• Journal of Life Science
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• v.21 no.3
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• pp.341-348
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• 2011

In an effort to gain greater understanding of the maternal lineages of the Jeju native pig (JNP), we analyzed the mitochondrial DNA (mtDNA) CYTB gene and compared it with those of other pig breeds. PCR-RFLP analysis was conducted with six pig breeds including JNP, and then the RFLP patterns allowed for the separation of the pig breeds into two distinct haplotypes (mtCYTB1 and mtCYTB2). The JNP CYTB sequences were detected in both the European and Asian breed clusters on the phylogenetic tree. The J2 group was sorted with the indigenous cluster of Asian pig lineages and was related closely to Chinese native pig breeds, but a second group, J1, was sorted with the European pig lineages and appeared to be related to Spanish Iberian native pigs, rather than to Asian breeds. These results indicate that the JNP currently raised on Jeju Island have two major maternal origins estimated in Asian and European pigs. We concluded that the JNP that share a common lineage with indigenous Asian pigs were domesticated in the distant past, originating from pigs that were already being raised elsewhere at that time, and that the European pig breeds introduced in the twentieth century have also contributed to the formation of this pig population.

• Journal of Life Science
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• v.24 no.6
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• pp.626-632
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• 2014

The genetic structure and phylogenetic relationship were investigated in Korean red spotted grouper populations using the nucleotide sequence polymorphisms of the mitochondrial DNA (mtDNA) cytochrome c oxidase subunit I (COI) gene. The COI gene was sequenced showed 99.1-99.8% identity with the EF607565 sequence previously reported. A total of twenty haplotypes were found, and the Korean population showed nineteen haplotypes. Among those, Hap_03 and Hap_08 showed Jeju-do and China-specific COI sequences, respectively. However, Hap_07 had twelve COI sequences from South Korea and records from Hong Kong and Taiwan. Neighbor-joining (NJ) trees constructed from the phylogenetic analyses based on the polymorphisms of the COI haplotypes showed a monophyletic branching pattern within the genus Epinephelus. This indicated that the red spotted grouper populations had evolved from common maternal ancestors. In addition, the Hap_08, which had the COI sequence recorded only from China Sea, was found in the middle of the NJ tree nearby Hap_07 and showed a close relationship with Hap_07. This indicates that Chinese red spotted grouper is also maternally related to other populations in East Asia. Consequently, East Asian red spotted grouper populations are maternally related, as well as sharing the same evolutionary history, and are still affected by the East Asian ocean current (Kuroshio). These findings help to explain the genetic structure and phylogenetic relationship of red spotted grouper and also contribute to research on artificial breeding and industrialization.

• Journal of Animal Science and Technology
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• v.54 no.4
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• pp.241-246
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• 2012

The goal of this study was to verify the phylogenetic status of the Korean native goats (KNG). We determined the complete sequence of the mitochondrial cytochrome b gene in 48 goats among four populations. We also analyzed genetic variability within goats, and a phylogenetic analysis was performed by comparison with other country's goats. Three nucleotide substitutions were detected, and two of these were missense mutations that occurred due to a substitution of amino acid. Four haplotypes were defined from KNG. Three of these haplotypes were only found in the Chinese goat. However, the other haplotype was KNG-specific. In the phylogenetic analysis, four clades (A~D) were classified among domestic goats, and the KNG was classified into clade 1 that estimated as lineage A based on the D-loop sequence. Each haplotype from the KNG was clustered closely with that of the Chinese goat. The results of haplotype distribution and phylogenetic location suggest that strong gene flow occurred from China to the Korean Peninsula.

• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.287-290
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• 2009

A natural hybrid between the striped spine loach Cobitis tetralineata and the king spine loach Iksookimia longicorpa was genetically identified by sequence analyses of nuclear recombination activating gene 1 (RAG1) and mitochondrial cytochrome c oxidase I (COI) genes. Out of 850 base positions of RAG1, a total of 23 nucleotide substitutions were detected between the two parental species, whereas the electropherogram of the natural hybrid displayed double peaks at all of the 23 positions, which reflects their simple Mendelian inheritance pattern. Meanwhile, comparison of partial sequences of mitochondrial genes (COI in this study), which are well characterized by the maternal inheritance pattern, revealed that the maternal species of the hybrid was C. tetralineata because of their 100% sequence identity.

• Korean Journal of Poultry Science
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• v.13 no.2
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• pp.187-195
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• 1986

This study was conducted to investigate the effects of hatching time on body weights and body measurements in White Plymouth Rock selected for female lines of broiler parents stock, Thirty cockerels were mated to 300 hens and the hatching eggs produced by each hen were pedigreed for sire and dam. The total of 975 chickens were classified into 14 groups by hatching time and their body weights and body measurements were recorded every 2 weeks. The results obtained were as follows: 1. The body weight at 4,6 and 8 weeks of age, and the length of keel and shank were decreased as hatching times were delayed. Correlation coefficient between hatching tine and body weights or body measurements was negative. 2. Chickens from strain D were hatched 7.4 hours later in male and 7.2 hours in female than chickens from strain C and the growth rate of strain C was superior to that of. strain D.

• Journal of Animal Science and Technology
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• v.46 no.6
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• pp.917-924
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• 2004

Using PCR-RFLP haplotyping for the mitochondrial DNA(mtDNA) fragment containing the NADH dehydrogenase 2 gene(ND2) and three tRNA genes(tRNA-Met, tRNA-Trp and tRNA-Ala), we characterized the genetic diversity of five pig breeds including Jeju native pigs. mtDNA polymorphisms showing distinct cleavage patterns were found in the pig breeds. Two digestion patterns were detected when HaeIII- and Hinfl-RFLP, and four in the Tsp5091-RFLP analyses. Combining the three restriction enzyme digestion patterns found in five different pig breeds, four mtDNA haplotypes were observed and the haplotype frequencies were significantly different by the pig breeds. A monomorphic haplotype, mtWB, was observed in both Korean wild boars and Large White pigs. Both Duroc and Landrace pigs contained two haplotypes suggesting their multiple maternal lineages. Jeju native pig has two haplotypes(mtJN and mtJD). Of these, mtJN is identified as a Jeju native pig specific haplotype. This study suggested that more than two progenitor populations have been taken part in the domestication process of the Jeju native pig population, and/or probably subsequent crossing with other pig breeds from near east Asia. Unlike with our prediction, there was no direct evidence under molecular levels on the maternal introgression of Korean wild boar in the domestication of Jeju native pigs. In conclusion, specificity of mtDNA haplotypes related to pig breeds win be useful for identifying the maternal lineage as wen as constructing the genealogical pedigree in pigs.

• Korean Journal of Veterinary Service
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• v.21 no.2
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• pp.133-139
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• 1998

Serum samples collected from 30 breeders and their progeny 30 chicks. The antibodies against infectious bronchitis(IB), infectious bursal disease (IBD) and Newcastle disease(ND) viruses were detected by ELISA using commercial ELISA kit. The breeders were vaccinated against IB, IBD and ND viruses according to general vaccination program. Geometric mean titers(GMT) of ELISA were monitored from 1-day old to 17-day old chicks and compared with breeder chickens. The GMT of ELISA to IB, IBD and ND were declined half level of the breeder antibody titer at 6-, 8- and 7-day old. And, the GMT of ELISA to IB, IBD and ND were declined than that of protective titer at 6-, 1-, and 4-day old. Thereafter, the GMT of ELISA was declined and disappeared according to ages of chicks. Taken together, this study led to conclusion that time-course of maternal antibody titers of chicks from vaccinated breeders, and this is very important data for vaccination to chicks.

• Journal of Korea Foundry Society
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• v.20 no.6
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• pp.368-376
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• 2000

Rheology forming technology has been accepted as a new method for fabricating near net shaped products with lightweight aluminum alloys. The rheology forming process consists of reheating process of billet, billet handling, filling into the die cavity and solidification of rheology formed part. The rheology forming experiments are performed with two different die temperatures ($T_d$ = $200^{\circ}C$, $300^{\circ}C$) and orifice gate type. The filling behavior and various defects of Al-Si materials with wear resistance (A357, A390 and ALTHIX 86S) fabricated in rheology forming process are evaluated in terms of alloying elements and surface non-uniformity. Finally, the methods to obtain the rheology formed products with high quality are described by solutions for avoiding the surface and internal defects.

• KOREAN POULTRY JOURNAL
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• v.33 no.10 s.384
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• pp.116-118
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• 2001

선천 면역(Maternal immunity)은 모체에서 유래된 lgG class의 항체(모체이행항체)에 의한 면역이다. 이와 같은 면역은 주로 체액성 면역(혈중항체)과 관계 있으며, 국소면역 또는 세포면역은 관여하지 않는다. 일반적으로 1일령 병아리의 항체가는 모계군의 혈청역가 보다 약간 낮게 나타난다. 부화 후 처음 4일간은 난황으로부터 흡수를 함으로써 혈중 항체가가 떨어지지 않고 비슷하게 유지되다가 그 이후 항체가는 차츰 감소하게 된다. 항체가가 감소하는 수준은 닭의 종류에 따라 다른데, 이것은 생리대사와 성장에 좌우되기 때문이다 일반적으로 항체가가 반으로 감소하기까지의 기간(반감기)은 육계의 경우 3일에서 3.5일, 종계의 경우 4.5일, 산란계의 경우 5.5일로 나타난다. 1일령 때의 항체 역가 수준, 닭의 종류, 항체가를 측정하는 혈청검사의 방법 등에 따라 모체이행 감소 수준이 다르긴 하지만 보통 수주 이내에 완전히 소실되게 된다.

• Proceedings of the KWS Conference
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• 2005.06a
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• pp.229-231
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• 2005

Friction surfacing of STS304 consumable rod on S45C substrate was investigated by microstructural observation and mechanical tests. STS304 layer formed a strongly-bonded thick layer under a wide range of surfacing conditions. The hardness distribution showed the peak value in the boundry layer, while the highest coating efficiency obtained in the condition of 1000rpm-2.5mm/sec-2.5mm/sec. As the consumable rotation rate and the traveling rate increased, the coating efficiency tended to decrease. On the other hand, as the feeding rate increased, the coating efficiency appeared to be increased.