• Asian-Australasian Journal of Animal Sciences
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• 제20권1호
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• pp.19-24
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• 2007

Covariance components and genetic parameters of weekly live body weight from hatching to six weeks of age and age of sexual maturation were estimated in a laying type Japanese quail line. The univariate and bivariate animal model analysis included hatching group and sex as fixed effects. Each trait was analysed with animal as random effect to fit the additive direct effect. Additional random effects incorporated in the models were changed according to the trait examined. The best model for a trait was chosen based on a likelihood ratio test, comparing the models with and without maternal additive genetic and maternal permanent environmental effects. Heritability estimates of live-weight at hatch and one to six weeks of age with their standard errors were 0.22${\pm}$0.088, 0.39${\pm}$0.099, 0.31${\pm}$0.086, 0.38${\pm}$0.056, 0.46${\pm}$0.055, 0.50${\pm}$0.059, and 0.56${\pm}$0.062, respectively. Direct heritability value of age of sexual maturation was moderate (0.24${\pm}$0.055). The variances due to permanent environmental effect of dam after one week of age and maternal genetic effect after two weeks of age were not important sources of variation. The correlations between direct and maternal genetic effects were negative and ranged from high to moderate values (-0.21 to -0.83). Among the weekly live weights, genetic correlations were generally high between not only successive but also early and late weightings. It suggests that selection for final weight may be based on early weight records. Genetic correlations between age of sexual maturation and live weights were low, favourable but had high standard errors. These results indicate that selection for high weight will potentially result in lower age of sexual maturation only with accurate determination of breeding values.

• Animal Bioscience
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• 제37권4호
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• pp.576-590
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• 2024

Objective: The objective of this study was to identify genes associated with 305-day milk yield (MY) and fat yield (FY) that also influence the adaptability of the Thai multibreed dairy cattle population to tropical conditions. Methods: A total of 75,776 imputed and actual single nucleotide polymorphisms (SNPs) from 2,661 animals were used to identify genomic regions associated with MY and FY using the single-step genomic best linear unbiased predictions. Fixed effects included herd-year-season, breed regression, heterosis regression and calving age regression effects. Random effects were animal additive genetic and residual. Individual SNPs with a p-value smaller than 0.05 were selected for gene mapping, function analysis, and quantitative trait loci (QTL) annotation analysis. Results: A substantial number of QTLs associated with MY (9,334) and FY (8,977) were identified by integrating SNP genotypes and QTL annotations. Notably, we discovered 17 annotated QTLs within the health and exterior QTL classes, corresponding to nine unique genes. Among these genes, Rho GTPase activating protein 15 (ARHGAP15) and catenin alpha 2 (CTNNA2) have previously been linked to physiological traits associated with tropical adaptation in various cattle breeds. Interestingly, these two genes also showed signs of positive selection, indicating their potential role in conferring tolerance to trypanosomiasis, a prevalent tropical disease. Conclusion: Our findings provide valuable insights into the genetic basis of MY and FY in the Thai multibreed dairy cattle population, shedding light on the underlying mechanisms of tropical adaptation. The identified genes represent promising targets for future breeding strategies aimed at improving milk and fat production while ensuring resilience to tropical challenges. This study significantly contributes to our understanding of the genetic factors influencing milk production and adaptability in dairy cattle, facilitating the development of sustainable genetic selection strategies and breeding programs in tropical environments.

• 한국연초학회지
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• 제13권2호
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• pp.59-65
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• 1991

There was no a difference of genetic analysis among methods(means, joint scaling test, 3 Parameter model) . The magnitude of additive effects generally paralleled the magnitude of difference between parental means and appeared to be more independent from non-allelic interaction than did dominance effects, whereas the magnitude of dominance effects were inflated by non-allelic interaction. Additive effects were significant for all characteristics observed and it was a major effects in inheritance of number of leaves. Dominance effects were higher than additive effects for plant height, days to flower, flesh leaf weight per plant, curing rate, total alkaloid and total nitrogen.

• 한국컴퓨터정보학회논문지
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• 제10권6호
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• pp.85-92
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• 2005

본 논문에서는 변형된 돌연변이 연산자를 적용한 대화형 유전자 알고리즘을 사용해서 웹-기반 학습 콘텐츠를 개발하였다. 대화형 유전자 알고리즘은 주로 상호 교환(reciprocal exchange) 돌연변이를 사용한다. 그러나 본 논문에서는 학습자의 학습 효과를 높이기 위해 돌연변이 연산자를 변형하였다. 그리고, 대화형 유전자 알고리즘을 이용한 웹 기반 학습 콘텐츠는 동적인 학습 내용과 실시간 테스트 시스템을 제공한다. 특히 학습자가 자신의 특성과 흥미에 따라 대화형 유전자 알고리즘을 수행하면서 효율적인 학습 환경과 콘텐츠 배열 순서를 선택할 수 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권8호
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• pp.1222-1226
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• 2002

Estimates of genetic correlation between direct and maternal effects for weaning weight of beef cattle are often negative in field data. The biological existence of this genetic antagonism has been the point at issue. Some researchers perceived such negative estimate to be an artifact from poor modeling. Recent studies on sources affecting the genetic correlation estimates are reviewed in this article. They focus on heterogeneity of the correlation by sex, selection bias caused from selective reporting, selection bias caused from splitting data by sex, sire by year interaction variance, and sire misidentification and inbreeding depression as factors contributing sire by year interaction variance. A biological justification of the genetic antagonism is also discussed. It is proposed to include the direct-maternal genetic covariance in the analytical models.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.246.1-246.1
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• 2002

We studied the effects of ursodeoxycholic acid (UDCA) and its synthetic derivatives. HS-l030 and HS-1183. and chenodeoxycholic acid (CDCA) and its synthetic derivatives, HS-1199 and HS-1200. on the human colon adenocarcinoma cell line. HT -29 (p53 mutant type). The effects on cell viability and growth were assessed by MTT assay and cell growth study. While UDCA and CDCA exhibited no significant effect, their novel derivatives inhibited the proliferation of HT-29 cell line in a concentration- and time-dependent manners. (omitted)

• Journal of Ecology and Environment
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• 제40권2호
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• pp.84-88
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• 2016

To understand the effects of habitat characteristics on the genetic diversity of Persicaria thunbergii, three sites of different environmental conditions in a water system were surveyed. Site A was the closest to the source of the water system, and there was a dam between sites A and B. Site C is located on the lowest downstream in the water system. Vegetation survey of four quadrats at each site was performed, and soil samples were collected for physicochemical analysis. Random amplification of polymorphic DNA (RAPD) analysis of ten P. thunbergii individuals at each site was conducted to calculate population genetic diversity and genetic distance among populations. Soil was sterile sand at site A, whereas loamy soil at sites B and C. A pure stand of P. thunbergii appeared at site A, while other species occurred together (such as Humulus japonicus and Phragmites australis) at sites B (Shannon-Wiener index; $H_B=0.309$) and C ($H_C=0.299$). Similar to the species diversity, genetic diversity (Nei's gene diversity; h) within population of site A ($h_A=0.2381$) was relatively lower than sites B ($h_B=0.2761$) and C ($h_C=0.2618$). However, site C was separated from sites A and B in genetic distance rather than the geographical distance (Nei's genetic distance; A~B, 0.0338; B~C, 0.0685; A~C, 0.0833).

• Asian-Australasian Journal of Animal Sciences
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• 제21권10호
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• pp.1395-1403
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• 2008

The objective of the present study was to estimate genetic parameters for economic traits in Markhoz goats. Data collected from 1993 to 2006 by the Markhoz goat Performance Testing Station in Sanandaj, Iran, were analyzed. The traits recorded as body weight performance at birth (BW), weaning (WW), six month (6MW), nine month (9MW), yearling (YW) and yearling fleece weight (YFW) were investigated. Least square analyses were used for estimation of environmental effects. Genetic parameters were estimated with single and multi trait analysis using restricted maximum likelihood (REML) procedures, under animal models. By ignoring or including maternal additive genetic effects and maternal permanent environmental effects, five different models were fitted for each trait. The effects of sex, type of birth, age of dam and year of birth on the all body weights were significant (p<0.01), but had no effects on YFW except year of birth. Age of kids had significant influences on WW and 6MW (p<0.01). A log likelihood ratio test was carried out for choosing the most suitable model for each trait. Total heritability estimates for YFW and growth traits varied from 0.16 for YFW and WW to 0.41 for YW. For all traits, maternal heritability was lower than direct heritability, ranging from 0.06 for BW to 0.01 for 6MW and 9MW. The magnitude of $c^2$ was more substantial for BW than the others, and relative importance was reduced from 0.12 for BW to 0.04 for 9MW. The direct additive genetic correlations estimates were positive and varied from 0.21 between BW-YW to 0.96 between WW-6MW. Direct additive genetic correlations between YFW and body weight traits were positive and ranged from 0.14 between BW-YFW to 0.67 between 6MW-YFW. For all traits, the corresponding estimates for phenotypic correlation were positive and lower than genetic correlations. The maternal additive genetic correlations between various traits were varied and ranged from -0.19 between 9MW-YFW to 0.96 between 6MW-9MW. The estimates of the maternal permanent environmental correlations between various traits were positive and ranged from 0.33 between WW-YFW to 0.93 between WW-6MW. Also, the environmental correlations between various traits ranged from 0.01 between BW-YFW and WW-YFW to 0.70 between 9MW-YW. Estimates of genetic parameters for various traits in this study confirm that selection should be applied on WW for genetic improvement in Markhoz goats.

• Asian-Australasian Journal of Animal Sciences
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• 제14권4호
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• pp.447-454
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• 2001

For determining the relative genetic effects of Duroc (D) and Taoyuan (T) breeds on the economic traits of their hybrids, 72 litters of pigs, from four mating types, namely TT (T♂$\times$T♀), DD (D♂$\times$D♀) and D-T hybrids (TD, T♂$\times$D♀ and DT, D♂$\times$T♀) were used in this study. The various crossbreeding parameters were estimated by comparisons among mating types using linear contrasts of least-square analysis. The results of reproductive traits analysis showed that T breed had contributed superior genetic effects on the total number of piglets at birth (TBN) (p<0.10) and number of live piglets at 21 days (LP21) (p<0.05) to the D-T hybrids. Estimates of maternal genetic effects showed that the T females were superior in TBN (p<0.05), but inferior in average birth weight (ABW) and average litter birth weight (LBW) (p<0.01) to the D females. Direct heterosis effects were significant for LBW, LP21 and LWT21 (p<0.01). Least-squares analysis of other economic traits showed that T breed had relative negative effects on all growth traits, withers height (WH), body type index (BTI), average backfat thickness (ABF), carcass length (LENG), loin eye area (longissimus) (LEARA), and lean percentage (LEAN) of D-T hybrids (p<0.05). Estimates of direct genetic effects showed that the D breed was superior to the T breed in all growth and carcass traits except the average backfat (BF). Estimates of maternal genetic effects showed that average body weight at 180 days (WT180) of progenies from T sows were lighter than from D sows. Progenies from D females had larger and leaner carcass than those from T females. Direct heterosis effects were significant for average daily weight gains from 150 to 180 days ($ADG_{150-180}$) (p<0.05) and for average body weights at 150 (WT150), and 180 days (WT180), average daily weight gains from birth to 150 and 180 days ($ADG_{150}$ and $ADG_{180}$, respectively), WH, body length (BL), ABF, BTI, and LENG (p<0.01). The results showed that D-T hybrids tended to have superior TBN and LP21 than D breed, and to be superior in all growth and most conformation and carcass traits to the T breed.

• Asian-Australasian Journal of Animal Sciences
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• 제25권6호
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• pp.764-771
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• 2012

Direct and maternal genetic heritabilities and their correlations with body weight at 5 stages in the life span of purebred Berkshire pigs, from birth to harvest, were estimated to scrutinize body weight development with the records for 5,088 purebred Berkshire pigs in a Korean farm, using the REML based on an animal model. Body weights were measured at birth (Birth), at weaning (Weaning: mean 22.9 d), at the beginning of a performance test (On: mean 72.7 d), at the end of a performance test (Off: mean 152.4 d), and at harvest (Finish: mean 174.3 d). Ordinary polynomials and Legendre with order 1, 2, and 3 were adopted to adjust body weight with age in the multivariate animal models. Legendre with order 3 fitted best concerning prediction error deviation (PED) and yielded the lowest AIC for multivariate analysis of longitudinal body weights. Direct genetic correlations between body weight at Birth and body weight at Weaning, On, Off, and Finish were 0.48, 0.36, 0.10, and 0.10, respectively. The estimated maternal genetic correlations of body weight at Finish with body weight at Birth, Weaning, On, and Off were 0.39, 0.49, 0.65, and 0.90, respectively. Direct genetic heritabilities progressively increased from birth to harvest and were 0.09, 0.11, 0.20, 0.31, and 0.43 for body weight at Birth, Weaning, On, Off, and Finish, respectively. Maternal genetic heritabilities generally decreased and were 0.26, 0.34, 0.15, 0.10, and 0.10 for body weight at Birth, Weaning, On, Off, and Finish, respectively. As pigs age, maternal genetic effects on growth are reduced and pigs begin to rely more on the expression of their own genes. Although maternal genetic effects on body weight may not be large, they are sustained through life.