• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1560-1564
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• 2003

The study was carried out in Sahiwal, Holstein Friesian, Jersey and crossbred cattle to find out the effect of genotype of beta-lactoglobulin gene on milk production traits. The polymorphism at beta-lactoglobulin gene was identified by conducting PCRRFLP studies. A 398 bp fragment of the gene was amplified and digested with Hae III restriction enzyme. The two alleles A and B and three genotypes AA, AB and BB were identified in all cattle breeds. The frequency of B allele was comparatively higher than that of A allele. The AA genotype produced significantly higher milk yield in Sahiwal cattle whereas BB genotype yielded higher milk in Holstein friesian cattle. In other cattle breeds the genotypic effect was non-significant. In conclusion it may be stated that the genotype with significantly higher milk yield may be favoured in the farm along with other conventional selection criteria to enhance the milk production of animals.

• The Korean Journal of Zoology
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• v.38 no.3
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• pp.426-432
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• 1995

Expression of $\beta$-lactoglobulin gene in mammary tissue is strongly induced by lactogenic hormones such as prolactin, glucocorticoid, and insulin. In order to elucidate the regulatory mechanism underlying such hormonal induction, the response of the caprine $\beta$-lactoglobulin gene promoter to lactogenic hormones was analyzed in cultured HC11 mammary cells. Expression with serial deletions of the 5' -regulatory sequence of the $\beta$-lactoglobulin promoter revealed that two regions are responsible for a substantial change in hormonal indudbility. The region upstream of-1692, which exhibited strong repression of the downstream promoter, mediated the induction by insulin. This insulin-response was independent of the other two lactogenic hormones, prolactin and glucocorticoid. The other region from -740 to -470, which showed strong activation of the $\beta$-lactoglobulin promoter in confluent HC11 mammary cells, mediated mainly the response to a glucocorticoid analogue, dexametasone. The induction by the latter region, however, was suppressed by the usptream repression without insulin treatment. These results suggest that the induction of $\beta$-lactoglobulin promoter activity by lactogenic hormones in mammary cells may be achieved by the combined action of derepression by in sulin and activation by glucocorticoid and prolactin. Dexametasone response by the latter region seems to be mediated by the glucocorticoid receptor site around -7OObp.

• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.216-224
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• 1998

This study was performed to offer the basic and applicable data for improvement of Korean cattle and dairy cattle, according to finding the genetic construction obtained from analysis of genetic polymorphisms of ${\beta}$-lactoglobulin and ${\kappa}$-casein loci related Korean cattle and Holstein cows using PCR-RFLP. Genomic DNA used in this study was prepared from the blood of 253 individuals of Korean cattle in Korean Native Cattle Improvement Center, NLCF, and the blood of 113 individuals of Holstein cows in National Livestock Research Institute. The results obtained are summarized as follows : 1. This study confirmed amplified products of 530bp and 262bp fragments obtained from the amplification of ${\beta}$-lactoglobulin and ${\kappa}$-casein loci in Korean cattle and Holstein breed by PCR. 2. The ${\beta}$-lactoglobulin AA genotype showed 153bp and 109bp fragments, and ${\beta}$-lactoglobulin AB genotype showed 153bp, 109bp, 79bp and 74bp fragments, and BB genotype showed 109bp, 79bp and 74bp fragments in amplified products of ${\beta}$-lactoglobulin loci with the restricted enzyme digestion of Hae III. 3. The ${\kappa}$-casein AA genotype showed a 530bp fragment, and ${\kappa}$-casein AB genotype showed 530bp, 344bp and 186bp fragments, and BB genotype showed 344bp and 186bp fragments in amplified products of ${\kappa}$-casein loci with the restricted enzyme digestion of Taq I. 4. On ${\beta}$-lactoglobulin genotypes and gene frequencies, Korean cattle were 6.72%, 26.09% and 67.19% for AA, AB and BB genotypes, and ${\beta}$-lactoglobulin A and B alleles were 0.197 and 0.803, and Holstein were 35.40%, 56.64% and 7.96% for AA, AB and BB genotypes, and ${\beta}$-lactoglobulin A and B alleles were 0.637 and 0.363, respectively. 5. On ${\kappa}$-casein genotypes and gene frequencies, Korean cattle were 46.25%, 39.13% and 14.62% for AA, AB and BB genotypes, and ${\kappa}$-casein A and B alleles were 0.658 and 0.342, and Holstein were 60.18% and 38.94% and 0.88% for AA, AB and BB genotypes, and ${\kappa}$-casein A and B alleles were 0.796 and 0.204, respectively. 6. As a consequence, the gene frequency was 0.197 and 0.803 for ${\beta}$-lactoglobulin A and B alleles, and 0.658 and 0.342 for ${\kappa}$-casein A and B alleles in Korea cattle, but was 0.637 and 0.363 for ${\beta}$-lactoglobulin A and B alleles, and 0.796 and 0.204 for ${\kappa}$-casein A and B alleles in Holstein, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.2
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• pp.187-194
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• 1995

Genetic variants of ${\alpha}s_1$-casein, ${\beta}$-casein, ${\kappa}$-casein and ${\beta}$-lactoglobulin were investigated by starch urea gel electrophoresis in milk samples of 280 Korean native cattle. A new ${\beta}$-casein variant, designated ${\beta}$-casein $A^4$, was found in milk samples of Korean native cattle. It has a much slower electrophoretic mobility than the ${\beta}$-casein $A^3$ variant in acid gel. This new variant appeared together with either ${\beta}$-casein $A^1$, $A^2$ or B variant. Gene frequencies and genotypic frequencies were estimated. Gene frequencies of four milk protein loci in Korean native cattle were compared with those of imported cattle breeds raised in Korea and Japanese brown cattle. Gene frequencies were ${\alpha}s_1$-casein B .846, ${\alpha}s_1$-casein C .154; ${\beta}$-casein $A^1$ .216, ${\beta}$-casein $A^2$ .666, ${\beta}$-casein $A^4$ .048, ${\beta}$-casein B .070; ${\kappa}$-casein A .648, ${\kappa}$-casein B .352; ${\beta}$-lactoglobulin A .148, ${\beta}$-lactoglobulin B .852. The population was in Hardy-Weinberg equilibrium at all milk protein loci. Gene frequencies of Korean native cattle were very similar to those of Japanese brown cattle. Interestingly, a new variant, ${\beta}$-casein $A^4$, was found only in Korean native cattle and Japanese brown cattle. These results support the hypothesis that Korean native cattle were used in the development of the Japanese brown cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.6
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• pp.733-736
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• 2004

The study was carried out on eight Bos indicus cattle breeds namely, Sahiwal, Tharparkar, Nimari, Khilari, Deoni, Amritmahal, Hariana and Hilly cattle; two Bos taurus cattle breeds namely, Jersey and Holstein Friesian and Indicine${\times}$Taurine crossbred cattle to find out the polymorphic pattern of beta-lactoglobulin gene. The polymorphism at beta-lactoglobulin gene was detected by conducting PCR-RFLP studies on 398 bp fragment spanning over 104 bases of exon IV and 294 bases of intron IV. Two alleles A and B and three genotypes AA, AB and BB were observed in all the cattle breeds. The frequency of B allele was comparatively higher than that of A allele. The allelic frequency of A varied from 0.20 to 0.30 in Bos indicus cattle breeds and 0.19 to 0.34 in Bos taurus breeds while in crossbred cattle the frequency was estimated as 0.21. The weighted frequency of A allele was highest in Indian cattle and lowest in crossbred cattle while the frequency in taurine cattle was found to be in between indicus and crossbred cattle. The non-significant differences of allelic frequency amongst Bos indicus, Bos taurus and crossbred cattle was observed. The effect of genotype on fat percentage was also found to be non-significant in cattle.

• Korean Journal of Agricultural Science
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• v.28 no.2
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• pp.78-84
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• 2001

This study was analyzed by PCR technique with specific primer in order to investigate the characteristics of ${\beta}$-lactoglobulin (${\beta}$-LG) gene 5'flanking region in Korean native goat. This work confirmed amplified product of 1,077 bp fragments obtained from the amplification of ${\beta}$-LG promoter from genomic DNA using PCR in Korean native goat. The nucleotide sequence of ${\beta}$-LG gene 5'flanking region in Korean native goat as compared with that of sheep ${\beta}$-LG were different at 46 base of 897 nucleotides, and showed high homology as about 94.9% each breed. Especially we confirmed that the difference of nucleotide sequences between Korean native goat and sheep were consisted of $T{\rightarrow}C$ substitution and $C{\rightarrow}T$ substitution reversely. As a consequences, the sequences of ${\beta}$-LG gene 5'flanking region showed a high homology between Korean native goat and sheep. Furthermore we should be studied that relationships between the control of gene expression and nucleotide sequences of transcription factor in Korean native goat.

• The Korean Journal of Zoology
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• v.38 no.3
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• pp.433-441
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• 1995

Mammary tissue-specificity of the caprine $\beta$-lactoglobulin promoter appears to be secured by repression in non-expressing cells. In order to identify the mechanism of the negative regulation, the upstream promoter sequence of the caprine $\beta$-lactoglobulin gene was analyzed in detail. The repression was mediated by the upstream flanking sequence from -47O to -205. The sequence could repress the promoter activity of $\beta$-lactoglobulin in either orientation. The effect of the putative negative regulation element of caprine $\beta$-lactoglobulin on heterlogous promoters, however, varied: the promoter activity of herpes simplex virus thimidine kinase was either repressed or activated by the sequence depending on its orientation, while the SV4O early promoter was activated rather than repressed. The regulatory sequence involving the putative negative regulatory element was strongly shifted with the nuclear extract from non-mammary HeLa and CV-1 cells, while only weak shift was observed with that of mammary HC11 cells. Such correlation between repression and factor binding suggests that the protected regions in foot-printing assay may be the negative regulatory elements of $\beta$-lactoalobulin that serve tissue-specific repression.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.10
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• pp.1397-1401
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• 2003

The aim of this study was to determine genotypes of four genetic markers and to investigate their association with milk production traits in Brown Swiss cattle imported to Slovakia. The bovine $\kappa$-casein, $\beta$-lactoglobulin, growth hormone and prolactin genotypes of 107 cows were identified by polymerase chain reaction. Effects all four genetic markers on milk, fat, protein and lactose yields and fat, protein and lactose percentage were estimated from a data set of 249 lactations. The frequency of desirable B allele of $\kappa$-casein gene to milk production was 0.46, alleles A of $\beta$-lactoglobulin gene was 0.55, allele and L of growth hormone gene was 0.45 and allele A and B of bovine prolactin gene were 0.61 and 0.39. The results of milk production obtained in our work showed that BB genotypes of $\kappa$-CN gene, AA genotypes of $\beta$-LG gene, LL genotypes of bGH gene were significantly associated with better milk production traits, mainly about the fat content. Association of a bovine prolactin genotypes with milk production were not found.

• Animal cells and systems
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• v.1 no.2
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• pp.345-350
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• 1997

The ${\beta}$-Lactoglobulin (BLG) gene expression is differentially regulated during development of the mammary tissues. Such differential regulation of the BLG gene expression can be reiterated in the cultured mammary HC11 cells. In the growing non-confluent HC11 cells, the BLG promoter activity was shown to be partially repressed by the upstream regulatory sequence. The repression was gradually diminished and switched to activation as the cells grew confluent. The differential regulation of the BLG promoter was controlled by the 5'-regulatory sequence located at the upstream of 205 bp. Electromobility shift assay showed that nuclear extract from HC11 cells differentially bound on the regulatory sequence, depending on the cell confluency, which was in accordance with the differential transcriptional activity. DNase I foot-print assay, however, revealed that all nuclear extracts presented the same foot-prints, regardless of confluency of HC11 cells. These results suggest that differential regulation BLG gene expression by the 5'-regulatory sequence may be accomplished by competitive and/or cooperative binding of differential regulatory factors on the same regulatory element.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.285-294
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• 1992

Biochemical polymorphisms of sow's milk proteins, $\beta$-casein ($\beta$-CN), $\beta$-lactoglobulin ($\beta$-LG), post-lactoglobulin (post-LG), $\alpha$-lactalbumin ($\alpha$-LA) and X-protein, as genetic markers for major pig breeds (Landrace, Yorkshire, Duroc, Hampshire and cross bred) in Korea were determined by starch gel electrophoresis. Phenotype and gene frequencies at all marker loci were estimated and genetic differences among breed populations were analyzed. Three $\beta$-CN phenotypes (AA, AB and BB) controlled by two codominant alleles (${\beta}-CN^A$ and ${\beta}-CN^B$), four $\beta$-LG phenotypes (AA, AC, $AC^{\pm}$ and CC) controlled by two codominant alleles (${\beta}-LG^A$ and ${\beta}-LG^C$) and ten X-protein phenotypes (AA, BB, CC, DD, AB, AC, AD, BC, BD and CD) controlled by four codominant alleles ($X^A,\;X^B,\;X^C\;and\;X^D$) were identified. In addition, a genetically controlled polymorphism of post-LG was found for the first time in sow's milk protein. Three different phenotypes (AA, AB and BB) were designated $post-LG^A$ and $post-LG^B$. Of the five marker loci examined, $\alpha$-LA locus was observed to lack any individual variation in all breeds studied. All populations were in Hardy-Weinberg equilibrium for all loci. There were marked breed differences for phenotype and gene frequencies in the post-LG and X-protein marker loci. However, there were little differences between breeds in the gene frequencies at the $\beta$-CN and $\beta$-LG marker loci.