• Molecules and Cells
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• v.23 no.1
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• pp.72-79
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• 2007

Demand for low-input sustainable crop cultivation is increasing to meet the need for environment-friendly agriculture. Consequently, developing genotypes with high nutrient use efficiency is one of the major objectives of crop breeding programs. This study was conducted to identify QTLs for traits associated with physiological nitrogen use efficiency (PNUE). A recombinant inbred population (DT-RILs) between Dasanbyeo (a tongil type rice, derived from an indica ${\times}$ japonica cross and similar to indica in its genetic make-up) and TR22183 (a Chinese japonica variety) consisting of 166 $F_8$ lines was developed and used for mapping. A frame map of 1,409 cM containing 113 SSR and 103 STS markers with an average interval of 6.5 cM between adjacent marker loci was constructed using the DT-RILs. The RILs were cultivated in ordinary-N ($N-P_2O_5-K_2O=100-80-80kg/ha$) and low-N ($N-P_2O_5-K_2O=50-80-80kg/ha$) (100 kg/ha) conditions. PNUE was positively correlated with the harvest index and grain yield in both conditions. Twenty single QTLs (S-QTLs) and 58 pairs of epistatic loci (E-QTLs) were identified for the nitrogen concentration of grain, nitrogen concentration of straw, nitrogen content of shoot, harvest index, grain yield, straw yield and PNUE in both conditions. The phenotypic variance explained by these S-QTLs and E-QTLs ranged from 11.1 to 44.3% and from 16.0% to 63.6%, respectively. The total phenotypic variance explained by all the QTLs for each trait ranged from 35.8% to 71.3%, showing that the expression of PNUE and related characters depends signify- cantly upon genetic factors. Both S-QTLs and E-QTLs may be useful for marker-assisted selection (MAS) to develop higher PNUE genotypes.

• Korean Journal of Animal Reproduction
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• v.21 no.2
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• pp.85-93
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• 1997

These experiments were carried out to examine the development capacity of sexed and then bisected embryo from 8-cell to morula stage. Antisera to histocompatibility-Y(H-Y) antigen were prepared in inbred SD female rat by repeated immunization of spleen cell or testis supernatant from males of same strain. Male and female embryos were separated by delaying development of embryos against H-Y antibody. After sexing, rabbit embryos were bisected and aggregated. The results obtained from the these experiments were summuerized as follows: 1. When mouse and rabbit 8-, 16-cell and morular embryos were culature in H-Y antiserum, the ratio of embryo which has developed to hatching blastocyst was 53.4, 46.3 and 57.4% in mouse embryos, and 49.0, 52.0 and 61.0% in rabbit embryo, respectively. The ratio of mouse and rabbit embryos developed to hatching blastocyst showed nearly natural sex rate(50%), except rabbit mourla showed a little higher ratio(61.0%) as compared to natural sex ratio. 2. When rabbit demi-embryos from 8-, 16-cell embryo and morula were cultured, the percentage of demi-embryos was 70, 68 and 58% without zona pellucida removed, and 62, 69 and 51% with zona pellucida. The rate of aggregation was higher in 8- and 16-cell demi-embryos than in morula demi-embryo. 4. When sexed-demi-embryo was aggregated with another demi-embryo with demi-embryo with same sex, the rate of embryo developed to blastocyst was 60, 50 and 25%, respectively. Eight-cell demi-embryo showed highest rate. In conclusion, it showed that H-Y antiserum which was made by rat spleen cell enabled sexing rabbit embryos. And when rabbit sexed 8-, 16-cell and morula demi-embryo were aggregated, they were developed to eu-blastocyst which suggested the potential of sexed embryo manipulation.

• Journal of the Korean Society of Food Culture
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• v.18 no.3
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• pp.202-210
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• 2003

The purpose of this study was to investigate the effects of dietary purple sweet potato(Ipomoea batatas) powder on serum lipid levels and antioxidative enzymes in normal and pretective effect on hepatotoxicity rats induced by carbon tetrachlolide. Four groups of rats (3-week-old inbred Sprague-Dawley male rats) were normal rats fed control diet(C), induced hepatotoxicity rats fed control diet(EC), normal rats fed purple sweet potato diet(P), and induced hepatotoxicity rats fed purple potato sweet diet(EP). Rats were induced by single injection of 50% carbon tetrachlolide(0.1 mL/100 g B.W., i.p.). The rats were fed ad libitum each of the experimental diet for 5 weeks. After 5 weeks the rats were sacrificed and activities of antioxidant enzymes and lipid peroxidation products were determined in their liver homogenates. But serum concentrations of lipid was not significant in all groups. Serum alanine aminotransferase(ALT/GPT) and aspartate aminotransferase(AST/GOT) of the EC and EP groups were heigher than the C and P groups. The hepatic glucose 6-phosphatase(G6Pase) activity of the group fed purple potato diet(P) was lower than the other groups(p<0.05). However, The glutathione peroxidase(GPx) activities was not statistically different between the groups. Renal glutathione S-transferase(GST) activity of the EC and EP groups were lower than the C and P groups(p<0.05). In conclusion, these results suggest that purple sweet potato is believed to be possible protective effect on hepatotoxicity rats induced by carbon tetrachlolide.

• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.1
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• pp.7-14
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• 2006

A breeding programme was initiated during 2001 to introduce sex-limited larval markings to a productive multivoltine breed - BL67 from an inbred sex-limited line, MY1 (SL) maintained at Central Sericultural Research and Training Institute, Mysore. Introgressive hybridization, recurrent backcrossing for six generations followed by sib-mating resulted in synthesis of a new multivoltine silkworm breed BL67 (SL) with sex-limited larval markings. The new breed was studied for combining ability by crossing with eight bivoltine breeds viz., $NB_4D_2,\;CSR_2,\;CSR_2 (SL),\;CSR_2,\;CSR_4,\;CSR_8,\;CSR_{18}\;and\;CSR_{19}$. General combining ability effects of the new breed showed its superiority over the popular Pure Mysore by expressing significant GCA effects for six out of twelve characters whereas the results are on par with the original multivoltine breed. The hybrid $BL67(SL){\times}CSR2(SL)$ excelled in several quantitative characters such as pupation rate (90.2%), cocoon weight (1.97 g), cocoon shell weight (40 cg), cocoon shell ratio (20.3%), filament length (918 m), denier (2.96), raw silk percentage (14.96%) and neatness (90 p). Studies on cocoon size variability revealed that the cocoons of $BL67(SL){\times}CSR2(SL)$ were found comparatively uniform showing less standard deviation of 6.55 and co-efficient of variation of 3.91 %. The suitability of newly developed breed for easy grain age operation and commercial exploitation with promising hybrid have been discussed.

• Animal Systematics, Evolution and Diversity
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• v.36 no.2
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• pp.154-158
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• 2020

The Asian crested ibis Nipponia nippon is one of the world's most endangered species. Except for the Sanxii population from China, it is known that all of the crested ibis populations from East Asia have been extinguished. In these days, most of them are being inbred as captive populations in China, South Korea, and Japan, which caused their low expected genetic diversity. Microsatellite markers are well known as a suitable DNA marker for exploring genetic diversity among captive populations of a variety of endangered species. In the present study, ten microsatellite markers were developed for the captive populations of the South Korean crested ibis, which were employed to examine the level of genetic diversity with the two founders from Sanxii, China and the 70 descendants of them. As a result, the mean number of gene diversity, observed heterozygosity, and expected heterozygosity of the captive population were 0.70, 0.84, and 0.70 respectively. It revealed that the captive population of South Korea is as genetically more stable than we expected. In addition, the principal coordinates analysis and genetic structure analyses showed that the captive population of N. nippon can be divided into the two different genetic groups. The developed microsatellite markers here could be helpful for crested ibis conservation in East Asian countries such as China and Japan as well as South Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.1
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• pp.24-31
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• 2017

We screened the drought tolerant maize using seventeen maize genotypes from different sources, nine inbred genotypes from United States Department of Agriculture (USDA) (B73, CML103, CML228, CML277, CML322, CML69, Ki3, Ki11, and NC350), three Southeast Asian genotypes (DK9955, LVN-4, and 333), and five Korean hybrids (Cheongdaok, Gangdaok, Ilmichal, Kwangpyeongok, and Pyeonganok). We evaluated anthesis-silking interval (ASI), leaf senescence (LS), ears per plant (EPP), tassel length (TL), and fresh weight (FW) at silking date. According to ASI and LS examination, CML103 and Kill were drought tolerant genotypes, wheareas Ki3 and 333 were drought susceptible. EPP, TL, and FW differed according to drought resistance. Grain yield was correlated strongly with ASI, but moderately with LS. Difference in ASI between drought-stressed (DS) and well-watered (WW) conditions was less than three days in CML228, CML103, Cheongdaok, NC350, B73, Ki11, CML322, and Kwangpyeongok, whereas that of Ki3, Pyeonganok, and Gangdaok was more than 6.5 days. We concluded that CML228, CML103, Cheongdaok, NC350, B73, Ki11, CML322, and Kwangpyeongok are drought tolerant genotypes, whereas Ki3, Pyeonganok, and Gangdaok are drought susceptible.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.9
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• pp.1368-1372
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• 2014

Several studies arduously reported that gayal (Bos frontalis) is an independent bovine species. The population size is shrinking across its distribution. In Bangladesh, it is the only wild relative of domestic cattle and also a less cared animal. Their body size is much bigger than Bangladeshi native cattle and has prominent beef type characters along with the ability to adjust in any adverse environmental conditions. Human interactions and manipulation of biodiversity is affecting the habitats of gayals in recent decades. Besides, the only artificial reproduction center for gayals, Bangladesh Livestock Research Institute (BLRI), has few animals and could not carry out its long term conservation scheme due to a lack of an objective based scientific mission as well as financial support. This indicates that the current population is much more susceptible to stochastic events which might be natural catastrophes, environmental changes or mutations. Further reduction of the population size will sharply reduce genetic diversity. In our recent investigation with 80K indicine single nucleotide polymorphism chip, the $F_{IS}$ (within-population inbreeding) value was reported as $0.061{\pm}0.229$ and the observed ($0.153{\pm}0.139$) and expected ($0.148{\pm}0.143$) heterozygosities indicated a highly inbred and less diverse gayal population in Bangladesh. Prompt action is needed to tape the genetic information of this semi-domesticated bovine species with considerable sample size and try to investigate its potentials together with native zebu cattle for understanding the large phenotypic variations, improvement and conservation of this valuable creature.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.10
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• pp.1363-1367
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• 2005

A pedigree file of 4,738 records of a purebred flock of Muzaffarnagari sheep, maintained at Central Institute for Research on Goats (CIRG), Makhdoom, for a period of 24 years (1978 to 2001) was used to calculate inbreeding coefficients. The lambtraits studied were birth, 3, 6, 9 and 12 months weights as well as 6 and 12 months fleece yields. The lambs' and ewes' inbreeding coefficients ranged from 0 to 26.4% and 0 to 25%, respectively. The average inbreeding coefficient of lambs was higher than that of ewes in all periods as expected in a closed flock. Fluctuations in lamb and ewe inbreeding were observed in the periods under study. The percentages of animals in the higher inbred categories varied somewhat but generally were relatively constant. The mean rate of inbreeding was 0.63% per generation. The effective population size of the flock was 79.1. On average, an increase of 1% individual inbreeding significantly (p<0.05) reduced weights at birth by 0.010 kg, at 3 month by 0.048 kg, at 6 month by 0.075 kg, at 9 month by 0.129 kg and at 12 month by 0.112 kg. Ewes' inbreeding had non-significant effects on body weight at all ages. Effects of both lambs' and ewes' inbreeding had negative but non-significant effects on fleece weights at 6 and 12 months of age. Thus, inbreeding depression in lambs significantly reduced body weights from birth to 12 months of age but had a negligible effect on fleece yields.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.2
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• pp.157-162
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• 2018

Objective: The aim of this study is to identify single nucleotide polymorphisms (SNPs) and genes related to pig IMF and estimate the heritability of intramuscular fat content (IMF). Methods: Genome-wide association study (GWAS) on 704 inbred Berkshires was performed for IMF. To consider the inbreeding among samples, associations of the SNPs with IMF were tested as random effects in a mixed linear model using the genetic relationship matrix by GEMMA. Significant genes were compared with reported pig IMF quantitative trait loci (QTL) regions and functional classification of the identified genes were also performed. Heritability of IMF was estimated by GCTA tool. Results: Total 365 SNPs were found to be significant from a cutoff of p-value <0.01 and the 365 significant SNPs were annotated across 120 genes. Twenty five genes were on pig IMF QTL regions. Bone morphogenetic protein-binding endothelial cell precursor-derived regulator, forkhead box protein O1, ectodysplasin A receptor, ring finger protein 149, cluster of differentiation, tyrosine-protein phosphatase non-receptor type 1, SRY (sex determining region Y)-box 9 (SOX9), MYC proto-oncogene, and macrophage migration inhibitory factor were related to mitogen-activated protein kinase pathway, which regulates the differentiation to adipocytes. These genes and the genes mapped on QTLs could be the candidate genes affecting IMF. Heritability of IMF was estimated as 0.52, which was relatively high, suggesting that a considerable portion of the total variance of IMF is explained by the SNP information. Conclusion: Our results can contribute to breeding pigs with better IMF and therefore, producing pork with better sensory qualities.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.16
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• pp.6721-6726
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• 2014

Background: The aim of this preliminary study was to address variations of responses observed with different starting tumor sizes of 10 and 15 mm, and the effects of different doses of tamoxifen (TAM) on experimental rat mammary tumors. Materials and Methods: Thirty-five inbred female Sprague Dawley rats aged 43 days were administered with three weekly doses of N-methyl-N-nitrosourea (NMU) intraperitoneally (ip) at 50 mg/kg body weight. Animals were randomized (beginning from 10 mm tumor size) into four TAM-treated (50, 100, 200 and $500{\mu}g/day$) groups of six animals each, and another group (n=6) treated with TAM $100{\mu}g/day$ at starting tumour size of 15 mm. The animals were treated by oral gavage daily for 8 weeks before sacrifice. Results: Serum urea and creatinine, and overall physical tumor burden were significantly modulated in animals treated with variable doses of TAM compared to the untreated controls (n=5). Final body weight and tumor number were significantly different in the 10 mm-treated animals compared to those treated at 15 mm. There were no significant differences in histopathological features among all the groups. Conclusions: Our findings suggest the importance of standardizing tumour size and drug doses before initiation of treatment, particularly in the direct comparison of basic end-tumour physical parameters.