• 대한수의사회지
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• 제23권10호
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• pp.663-670
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• 1987

In order to investigate the rate of clinical mastitis and the average number of somatic cell in a milk, the number of somatic cell in the milk counted from 82 normal Holstein cows in the area of Kyungi-Do. And the chemical values of blood were examined fr

• 한국임상수의학회지
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• 제15권2호
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• pp.242-246
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• 1998

These studies were Performed to provide some basic informations for developing an automatic system in dairy farming in order that the farmers may easily and automatically detect the mastitis. Electrical conductivity of each milk sample was measured by micro-ohm meter and also the number of somatic cell was detected by somecounter. The major microorganisms causing mastitis were also investigated. The rate of infected cattle with mastitis was 33.0% among 2,540 dairy cattle and the rate of infected quarters with mastitis was 13.9 % among 9.660 quarters. When the number of somatic cell was under lost electrical conductivity of the milk was 0.073, whereas number of somatic cell was over $3{\times}10^{6}$, electrical conductivity was increased by 0.167. When electrical conductivity of milk was over 0.073, the cattle was diagnosised as mastitis. The major micmorganisms of mastitis were Staphylococcus spp. (55-60%) and Streptococcus spp. (15-20%).

• Asian-Australasian Journal of Animal Sciences
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• 제20권2호
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• pp.166-171
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• 2007

The objective of this study was to assess the association of polymorphisms in ${\kappa}$-cn, ${\beta}$-lg, ${\beta}$-lg 5′ flanking region, CSN1S2, and IGFBP-3 genes with milk production traits and mastitis-related traits in Chinese Holstein. Traits analyzed were 305 day standard milk yield, protein percentage, fat percentage, the ratio of fat percentage and protein percentage, pre-somatic cell count, somatic cell count, and somatic cell score, respectively. CSN1S2 locus was uninformative because only one genotype BB was found in Chinese Holstein. Allele frequencies of A and B in IGFBP-3 gene were 0.5738 and 0.4262 in Chinese Holstein population, which was different from reported Qinchuan cattle population. The genotypes of animals at IGFBP-3 locus significantly affected 305 day standard milk yield, protein percentage, and somatic cell score. The ${\beta}$-lg genotypes had a significant effect on protein percentage and the ratio of fat percentage and protein percentage. Polymorphism in ${\beta}$-lg 5′ flanking region was associated with 305 day standard milk yield, protein percentage, fat percentage, pre-somatic cell count, and somatic cell count. No significant associations of the polymorphism in ${\kappa}$-cn gene were observed for any trait.

• 한국동물위생학회지
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• 제23권1호
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• pp.61-69
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• 2000

Thirty-one dairy cow from two farm(more than 500,000 cells/ml of bulk milk) in Kyongbuk northern province were selected because of their high somatic cell(more than 500,000 cells/ml of milk In individual cow). Each cow received. staphylococcus aureus vaccine(Labac Staph) and immunostimulant(Ultracon) by intramuscular injection to be repeated every fifteen days for S times. The present study was investigated variation of somatic cell after administration of Labac Staph and Ultracon, and antibiotics resistance of isolated staphylococcus spp from milk in selected cow. The results obtained through the survey were summarized as follows ; 1. Ten dairy cow was injected in A farm. Chronic mastitic two cow after 2rd injection was weeded out the herd. Decrease rate of somatic cell after 1st, 2nd, ,3rd, 4th and 5th administration were 41.4%, 35.6%, 56.4%, 65.4% and 36.7%, respectively. Twenty-one cow was injected in B farm. Chronic mastitic five cow after ,3rd injection was weeded out the herd. Decrease rate of somatic cell after 1st, 2nd, 3rd, 4th and 5th administration were 36.9%, 59.9%, 24.5%, 62.6% and 78.4%, respectively. 2. In A farm, isolated staphylococcus spp were identified as S hyicus 2 strains(11.8%), coagulase negative staphylococcus 15 stains(89.2%) and S epidermidis 6strain(35.3%). In B farm, isolated staphylococcus spp were identified as S aureus 19 strains(55.98%) and coagulase negative staphylococcus 15 strains (44.2%). 3. In A fm, antibiotics resistant rate of isolated staphylococcus spp was high at ampicillin, penicillin and kanamycin, and middle at neomycin, streptomycin and erythromycin. in B farm, antibiotics resistant rate was moderate at ampicillin, penicillin, gentamicin, ka-namycin, neomycin, streptomycin, erythromycin and tetracycline, and coagulase negative staphylococcus spp was moderate at streptomycin.

• 한국동물생명공학회지
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• 제37권4호
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• pp.213-217
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• 2022

Haploidization in somatic cells is the process of reducing the diploid somatic chromosomes to haploid. Several studies have attempted somatic haploidization using oocytes in mice and humans. Some researchers showed partial somatic haploidization, but none observed embryo development. Our study attempted somatic haploidization using the modified somatic nuclear transfer (SCNT) protocol with various combinations of chemicals or proteins in mice. This study induced the proper segregation of somatic homologous chromosomes and full embryo development in vitro. Furthermore, somatic haploid embryos established embryonic stem cells and produced live births. The current review summarizes this recent study on the success of somatic haploidization and provides an overview of other related studies on somatic haploidization.

• 식물조직배양학회지
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• 제27권4호
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• pp.245-258
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• 2000

Somatic embryogenesis has become a major tool in the study of plant embryology, as it is possible in culture to manipulate cells of many plant species to produce somatic embryos in a process that is remarkably similar to zygotic embryogenesis. Traditionally, the process has been studied by an examination of the ex vitro factors which influence embryo formation. Later structural, physiological and biochemical approaches have been applied. Host recently, molecular tools are being used. Together, these various approaches are giving valuable information on the process. This article gives an overview of somatic embryogenesis by reviewing information on the morphogenesis, physiology, biochemistry and molecular biology of the process. Topics covered include a brief description of the factors involved in the production of embryogenic cells. Carrot cell suspension is most commonly used, and the development of a high frequency and synchronous system is outlined. At the physiological and biochemical lev-els various topics, including the reactivation of the cell cycle, changes in endogenous growth regulators, amino acid, polyamine, DNA, RNA and protein metabolism, and embryogenic factors in conditioned medium are all discussed. Lastly, recent information on genes and molecular markers of the embryogenic process are outlined. Somatic embryogenesis, the best example of totipotency in plant cells, is not only an important tool in studies in basic biology, but is potentially of equal significance in the micropropagation of economically important plants.

• Asian-Australasian Journal of Animal Sciences
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• 제30권7호
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• pp.944-949
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• 2017

Objective: Investigated the effect and mechanism of ascorbic acid on the development of porcine embryos produced by somatic cell nuclear transfer (SCNT). Methods: Porcine embryos were produced by SCNT and cultured in the presence or absence of ascorbic acid. Ten-eleven translocation 3 (TET3) in oocytes was knocked down by siRNA injection. After ascorbic acid treatment, reprogramming genes were analyzed by realtime reverse transcription-polymerase chain reaction (RT-PCR). Furthermore, relative 5-methylcytosine and 5-hydroxymethylcytosine content in pronucleus were detected by realtime PCR. Results: Ascorbic acid significantly increased the development of porcine embryos produced by SCNT. After SCNT, transcript levels of reprogramming genes, Pou5f1, Sox2, and Klf were significantly increased in blastocysts. Furthermore, ascorbic acid reduced 5-methylcytosine content in pronuclear embryos compared with the control group. Knock down of TET3 in porcine oocytes significantly prevents the demethylation of somatic cell nucleus after SCNT, even if in the presence of ascorbic acid. Conclusion: Ascorbic acid enhanced the development of porcine SCNT embryos via the increased TET3 mediated demethylation of somatic nucleus.

• 한국수정란이식학회지
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• 제17권2호
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• pp.109-115
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• 2002

The present study was conducted for the production of transgenic cloned cows those secrete human lactoferricin into milk by somatic cell nuclear transfer (NT). To estimate detrimental effects of gene transfection on transgenic cloned embryo production, development rates of NT embryos were compared between transfected and non-transfected cumulus and ear fibroblast cells. An expression plasmid for human lactofericin (pbeta-LFC) was constructed by inserting a bovine beta-casein promoter, a green fluorescent protein (GFP) marker gene, and human lactoferricin target gene into a pcDNA3 plasmid. Two bovine somatic cell lines (cumulus cell and ear fibroblast) were established and transfected with the expression plasmid using a liposomal transfection reagent, Fugene6 as a carrier. Cumulus cell and ear fibroblast were transfected at the passage of 2 to 4, trypsinized and GFP-expressing cells were randomly selected and used for somatic cell NT. Developmental competences (rates of fusion, cleavage, and blastocyst formation) in bovine transgenic somatic cell NT embryos reconstructed with non-transfectecd cells were significantly higher than those from transfected cells in cumulus cell and ear fibroblast (P＜0.05). This study indicated that transfection of done. cell has detrimental effect on embryo development in bovine transgenic NT.

• Reproductive and Developmental Biology
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• 제31권2호
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• pp.127-131
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• 2007

Embryonic germ (EG) cells are undifferentiated stern cells isolated from cultured primordial germ cells (PGC). These cells share many characteristics with embryonic stem cells including morphology and pluripotency. Undifferentiated porcine EG cell lines demonstrating capacities of differentiation both in vitro and in vivo have been established. Since EG cells can be cultured indefinitely in an undifferentiated state, whereas somatic cells in primary culture are often unstable and have limited lifespan, EG cells may provide inexhaustible source of karyoplasts in nuclear transfer (NT). In this study the efficiencies of NT using porcine EG and fetal fibroblast cells were compared. Two different techniques were used to perform NT. With conventional NT procedure (Roslin method) involving fusion of donor cells with enucleated oocytes, the rates of development to the blastocyst stage in EG and somatic cell NT were 16.8% (59/351) and 14.5% (98/677), respectively. In piezo-driven microinjection (Honolulu method) of donor nuclei into enucleated oocytes, the rates of blastocyst formation in EG and somatic cell NT were 11.9% (15/126) and 9.4% (9/96), respectively. Regardless of NT methods used in this study, EG cell NT gave rise to comparable rate of blastocyst development to somatic cell NT. Overall, EG cells can be used as karyoplast donor in NT procedure, and embryos can be produced by EG cell NT that may be used as an alternative to conventional somatic cell NT.

• 한국약용작물학회지
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• 제14권4호
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• pp.255-260
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• 2006

본 연구를 통해 헛개나무의 기내유묘의 조직절편으로부터 배발생캘러스의 유기 및 2차 배형성, 그리고 배발생캘러스의 현탁배양계로부터 체세포배를 대량생산하여 식물체로 재분화시키는 시스템을 확립하였다. 현탁배양을 통해 배발생세포의 유도 및 증식에는 모두 $30^{\circ}C$의 고온이 효과적이었는데 이와 같은 온도조건에서 배발생캘러스 유도율과 배발생캘러스의 생장량은 각각 100%와 894.6 mg로 $25^{\circ}C$에 비해 1.53배와 9.19배로 높게 나타났다. 배발생세포를 $18^{\circ}C$에서 배양할 경우 체세포배로 전환되었고 배양 5주후 체세포배로 발달하였으며 $25^{\circ}C$ 이상의 배양온도에서는 배발생세포는 증식만 할뿐 체세포배는 형성되지 않았다. 체세포배로부터 식물체의 형성은 $18^{\circ}C$ 저온에서만 가능하였다. 배지에 0.1과 0.5 mg/l BA를 첨가할 경우 식물체 재분화율은 37%와 28%로 생장조절물질을 처리하지 않은 배지에 비해 2.2배와 1.7배로 높게 나타났다 재분화된 식물체의 성장에 주는 무기염의 영향을 조사하기 위하여 유식물체를 MS와 1/3MS 고체배지에 옮겨 배양한 결과 1/3MS배지가 줄기신장과 뿌리의 유도에 적합하였다.