• Journal of Animal Science and Technology
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• v.57 no.5
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• pp.19.1-19.6
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• 2015

The objective of this study was to estimate variance components and genetic parameters for growth curve parameters in Guilan sheep. Studied traits were parameters of Brody growth model which included A (asymptotic mature weight), B (initial animal weight) and K (maturation rate). The data set and pedigree information used in this study were obtained from the Agricultural Organization of Guilan province (Rasht, Iran) and comprised 8647 growth curve records of lambs from birth to 240 days of age during 1994 to 2014. Marginal posterior distributions of parameters and variance components were estimated using TM program. The Gibbs sampler was run 300000 rounds and the first 60000 rounds were discarded as a burn-in period. Posterior mean estimates of direct heritabilities for A, B and K were 0.39, 0.23 and 0.039, respectively. Estimates of direct genetic correlation between growth curve parameters were 0.57, 0.03 and -0.01 between A-B, A-K and B-K, respectively. Estimates of direct genetic trends for A, B and K were positive and their corresponding values were $0.014{\pm}0.003$ (P < 0.001), $0.0012{\pm}0.0009$ (P > 0.05) and $0.000002{\pm}0.0001$ (P > 0.05), respectively. Residual correlations between growth curve parameters varied form -0.52 (between A-K) to 0.48 (between A-B). Also, phenotypic correlations between growth curve parameters varied form -0.49 (between A-K) to 0.47 (between A-B). The results of this study indicated that improvement of growth curve parameters of Guilan sheep seems feasible in selection programs. It is worthwhile to develop a selection strategy to obtain an appropriate shape of growth curve through changing genetically the parameters of growth model.

• The Korean Journal of Mycology
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• v.29 no.2
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• pp.99-103
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• 2001

Genetic variation of the wild strains of Lentinula edodes[(Berk.)Pegler] in three regions of Korea was investigated by analyzing random amplified polymorphic DNA (RAPD) markers. A total of 32 strains of L. edodes were collected from Mt. Kyebang (10 strains), Mt. Odae (11), and Mt. Jiri (11), respectively. The genomic DNA was amplified by polymerase chain reaction (PCR) using an arbitrary 10-mer primer. A total of 170 amplified fragments were observed, of which 161 fragments were polymorphic. The results of cluster analysis, performed on the basis of the presence or absence of amplified fragments of the same size, revealed that strains collected from both Mt. Kyebang and Mt. Odae in a single group. AMOVA analysis revealed that genetic variations between sites amounted to 12.5%, while 87.1% of total variations was explained by variations among strains within sites. Relatively high genetic relationships among the strains of Mt. Kyebang and Mt. Odae, which were high variance within populations. Whereas, all the strains of Mt. Jiri, which were low variance among populations from both Mt. Kyebang and Mt. Odae, which resulted in genetic isolation of the strains in Mt. Jiri.

• Journal of Veterinary Science
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• v.22 no.4
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• pp.50.1-50.10
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• 2021

Background: Bovine papillomatosis is a type of proliferative tumor disease of skin and mucosae caused by bovine papillomavirus (BPV). As a transboundary and emerging disease in cattle, it poses a potential threat to the dairy industry. Objectives: The aim of this study is to detect and clarify the genetic diversity of BPV circulating in dairy cows in Xinjiang, China. Methods: 122 papilloma skin lesions from 8 intensive dairy farms located in different regions of Xinjiang, China were detected by polymerase chain reaction. The genetic evolution relationships of various types of BPVs were analyzed by examining this phylogenetic tree. Results: Ten genotypes of BPV (BPV1, BPV2, BPV3, BPV6, BPV7, BPV8, BPV10, BPV11, BPV13, and BPV14) were detected and identified in dairy cows. These were the first reported detections of BPV13 and BPV14 in Xinjiang, Mixed infections were detected, and there were geographical differences in the distribution of the BPV genotypes. Notably, the BPV infection rate among young cattle (< 1-year-old) developed from the same supply of frozen sperm was higher than that of the other young cows naturally raised under the same environmental conditions. Conclusions: Genotyping based on the L1 gene of BPV showed that BPVs circulating in Xinjiang China displayed substantial genetic diversity. This study provided valuable data at the molecular epidemiology level, which is conducive to developing deep insights into the genetic diversity and pathogenic characteristics of BPVs in dairy cows.

• Animal Bioscience
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• v.34 no.9
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• pp.1460-1465
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• 2021

Objective: The study aimed to evaluate the diversity of donkey populations by comparing with the diversity of Thoroughbred and Jeju Halla horses; identified breeding backgrounds can contribute to management and conservation of donkeys in South Korea. Methods: A total of 100 horse (50 Thoroughbreds and 50 Jeju Halla horses) and 79 donkeys samples were genotyped with 15 microsatellite markers (AHT4, AHT5, ASB2, ASB17, ASB23, CA425, HMS1, HMS2, HMS3, HMS6, HMS7, HTG4, HTG10, LEX3, and VHL20), to identify genetic diversity and relationships among horses and donkeys. Results: The observed number of alleles per locus ranged from 1 (ASB17, HMS1) to 14 (AHT5), with a mean value of 4.87, 8.00, and 5.87 in Thoroughbreds, Jeju Halla horses, and donkeys, respectively. Of the 15 markers, AHT4, AHT5, ASB23, CA425, HMS2, HMS3, HTG4, HTG10, and LEX3 loci had relatively high polymorphism information content (PIC) values (PIC>0.5) in these three populations. Mean levels of genetic variation were H_E = 0.6721 and H_O = 0.6600 in Thoroughbreds, H_E = 0.7898 and H_O = 0.7100 in Jeju Halla horses, and H_E = 0.5635 and H_O = 0.4861 in donkeys. Of the 15 loci in donkeys, three loci had negative inbreeding coefficients (FIS), with a moderate mean FIS (0.138). The FIS estimate for the HTG4 marker was highest (0.531) and HMS6 marker was lowest (-0.001). The total probability of exclusion value of 15 microsatellite loci was 0.9996 in donkeys. Conclusion: Genetic cluster analysis showed that the genetic relationship among 79 donkeys was generally consistent with pedigree records. Among the three breeds, donkeys and Thoroughbred horses formed clearly different groups, but the group of Jeju Halla horses overlapped with that of Thoroughbred horses, suggesting that the loci would be suitable for donkey parentage testing. Therefore, the results of this study are a valid tool for genetic study and conservation of donkeys.

• Journal of Life Science
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• v.25 no.11
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• pp.1204-1213
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• 2015

A comprehensive analysis of the population structure of the sandfish (Arctoscopus japonicas), the most abundant fishery resource in the East Sea of Korea, has not been carried out, despite its importance in Korea. The present study examined the genetic diversity and differences between five populations (two Japanese and three Korean populations) of A. japonicas captured in the East Sea using both the 401 bp sequence of mitochondrial DNA (mtDNA, cytochrome b) and five microsatellite DNA (msDNA) markers. The results of the analysis using the Cyt b sequence revealed 27 haplotypes. Based on msDNA variations, the estimated expected heterozygosity (H_E) in each population ranged from 0.68 (Gampo, Korea) to 0.7765 (Erimo, Japan). Pairwise F_ST and AMOVA tests using both the Cyt b sequence and msDNA data pointed to significant differences between the Korean and Japanese populations (mtDNA; F_ST=0.2648, p<0.05, msDNA; F_ST=0.0814, p<0.05). These results were similar to the results of UPGMA, PCA, and structure analysis. In these analyses, the five populations were assigned to two groups (Korean populations and Japanese populations). These results shed light on the genetic diversity and relationships of A. japonicas and contribute to research on the evaluation, conservation, and utilization of Korean A. japonicas as genetic resources.

• Korean Journal of Environmental Biology
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• v.17 no.3
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• pp.321-330
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• 1999

Nematodes were isolated using silkwom trap through the investigation of 100 soil samples from various biotopes in Korea. The 30 nematode strains from soil and dead insects by the pathogenicity aganinst silkworms (Bombyx mori mori) and insect pests of Calliphora vomitoria, Pseufazetia separata, Palomena angulosa, and Melolontha incana. Mortailty of the silkworm larvae and pupae were as high as 100% by nematode infection, those of insect of pests were varied from 20 to 100%. The 30 strains of entemopathogenic nematodes were classified into five groups of Rhabditidae, Diplogatroidae, Heterorhabitidae, Steinernematidae, and Tylenchida by morphological criteria. The genetic relationships among the 30 nematode strains were analyzed by various RAPD bands with twenty primers. The 30 nematode strains were classified into six major subgroups on the basis of the genetic similarity coefficient of 0.853. The grouping by RAPD was agree with those of morphological taxa in discrimination of the higher group, however, was not completely agree in the subgroup. The family Steinernematidae belong to Rhabditida was clarified as closer to the Tylenchida, rather than the other Rhabditida of Heterorhabitidae, Rhabditidae, and Diplogatroidae in genetic distance valule. From the result of the morphological classification and RAPD of the genomic DNA showed that genetic relationship analysis furnish infurmation on phylogenetic classification and relationships of entomopathogenic nematodes. The application of genetic similarity will overcome the limitation of taxonomy and classification of morphologically simple nematode. Several primers were confirmed those utility of identification for individual nematode strains, the methods of molecular genetics secured the simplicity, rapidity and accuracy on the selection of entomopathogenic nematodes.

• Korean Journal of Environmental Biology
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• v.26 no.2
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• pp.66-75
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• 2008

The level of genetic diversity and genetic relationships among Korean ring-necked pheasant (Phasianus colchicus karpowi) habitat and subspecies have been investigated based on Inter Simple Sequence Repeat (ISSR) markers. Wild and domesticated Korean ring-necked pheasant, hybrids between domesticated Korean ring-necked and foreign subspecies, and four foreign subspecies; Chinese ring-necked (P. c. torquatus), Melanistic mutant (P. c. mut. tenebrosus), XL White (P. c. mut) and Southern green (P. c. versicolor) were used for comparison. On the basis of the results of AMOV A, 94.08% of genetic diversity in Korean ring-necked was allocated among individuals within habitat differences. Estimate of $\Phi$st, which represents the degree of genetic differentiation among habitats was 5.9%. Based on the dendrogram reconstructed by UPGMA, Yangpyung habitat of the eight habitats turned out to be distinct from others habitat. Interestingly, domesticated Korean ring-necked and hybrid mixture showed closer genetic relationship with four foreign subspecies than Korean ring-necked. As a consequence of AMOVA, 96.63% of genetic diversity in four foreign subspecies was allocated among individuals within subspecies. Estimate of $\Phi$st representing the degree of genetic differentiation among subspecies was 3.4%, which was lower than that among habitats of Korean ring-necked. The lower level of genetic difference among four foreign subspecies showed that these subspecies were genetically closer even though they were morphologically classified into four different subspecies. When seven habitats of Korean ring-necked pheasant and four foreign subspecies were divided into Korean and Foreign Pheasant Groups, respectively, more than 17% of genetic diversity was allocated between groups (about 4% among habitats/subspecies within groups). This observation implied that Korean ring-necked pheasant is genetically quite different from four foreign subspecies. On the basis of cluster analysis, three foreign subspecies (Chinese ring-necked pheasant, Melanistic mutant pheasant, and XL White pheasant) formed a distinct group with domesticated Korean ring-necked pheasant and hybrid mixture at 98% confidence interval.

• Journal of Animal Science and Technology
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• v.52 no.5
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• pp.357-366
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• 2010

The emergence of next-generation sequencing technologies has lead to application of new computational and statistical methodologies that allow incorporating genetic information from entire genomes of many individuals composing the population. For example, using single-nucleotide polymorphisms (SNP) obtained from whole genome amplification platforms such as the Ilummina BovineSNP50 chip, many researchers are actively engaged in the genetic evaluation of cattle livestock using whole genome relationship analyses. In this study, we estimated the genomic relationship matrix (GRM) and compared it with one computed using a pedigree relationship matrix (PRM) using a population of Hanwoo. This project is a preliminary study that will eventually include future work on genomic selection and prediction. Data used in this study were obtained from 187 blood samples consisting of the progeny of 20 young bulls collected after parentage testing from the Hanwoo improvement center, National Agriculture Cooperative Federation as well as 103 blood samples from the progeny of 12 proven bulls collected from farms around the Kyong-buk area in South Korea. The data set was divided into two cases for analysis. In the first case missing genotypes were included. In the second case missing genotypes were excluded. The effect of missing genotypes on the accuracy of genomic relationship estimation was investigated. Estimation of relationships using genomic information was also carried out chromosome by chromosome for whole genomic SNP markers based on the regression method using allele frequencies across loci. The average correlation coefficient and standard deviation between relationships using pedigree information and chromosomal genomic information using data which was verified using a parentage test andeliminated missing genotypes was $0.81{\pm}0.04$ and their correlation coefficient when using whole genomic information was 0.98, which was higher. Variation in relationships between non-inbred half sibs was $0.22{\pm}0.17$ on chromosomal and $0.22{\pm}0.04$ on whole genomic SNP markers. The variations were larger and unusual values were observed when non-parentage test data were included. So, relationship matrix by genomic information can be useful for genetic evaluation of animal breeding.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1521-1525
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• 2014

This study investigated heritability for bovine growth estimated with genomewide single nucleotide polymorphism (SNP) information obtained from a DNA microarray chip. Three hundred sixty seven Korean cattle were genotyped with the Illumina BovineSNP50 BeadChip, and 39,112 SNPs of 364 animals filtered by quality assurance were analyzed to estimate heritability of body weights at 6, 9, 12, 15, 18, 21, and 24 months of age. Restricted maximum likelihood estimate of heritability was obtained using covariance structure of genomic relationships among animals in a mixed model framework. Heritability estimates ranged from 0.58 to 0.76 for body weights at different ages. The heritability estimates using genomic information in this study were larger than those which had been estimated previously using pedigree information. The results revealed a trend that the heritability for body weight increased at a younger age (6 months). This suggests an early genetic evaluation for bovine growth using genomic information to increase genetic merits of animals.

• Korean Journal of Biological Psychiatry
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• v.4 no.2
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• pp.188-193
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• 1997

Along with psychosocial factors of suicide, biological backgrounds of suicide are explored by extensive works mostly on biological markers, neurobiological models, genetic bases, and relationships with aggression and violence. The biology of suicide confers on neurotransmitters in central nervous system exploring metabolites, receptor binding affinities, neuroendocrine challenge tests in brain, cerebrospinal fluid, blood and etc. The major concerns with suicide are focused mainly on serotonin system : low CSF 5-HIAA concentration, higher $5-HT_2$ receptor binding, and blunt prolactin response to fenfluramine. Postmortem study, in vivo study, genetic contributions, and some other issues such as suicidal methods, serum cholesterol, alcohol, and selective serotonin reuptake inhibitors are reviewed and discussed.