• 대한수의학회지
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• 제39권2호
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• pp.311-317
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• 1999

Pathogenic effects of 29 different porcine reproductive and respiratory syndrome(PRRS) virus isolates were investigated in swine tracheal ring(STR) cultures by examining their effects on the ciliary activity of STR. Inhibition of ciliary movement and destruction of the tracheal epithelium were seen between 72 and 96 hours postinoculation(PI). Virus replication was demonstrated by examining viral infectivity of the supernatants from the STR cultures. PRRS virus antigen in macrophages was detected by a streptavidin-biotin complex(ABC) immunoperoxidase method. Of the 29 PRRS virus isolates, 8 isolates were classified into pathogenic, and the remaining 21 isolates were determined as mildly pathogenic or apathogenic viruses. These results suggest that STR examination may be used as a method for predicting pathogenic variability of PRRS virus isolates.

• Restorative Dentistry and Endodontics
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• 제43권3호
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• pp.34.1-34.5
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• 2018

In the previous section, we established a simple linear regression line by finding the slope and intercept using the least square method as: ${\hat{Y}}=30.79+0.71X$. Finding the regression line was a mathematical procedure. After that we need to evaluate the usefulness or effectiveness of the regression line, whether the regression model helps explain the variability of the dependent variable. Also, statistical inference of the regression line is required to make a conclusion at the population level, because practically, we work with a sample, which is a small part of population. Basic assumption of sampling method is simple random sampling.

• Anatomy and Cell Biology
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• 제56권3호
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• pp.367-373
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• 2023

One of the main parameters in the analysis of skeletal remains in forensic anthropological cases is the estimation of age. This study aimed to investigate the correlation between age and the fusion status of the sternal junction. This cross-sectional study was carried out on 184 sterna from 94 females and 90 males obtained from known-age cadavers in the Thai population. By direct observation, the fusion stage of the manubrio-sternal and sterno-xiphoidal junctions was studied and divided into unfused and fused joints. The results showed that a large proportion of the sterna remain unfused throughout adulthood, with fusion observed in both young and old cadavers. Insignificant differences in the rate of fusion, the sexes and ages were observed. None of the sterna under 30 years of age in females and 32 years of age in males showed fusion of the manubrio-sternal and sterno-xiphoidal junctions. Based on the variability of the sternal fusions observed in this study, we highlighted a very limited role of the sternum alone in the estimation of age in the Thai population.

• Asian-Australasian Journal of Animal Sciences
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• 제25권8호
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• pp.1063-1072
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• 2012

Effective population size ($N_e$) is an important measure to understand population structure and genetic variability in animal species. The objective of this study was to estimate $N_e$ in Sapsaree dogs using the information of rate of inbreeding and genomic data that were obtained from pedigree and the Illumina CanineSNP20 (20K) and CanineHD (170K) beadchips, respectively. Three SNP panels, i.e. Sap134 (20K), Sap60 (170K), and Sap183 (the combined panel from the 20K and 170K), were used to genotype 134, 60, and 183 animal samples, respectively. The $N_e$ estimates based on inbreeding rate ranged from 16 to 51 about five to 13 generations ago. With the use of SNP genotypes, two methods were applied for $N_e$ estimation, i.e. pair-wise $r^2$ values using a simple expectation of distance and $r^2$ values under a non-linear regression with respective distances assuming a finite population size. The average pair-wise $N_e$ estimates across generations using the pairs of SNPs that were located within 5 Mb in the Sap134, Sap60, and Sap183 panels, were 1,486, 1,025 and 1,293, respectively. Under the non-linear regression method, the average $N_e$ estimates were 1,601, 528, and 1,129 for the respective panels. Also, the point estimates of past $N_e$ at 5, 20, and 50 generations ago ranged between 64 to 75, 245 to 286, and 573 to 646, respectively, indicating a significant $N_e$ reduction in the last several generations. These results suggest a strong necessity for minimizing inbreeding through the application of genomic selection or other breeding strategies to increase $N_e$, so as to maintain genetic variation and to avoid future bottlenecks in the Sapsaree population.

• Animal cells and systems
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• 제14권1호
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• pp.31-36
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• 2010

The pinewood nematode Bursaphelenchus xylophilus causes pine wilt disease and is a serious economic concern for the forest industry of South Korea. To achieve effective control with limited resources, it is necessary to clarify the transmission routes and mechanisms of dispersal of this organism. Highly polymorphic and easy-to-use molecular markers can be used for investigating this aspect. In this study, we evaluated the usefulness of amplified fragment length polymorphisms (AFLPs) for investigating the genetic variations of B. xylophilus and related individuals from China, Japan, and South Korea. The AFLP patterns obtained in our study were similar to the microsatellite patterns reported in a previous study; our AFLP patterns indicated high genetic variability and cryptic genetic structure, but did not indicate any peculiar geographic structure. Moreover, the genetic distances between individuals suggested that the Korean population was affected to a greater extent by the Chinese population than the Japanese population. Further, the gene flow among the related species appeared to be limited; however, there may be also the possibility of genetic introgression among species. These results confirm the usefulness of AFLPs for understanding the epidemiology of pine wilt disease, thereby contributing to the effective control of this disease.

• Asian-Australasian Journal of Animal Sciences
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• 제16권2호
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• pp.277-281
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• 2003

Amplified fragment length polymorphism (AFLPs) markers were used to investigate the genetic variation in six autochthonous goat populations distributed in the middle and lower Yangtze River valley. The goat populations were Chengdu Grey Goat (CGG), Chuandong White Goat (CWG), Banjiao Goat (BG), Matou Goat (MG), Hui Goat (HG) and Yangtze River Delta White Goat (YRDWG). A total of 180 individuals (30 per population) were analysed using ten selected AFLP primer combinations that produced 78 clear polymorphism loci. The variability at AFLP loci was largely maintained within populations, as indicated by the average genetic similarity, and they were ranged from 0.745 to 0.758 within populations and 0.951 to 0.970 between populations. No breed specific markers were identified. Cluster analysis based on Nei' genetic distance between populations indicated that Chengdu Grey Goat is the most distant population, while CWG and YROWG were the closest populations, followed by BG, HG and MG. Genetic diversity of the goat populations didn' confirm what was expected on the basis of their geographical location, which may reflect undocumented migrations and gene flows and identify an original genetic resource.

• The Plant Pathology Journal
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• 제33권1호
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• pp.34-42
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• 2017

Grapevine rupestris stem pitting-associated virus (GRSPaV) is a worldwide-distributed pathogen in grapevines with a high genetic variability. Our study revealed differences in the complexity of GRSPaV population in a single host. A single-variant GRSPaV infection was detected from the SK30 grapevine plant. On the contrary, SK704 grapevine was infected by three different GRSPaV variants. Variant-specific RT-PCR detection protocols have been developed in this work to study distribution of the three different variants in the same plant during the season. This study showed their randomized distribution in the infected SK704 grapevine plant. Comparative analysis of full-length genome sequences of four Slovak GRSPaV isolates determined in this work and 14 database sequences showed that population of the virus cluster into four major phylogenetic lineages. Moreover, our analyses suggest that genetic recombination along with point mutations could play a significant role in shaping evolutionary history of GRSPaV and contributed to its extant genetic diversification.

• 한국작물학회지
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• 제44권3호
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• pp.256-262
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• 1999

To evaluate the genetic diversity and structure of the South Korean soybean population, 233 landraces collected in various regions of the country were surveyed for 15 allozyme loci and one protein locus. The South Korean population was fixed or nearly fixed at seven of the 16 loci tested. The number of alleles per locus was 2.06 and Nei’s gene diversity was 0.194. These values were lower than the values for the same 16 loci previously reported for the Japanese and Chinese populations. The differences among eight regional groups were not so marked, with only 7.2% of the total variation arising from regional differentiation. Three southern regional groups (Chollabuk-do, Chollanam-do and Kyong-sangnam-do) exhibited a relatively high variability because of frequent occurrence of alleles characteristic of the Japanese population. A marked difference was found in allelic frequencies at the Dial locus between large-seeded landraces and small-seeded ones, suggesting that the latter, which are used mainly for bean sprouts, had been established independently of the former, which are used mostly for soy sauce and cooking with rice. Not only the region but also the usage as food materials should therefore be taken into consideration in designing an efficient collection and preservation method for the Korean soybean landraces.

• Asian-Australasian Journal of Animal Sciences
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• 제19권12호
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• pp.1685-1690
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• 2006

Kenkatha cattle, a draft purpose breed, which can survive in a harsh environment on low quality forage, was explored genetically exploiting FAO-suggested microsatellite markers. The microsatellite genotypes were derived by means of the polymerase chain reaction (PCR) followed by electrophoretic separation in agarose gels. The PCR amplicons were visualized by silver staining. The allelic as well as genotypic frequencies, heterozygosities and gene diversity were estimated using standard techniques. A total of 125 alleles was distinguished by the 21 microsatellite markers investigated. All the microsatellites were highly polymorphic with mean allelic number of 5.95${\pm}$1.9 (ranging from 3-10 per locus). The observed heterozygosity in the population ranged between 0.250 and 0.826 with a mean of 0.540${\pm}$0.171, signifying considerable genetic variation. Bottleneck was examined assuming all three mutation models which showed that the population has not experienced bottleneck in recent past. The population displayed a heterozygote deficit of 21.4%. The study suggests that the breed needs to be conserved by providing purebred animals in the breeding tract.

• Animal cells and systems
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• 제16권6호
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• pp.498-505
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• 2012

This study uses the mitochondrial DNA control region to identify the genetic diversity and population structure of the marbled soles (Pleuronectes yokohamae) that inhabit Jinhae Bay and Yokji Island in the nearby sea and the adjacent waters of Namhae, Hansan Island, and Jaran Bay. Direct sequencing of the PCR products revealed 379 bp sequences with 83 variable nucleotide sites, defining a total of 91 haplotypes. The haplotype diversity was high, ranging from $0.917{\pm}0.031$ to $0.983{\pm}0.008$, and nucleotide diversity ranged from $0.015{\pm}0.008$ to $0.024{\pm}0.012$. In addition, 48 haplotypes (52.7%) were unique. Pairwise $F_{ST}$ values were very low, with the maximum value occurring between PYH (Hansan Island) and PJI (Jinhae Bay) ($F_{ST}$ = 0.011). Therefore, no significant genetic differentiation was evident between any pair of sampling localities.