• Asian-Australasian Journal of Animal Sciences
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• v.10 no.4
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• pp.416-421
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• 1997

The effect of imported young bulls on the genetic progress was examined in the Holstein dairy cattle population in Japan. The effect of the difference of mean genetic merit between imported and domestic young bulls ("genetic difference") was recognized on the genetic progress of the domestic animals in the early stage of selection. On the other hand, the genetic progress of domestic animals were remarkably influenced by the genetic trend of imported young bulls ("genetic trend") in the later stage. Import of young bulls originated from high genetic level of young bulls originated from high genetic level population improved the genetic progress of domestic population. But, the increase of the immigration ratio of imported young bulls ("immigration ratio") did not influence linearly on the progress of the genetic merit of domestic animals. Even if "immigration ratio" was 100%, the genetic merit of domestic animals could not overcome the one of imported young bulls. In the later stage of selection, the genetic merit of domestic animals ran parallel to those of imported young bulls.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.883-887
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• 2000

One way of evaluating the effectiveness of a dairy breeding program is to measure response to selection. This may be direct or indirect. The objectives of this study were to estimate expected progress for direct selection on milk, fat and protein yields; to estimate the expected correlated responses on indirect selection for milk, fat and protein yields in Zimbabwean Holstein cattle and to establish the effect of selection intensity on responses. The Animal Model contained fixed effects of herd, year of calving, calving month, dry period, milking frequency and additive effects pertaining to cows, sires and dams. AIREML software package was used to analyse the data. The genetic and phenotypic parameters obtained in this study were used to compute direct and correlated responses to selection. Because of the higher heritabilities in first parity, genetic progress was found to be greater when selection was practised on first parity cows as compared to later lactations. It is therefore recommended that older cows in the herd be replaced with improved heifers so as to enhance genetic progress.

• Journal of Genetic Medicine
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• v.18 no.2
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• pp.75-82
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• 2021

Speech and language functions are highly cognitive and human-specific features. The underlying causes of normal speech and language function are believed to reside in the human brain. Developmental persistent stuttering, a speech and language disorder, has been regarded as the most challenging disorder in determining genetic causes because of the high percentage of spontaneous recovery in stutters. This mysterious characteristic hinders speech pathologists from discriminating recovered stutters from completely normal individuals. Over the last several decades, several genetic approaches have been used to identify the genetic causes of stuttering, and remarkable progress has been made in genome-wide linkage analysis followed by gene sequencing. So far, four genes, namely GNPTAB, GNPTG, NAGPA, and AP4E1, are known to cause stuttering. Furthermore, thegeneration of mouse models of stuttering and morphometry analysis has created new ways for researchers to identify brain regions that participate in human speech function and to understand the neuropathology of stuttering. In this review, we aimed to investigate previous progress, challenges, and future perspectives in understanding the genetics and neuropathology underlying persistent developmental stuttering.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.4
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• pp.363-370
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• 1996

The effect of breeding length of sire on genetic progress was examined in the Holstein dairy cattle population in Japan. Genetic progress was extimated by gene flow method. Breeding length of sires directly influences the replacement rates of sires and the selection intensity of sires because there are a fixed number of progeny tested young bulls per year. As breeding length of sires increased, rate of gene flow decreased and average proportions of genes deriving from selected animals had lower asymptotic values. When breeding length was short, average proportions of genes required a longer period to converge to asymptotic values. Changes of Rcow-sire's(sire to breed recorded cows) and Ncow-sire's(sire to breed non recorded cows) breeding length influenced not only transmission of their genes but also that of genes derived from all other selected animals. Irrespective of whether the discount rate was assumed to be 0 or 6%, longer term (${\geq}$ 20 years) expected total genetic improvement was maximized by a sire breeding length of five years. For shorter term assessment(10 years), genetic improvement was maximized by a sire breeding length of three years. There was a linear increase in the contribution of the sire to bulls pathway to the total genetic improvement, with increase in the term of assessment.

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.345-352
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• 2000

Food production is a major role of agriculture. It has been projected that the world population continues to increase by the middle of the 21st century, and the population growth results in raising a serious problem of food shortage. Thus we have to increase food as possible. A considerable amount of crops have been abandoned due to short-life after postharvest. Ethylene is a factor responsible for the postharvest loss in crops, especially horticultural crops. If we can reduce ethylene production or sensitivity by genetic engineering, we can develop, so called,“long-life crop”conferring long postharvest lives. During last two decades, intensive research for molecular dissection of ethylene biosynthesis has been carried out, and the researchers have succeeded in engineering ethylene productivity in some crops. On the other hand, after the successful isolation of Arabidopsis ethylene receptor gene ETR1, the homolog genes have been isolated in various plant species. Currently the characterization of these genes and alteration of ethylene sensitivity using the genes are in progress. This review summarizes current progress in the analysis of these genes, and discusses genetic engineering of ethylene sensitivity using these genes.

• Journal of Microbiology and Biotechnology
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• v.16 no.7
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• pp.999-1009
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• 2006

Physiological, biochemical and genetic studies of Corynebacterium glutamicum, a workhorse of white biotechnology used for amino acid production, led to a waste knowledge mainly about amino acid biosynthetic pathways and the central carbon metabolism of this bacterium. Spurred by the availability of the genome sequence and of genome-based experimental methods such as DNA microarray analysis, research on genetic regulation came into focus. Recent progress on mechanisms of genetic regulation of the carbon, nitrogen, sulfur and phosphorus metabolism in C. glutamicum will be discussed.

• Journal of Plant Biotechnology
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• v.36 no.4
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• pp.336-343
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• 2009

Tall fescue is an open-pollinated, perennial, cool season grass species widely used for forage and turf. Tremendous progress has been made in genetic transformation of tall fescue in the past decade. Methods for generating transgenic tall fescue plants have been developed based on biolistic transformation and Agrobacterium-mediated transformation. Potentially useful agronomic genes have been tested to environmental stress tolerance, herbicide tolerance and improve forage quality in tall fescue plants. We review progress in biotechnological improvement of tall fescue and discuss future molecular breeding of this species.

• Molecules and Cells
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• v.45 no.11
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• pp.763-770
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• 2022

Caenorhabditis elegans has been used as a major model organism to identify genetic factors that regulate organismal aging and longevity. Insulin/insulin-like growth factor 1 (IGF-1) signaling (IIS) regulates aging in many species, ranging from nematodes to humans. C. elegans is a nonpathogenic genetic nematode model, which has been extensively utilized to identify molecular and cellular components that function in organismal aging and longevity. Here, we review the recent progress in the role of IIS in aging and longevity, which involves direct regulation of protein and RNA homeostasis, stress resistance, metabolism and the activities of the endocrine system. We also discuss recently identified genetic factors that interact with canonical IIS components to regulate aging and health span in C. elegans. We expect this review to provide valuable insights into understanding animal aging, which could eventually help develop anti-aging drugs for humans.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.25-25
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• 2001

Generation of transgenic fish acquiring the ability to express desirable phenotypes offers new possibilities for addressing fundamental biological questions, and can also attribute to enhanced aquaculture productivity. I describe here the recent research progress in my laboratory with particular emphasis on the development of fast-growing autotransgenic fish and its chromosome-set manipulation using our experimental organism, the mud loach, Misgurnus mizolepis. (omitted)

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.259-268
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• 2000

Senescence is a sequence of biochemical and physiological events that lead to death of a cell, organ, or whole organism. Senescence is now clearly regarded as a genetically determined and evolutionarilly acquired developmental process comprising the final stage of development. However, in spite of the biological and practical importance, genetic mechanism of senescence has been very limited. Through forward and reverse genetic approaches, we are trying to reveal the molecular and genetic mechanism of senescence in plants, employing leaf organs of Arabidopsis as a model system. Using forward genetic approach, we have initially isolated several delayed senescence mutants either from T-DNA insertional lines or chemical-mutagenized lines. In the case of ore 4 and ore 9 mutants, the mutated genes were identified. The recent progress on characterization of mutants and identification of the mutated genes will be reported. We are also screening mutations from other various sources of mutant pools, such as activation tagging lines and promoter trap lines. Two dominant senescence-delayed mutants were isolated from the activation tagging pool. Cloning of the genes responsible for this phenotype is in progress. For reverse genetic approach, the genes that induced during leaf senescence were first isolated by differential screening method. We are currently using PCR-based suppression subtractive hybridization, designed to enrich a cDNA library for rare differentially expressed transcripts. Using this method, we have identified over 35 new sequences that are upregulated at leaf senescence stage. We are investigating the function of these novel genes by systemically generating antisense lines.