• Title/Summary/Keyword: Genetic effects

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Derivative Evaluation and Conditional Random Selection for Accelerating Genetic Algorithms

  • Jung, Sung-Hoon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.5 no.1
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    • pp.21-28
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    • 2005
  • This paper proposes a new method for accelerating the search speed of genetic algorithms by taking derivative evaluation and conditional random selection into account in their evolution process. Derivative evaluation makes genetic algorithms focus on the individuals whose fitness is rapidly increased. This accelerates the search speed of genetic algorithms by enhancing exploitation like steepest descent methods but also increases the possibility of a premature convergence that means most individuals after a few generations approach to local optima. On the other hand, derivative evaluation under a premature convergence helps genetic algorithms escape the local optima by enhancing exploration. If GAs fall into a premature convergence, random selection is used in order to help escaping local optimum, but its effects are not large. We experimented our method with one combinatorial problem and five complex function optimization problems. Experimental results showed that our method was superior to the simple genetic algorithm especially when the search space is large.

Influence of Inbreeding Depression on Genetic (Co)Variance and Sire-by-Year Interaction Variance Estimates for Weaning Weight Direct-Maternal Genetic Evaluation

  • Lee, C.;Pollak, E.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.10 no.5
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    • pp.510-513
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    • 1997
  • This study examined the effects of ignoring inbreeding depression on (co)variance components for weaning weight through the use of Monte Carlo simulation. Weaning weight is of particular interest as a trait for which additive direct and maternal genetic components exist and there then is the potential for a direct-maternal genetic covariance. Ignoring inbreeding depression in the analytical model (.8 kg reduction of phenotypic value per 1% inbreeding) led to biased estimates of all genetic (co) variance components, all estimates being larger than the true values of the parameters. In particular, a negative bias in the direct-maternal genetic covariance was observed in analyses that ignored inbreeding depression. A small spurious sire-by-year interaction variance was also observed.

Heritability and Genetic Gains for Height Growth in 20-year-Old Korean White Pine in Korea

  • Shin, Man-Yong;Park, Hyung-Soon;Cho, Yoon-Jin;Chung, Dong-Jun
    • Korean Journal of Plant Resources
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    • v.19 no.6
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    • pp.677-679
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    • 2006
  • The objectives of this study were to examine the genetic variation of 20-year-old tree height and to estimate heritabilities and genetic gains of Korean white pine. Analysis of variance showed that families and family x block interaction had the significant (p=0.01) effects on tree height. However, family variation appears to be much greater than the variation due to family x block interaction. Individual tree heritability was higher ($h_I^2=0.73$) than family heritability, ($h_F^2=0.83$) therefore, combined selection showed the largest genetic gain (17.76%) in a given equal intensity of selection.

Recent progress in using Drosophila as a platform for human genetic disease research

  • Wan Hee Yoon
    • Journal of Genetic Medicine
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    • v.20 no.2
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    • pp.39-45
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    • 2023
  • As advanced sequencing technologies continue to uncover an increasing number of variants in genes associated with human genetic diseases, there is a growing demand for systematic approaches to assess the impact of these variants on human development, health, and disease. While in silico analyses have provided valuable insights, it is essential to complement these findings with model organism studies to determine the functional consequences of genetic variants in vivo. Drosophila melanogaster is an excellent genetic model for such functional studies due to its efficient genetic technologies, high gene conservation with humans, accessibility to mutant fly resources, short life cycles, and cost-effectiveness. The traditional GAL4-UAS system, allowing precise control of gene expression through binary regulation, is frequently employed to assess the effects of monoallelic variants. Recombinase medicated cassette exchange or CRISPR-Cas9-mediated GAL4 insertion within coding introns or substitution of gene body with Kozak-Gal4 result in the loss-of-function of the target gene. This GAL4 insertion strategy also enables the expression of reference complementary DNA (cDNA) or cDNA carrying genetic variants under the control of endogenous regulatory cis elements. Furthermore, the CRISPR-Cas9-directed tissue-specific knockout and cDNA rescue system provides the flexibility to investigate candidate variants in a tissue-specific and/or developmental-timing dependent manner. In this review, we will delve into the diverse genetic techniques available in Drosophila and their applications in diagnosing and studying numerous undiagnosed diseases over the past decade.

A genome-wide association study of social genetic effects in Landrace pigs

  • Hong, Joon Ki;Jeong, Yong Dae;Cho, Eun Seok;Choi, Tae Jeong;Kim, Yong Min;Cho, Kyu Ho;Lee, Jae Bong;Lim, Hyun Tae;Lee, Deuk Hwan
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.6
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    • pp.784-790
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    • 2018
  • Objective: The genetic effects of an individual on the phenotypes of its social partners, such as its pen mates, are known as social genetic effects. This study aims to identify the candidate genes for social (pen-mates') average daily gain (ADG) in pigs by using the genome-wide association approach. Methods: Social ADG (sADG) was the average ADG of unrelated pen-mates (strangers). We used the phenotype data (16,802 records) after correcting for batch (week), sex, pen, number of strangers (1 to 7 pigs) in the pen, full-sib rate (0% to 80%) within pen, and age at the end of the test. A total of 1,041 pigs from Landrace breeds were genotyped using the Illumina PorcineSNP60 v2 BeadChip panel, which comprised 61,565 single nucleotide polymorphism (SNP) markers. After quality control, 909 individuals and 39,837 markers remained for sADG in genome-wide association study. Results: We detected five new SNPs, all on chromosome 6, which have not been associated with social ADG or other growth traits to date. One SNP was inside the prostaglandin $F2{\alpha}$ receptor (PTGFR) gene, another SNP was located 22 kb upstream of gene interferon-induced protein 44 (IFI44), and the last three SNPs were between 161 kb and 191 kb upstream of the EGF latrophilin and seven transmembrane domain-containing protein 1 (ELTD1) gene. PTGFR, IFI44, and ELTD1 were never associated with social interaction and social genetic effects in any of the previous studies. Conclusion: The identification of several genomic regions, and candidate genes associated with social genetic effects reported here, could contribute to a better understanding of the genetic basis of interaction traits for ADG. In conclusion, we suggest that the PTGFR, IFI44, and ELTD1 may be used as a molecular marker for sADG, although their functional effect was not defined yet. Thus, it will be of interest to execute association studies in those genes.

Genetic and Non-genetic Factors Affecting Mortality in Lori-Bakhtiari Lambs

  • Vatankhah, M.;Talebi, M.A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.4
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    • pp.459-464
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    • 2009
  • Data and pedigree information for Lori-Bakhtiari sheep used in this study were 6,239 records of lamb mortality from 246 sires and 1,721 dams, collected from 1989 through 2007 from a Lori-Bakhtiari flock at Shooli station in Shahrekord. The traits investigated were cumulative lamb mortality from birth up to 7 days, up to 14 days, up to 21 days, and up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 months of age. The models included fixed factors that had significant effects and random direct genetic, maternal genetic and maternal permanent environmental effects. Variance components were estimated using the restricted maximum likelihood procedure applying three animal models with and without maternal and common environmental effects. The overall mean of cumulative lamb mortality rate was 22.95% from birth to 1 year of age, while the overall mortality rate up to 3 and from 3 to 6 months of age was 6.14% and 12.76%, respectively. The mortality rate after 6 months of age declined as the lambs grew older. The age of dam had no important effect on lamb mortality. The type of birth was more important during the preweaning period than at later ages, and lamb mortality rate was higher in twins. The year of birth, month of birth and sex of lamb significantly (p${\leq}$0.01) affected the cumulative lamb mortality rate at all ages. The least square mean of mortality during the final one-third of the lambing period was higher than the first and middle onethird of the lambing period. Male lambs were found to be at a higher risk of mortality than females. Birth weight of the lamb had a highly significant (p${\leq}$0.01) effect on lamb mortality at all ages as a quadratic regression. Direct and maternal heritability estimates of lamb mortality ranged from 0.01 to 0.13 and 0.01 to 0.05, respectively. Direct heritability increased with age of lamb, while maternal effects (genetic and common environmental) were important in the preweaning period. These results indicate that lamb mortality can be reduced first through farm management practices and secondly by genetic selection. Both animal and maternal effects should be considered in breeding programmes for reducing lamb mortality at preweaning.

CYTOGENETIC EFFECTS OF ORGANOPHOSPHATE PESTICIDES ON GOAT LYMPHOCYTES IN CULTURE

  • Gupta, S.C.;Sahal, R.;Gupta, N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.9 no.4
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    • pp.449-454
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    • 1996
  • Cytogenetic effects of malathion and parathion, the organophosphorus pesticides were studied on goat lymphocytes in culture. The mitotic indices (% of blast cells + cells at metaphase) of goat lymphocytes showed corresponding decrease with the increase in dose of pesticides. Malathion had significant effect only at $150{\mu}g/ml$ or higher dosages while, parathion caused antimitotic effects even at the lowest dose ($5{\mu}g/ml$) tested. The clastogenic effects of malathion were significant ($p{\leq}0.05$) at $100{\mu}g/ml$. In higher doses, the effects were highly significant ($p{\leq}0.01$). The frequency of metaphase plates with chromosomal abnormalities were highest (22.0%) at $200{\mu}g/ml$. The incidences of chromosomal abnormalities were significant ($p{\leq}0.05$) in parathion treated series even at $5{\mu}g/ml$ dose level. At $10{\mu}g/ml$ or higher dose levels the difference between treatment groups and controls were more pronounced ($p{\leq}0.01$). Various types of chromosomal abnormalities were encountered in goat lymphocytes treated by malathion and parathion. However, the incidence of gaps, breaks, acentric fragments, dicentric chromosomes were higher than other types of structural and numerical abnormalities.

Photoaging protective effects of BIOGF1K, a compound-K-rich fraction prepared from Panax ginseng

  • Hong, Yo Han;Kim, Donghyun;Nam, Gibaeg;Yoo, Sulgi;Han, Sang Yun;Jeong, Seong-Gu;Kim, Eunji;Jeong, Deok;Yoon, Keejung;Kim, Sunggyu;Park, Junseong;Cho, Jae Youl
    • Journal of Ginseng Research
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    • v.42 no.1
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    • pp.81-89
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    • 2018
  • Background: BIOGF1K, a compound-K-rich fraction, has been shown to display anti-inflammatory activity. Although Panax ginseng is widely used for the prevention of photoaging events induced by UVB irradiation, the effect of BIOGF1K on photoaging has not yet been examined. In this study, we investigated the effects of BIOGF1K on UVB-induced photoaging events. Methods: We analyzed the ability of BIOGF1K to prevent UVB-induced apoptosis, enhance matrix metalloproteinase (MMP) expression, upregulate anti-inflammatory activity, reduce sirtuin 1 expression, and melanin production using reverse transcription-polymerase chain reaction, melanin content assay, tyrosinase assay, and flow cytometry. We also evaluated the effects of BIOGF1K on the activator protein-1 signaling pathway, which plays an important role in photoaging, by immunoblot analysis and luciferase reporter gene assays. Results: Treatment of UVB-irradiated NIH3T3 fibroblasts with BIOGF1K prevented UVB-induced cell death, inhibited apoptosis, suppressed morphological changes, reduced melanin secretion, restored the levels of type I procollagen and sirtuin 1, and prevented mRNA upregulation of MMP-1, MMP-2, and cyclo-oxygenase-2; these effects all occurred in a dose-dependent manner. In addition, BIOGF1K markedly reduced activator-protein-1-mediated luciferase activity and decreased the activity of mitogen-activated protein kinases (extracellular response kinase, p38, and C-Jun N-terminal kinase). Conclusion: Our results strongly suggest that BIOGF1K has anti-photoaging activity and that BIOGF1K could be used in anti-aging cosmeceutical preparations.

The Effects of Genetic Groups, Nutrition, Finishing Systems and Gender of Brazilian Cattle on Carcass Characteristics and Beef Composition and Appearance: A Review

  • Pizzi Rotta, Polyana;do Prado, Rodolpho Martin;do Prado, Ivanor Nunes;Valero, Maribel Velandia;Visentainer, Jesui Vergilio;Silva, Roberio Rodrigues
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.12
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    • pp.1718-1734
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    • 2009
  • The aim of this review is to address some characteristics that influence meat quality. Genetic groups, nutrition, finishing systems and gender are the major factors that change carcass characteristics, chemical composition and fatty acid profile. Genetic groups that have zebu genes in their composition show higher hot carcass dressing than genetic groups without zebu genes. Genetic groups that have European breeds in their composition have higher marbling scores. On the other hand, genetic groups that have zebu breeds show low marbling scores. Bulls finished in feedlots present higher final weight than steers, cull cows and heifers. Fat thickness is one of the principal parameters that are affected by different gender. Cull cows (4.72 mm) and heifers (4.00 mm) present higher values than bulls (1.75 mm) and steers (2.81 mm). The major effects observed by different systems of termination are fat thickness and marbling. Crude protein presents variation due to nutrition. Nutrition influences variation of fatty acid profile. Genetic groups also influence fatty acid profile. Genetic groups that have zebu genes in their composition show high percentage of PUFA. The major class of fatty acids that is changed with nutrition is PUFA. The better ratios of PUFA/SFA and n-6/n-3 are found in Longissimus muscle of animals finished in pasture systems.