering chicks after 5-days. The accuracy of wing feather sexing was about 98% compared with tail sexing. In domestic chicken breeds, Korean Black Cornish, Korean Rhode Island Red, and Korean Native Chicken-Red had both dominant (K) and recessive ($k^+$) feathering genes. The other breeds of chickens, Korean Brown Cornish, Ogol, White Leghorn, Korean Native Chicken-Yellow, -Gray, -White and -Black had only the recessive feathering gene ($k^+$). Consequently, feather sexing is available using the domestic chicken breeds. Establishing the maternal stock with dominant gene (K-) and paternal stock with recessive gene ($k^+k^+$), the slow-feathering characteristic is passed from mothers to their sons, and the rapid-feathering characteristic is inherited by daughters from their fathers.

• Journal of Plant Biotechnology
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• v.30 no.1
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• pp.47-52
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• 2003

Anthers from several lines of carrot (Daucus carota L.) were plated on the semi-solid B$_{5}$, basal medium supplemented with 2,4-D and NAA at two concentrations, 1.0 and 2.0 mg/L plus 0.2 mg/L BAP (benzylaminop-urine). Anthers of the most lines on the B$_{5}$ basal medium with 2,4-D showed higher percentages of callus formation than those with NAA. Particularly, in line 45477, highest percentages of callus formation (50%) were observed on B$_{5}$ medium with 1.0 mg/L 2,4-D plus 0.2 mg/L BAP. With 1.0 mg/L 2,4-D, two months was sufficient for initiation of callus development. Calli were regenerated into plantlets through embryogenesis onto regeneration medium without any growth regulators. When callus showing yellowish and soft structure was cultured, it yielded green plants at high regeneration rates, The response of anthers in callus induction and plant regeneration was different among lines investigated. Optimal callus induction and plant regeneration could be obtained through manipulating the concentration of growth regulators. Plantlets after transfer to perlite were grown successfully in greenhouse conditions. Anther culture of carrot will be used as a useful breeding tool in future.

• Korean Journal of Plant Resources
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• v.10 no.1
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• pp.100-104
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• 1997

A new baekji(Angelica dahurica Bentham et Hooker) variety, Baekji l, was developed through a pure line selection at the Gyeongbug Provincial RDA during the period of 1990 to 1995. The variety was characterized to have high plant height. Long root length and large root diameter as compared with a check varicty of Bonghwa baekji but emergence date, flowering date and leaf number of Baekji l was similar to that of the check variety, and it was also more tolerant to nematode and heat stress. Peeled root color of Backji l was yellowbrown but number of the lateral root of the variety was greater. The dried-root yield of Baekji l in yield trial, regional adaptation trial and farmer's field trial was always $21\sim31%$ higher than that of the check variety.

• Korean Journal of Poultry Science
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• v.42 no.1
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• pp.15-26
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• 2015

In this study, genotyping was executed by using 27 microsatellite markers for genetic diversity of 469 Korean Native Chickens [20 population, each population is 24 samples but Hanhyup A line is 13 samples). in total 469 samples were collected from National Institute of Animal Science (Korean Native Chicken (NR, NY, NG, NL and NW), Ogye (NO), Leghorn F,K (NF and NK), Black and Brown cormish (NH and NS), Rhode Island Red C, D (NC and ND), Total is 12 populations] and Hanhyup [H line (HH), F line (HF), G line (HG), V line (HV), S line (HS), W line (HW), Y line (HY), A line (HA), total is 8 populations]. [The allele number were observed 5 (ADL0268) to 20 (MCW0127) each markers. Observed heterozygostiy ($H_{obs}$), expected heterozygosity ($H_{exp}$), polymorphism Information Content (PIC) were observed 0.359 to 0.677, 0.668 to 0.881 and 0.646 to 0.869, respectively. Using these markers, the calculated the heterozygote deficit within chicken line ($F_{is}$) value each population from mean 0.117. Phylogenetic tree showing the genetic relationship among 20 population using standard genetic distance calculated from 27 microsatellite markers. genetic distances revealed the closest (0.175) between NC and ND. on the other hand, Farthest genetic distances (0.710) revealed between NF and HV. STRUCTURE analysis and Principal Components Analysis (PCA) showed that results of similar phylogenetic tree. The expected probability of identity values on random individuals (Total population and only Hanhyup line) was estimated at $8.80{\times}10^{-83}$ and $3.87{\times}10^{-117}$, respectively. In conclusion, This study shows the useful data that be utilized as a basic data of Korean Native Chicken breeding and development for commercial chicken industry to meet the consumer's demand.