• Proceedings of the KSAR Conference
• /
• 2000.10a
• /
• pp.7-8
• /
• 2000

Transgenic animals are very useful for scientific, pharmaceutical, and agricultural purposes. In livestock, transgenic technology has been used forthe genetic alteration of farm animals, the production of human proteins inlarge quantities in the milk of transgenic farm animals, and the generation of animals with organs suitable for xenotransplantation. To date, the transfer of foreign genes into farm animals has been performed mainly by microinjection of DNA into the pronuclei of fertilized eggs. However, the overall success rate of transgenic animals in livestock so far has been disappointingly low, eg., the efficiency is 0∼5% in swine, and less than 1% in sheep and cattle, compared with the rate in mice where 5% microinjected develop into transgenic animals. Recently, McGreath et al. (2000) have succeeded in producing the gene targeted sheep by the use of nuclear transfer from cultured somatic cells transfected with a foreign gene in vitro. However, we may need plenty of time until currently employ this method for gene transfer to farm animals. We have been studying to exploit the method for improving production efficiencies of transgenic animals with emphasis of its application to farm animals. The present paper describes three approaches that we have made in our laboratory to improve production efficiencies of transgenic animals, based on the DNA microinjection method. 1. Co-injection of restriction enzyme with foreign DNA into the pronucleus for elevating production efficiencies of transgenic animals. 2. Efficient selection of transgenic mouse embryos using EGFP as a marker gene. 3. Phenotypes of tansgenic mice expressing WAP/hGH-CAG/EGFP fusion gene produced by selecting transgenic embryos. 4. Efficient site-specific integration of the transgene targeting an endogenous lox like site in early mouse embryos.

• Korean Journal of Veterinary Research
• /
• v.29 no.1
• /
• pp.27-35
• /
• 1989

To develop more specific and sensitive diagnostic methods for infectious bovine rhinotracheitis, 7-C-2 monoclonal antibody specific to polypeptides of infectious bovine rhinotracheitis virus (IBRV) was applied in indirect immunofluorescence antibody assay (IFA), indirect immunoperoxidase assay(IPA) and radial immunodiffusion enzyme assay (RIDEA). It was found that IBRV infected in MDBK cells could be detected as early as 8 hours post infection by IFA, and that IFA was more rapid and specific to identify IBRV antigen than IPA. The diagnostic efficacy of RIDEA and SN test was studied with 88 bovine sera. It was evident that RIDEA could eliminate the false positive reaction encountered in serum neutralization(SN) test, being more rapid and sensitive than the latter. Highly significant correlation coefficiency (r=0.76, p<0.01) was evaluated between the titers of sera and the diameters of RIDEA. Tracheal membranes and sera collected from 96 slaughtered cattle with lesions in respiratory organs were examined to detect IBRV antigen and antibody by IFA, RIDEA and SN test. It was presented that positive rates were 32.3% in IFA, 20.8% in RIDEA and 21.9% in SN test, and that coincidence rate between RIDEA and SN test were 100% in positive sera and 98.7% in negative sera. In conclusion, it was assumed that application of monoclonal antibody could improve the diagnostic efficacy of IBR by enhancing sensitivity and specificity of IPA, IFA and RIDEA.

• Korean Journal of Medicinal Crop Science
• /
• v.26 no.2
• /
• pp.157-169
• /
• 2018

Background: Cassia tora L., an annual or perennial plant of the Fabaceae family, is traditional medicine with various biological activities, including anti-constipation and, anti-inflammation. Chemical compounds such as anthraquinone glycoside and naphthalene derivatives have been isolated from this plant. Cassia tora L. is a common contaminant of agricultural commodities, but is toxic to cattle and poultry. Methods and Results: To investigate the potential toxicity, Cassia tora L. aqueous extract (CO) was administered orally to rats for 26 weeks at 0 (control), 300, 1,500 and 3,000 mg/kg/day (n = 10 for male rats for each dose). The positive control comprised animals orally administered anthraquinone 100 mg/kg/day. There was no treatment-related mortality. An increase in the kidney weight was observed at 3,000 mg/kg/day of CO and anthraquinone 100 mg/kg/day. Macrophage infiltration in the colon was observed at CO 1,500 and 3,000 mg/kg/day and anthraquinone 100 mg/kg/day, but there were no significant toxicological changes in the incidence and severity of the finding. Conclusions: The oral no-observed-adverse-effect level (NOAEL) of CO was 3,000 mg/kg/day in male rats and no target organs were identified. In addition, 300 mg/kg was found to be the no-observed-effect level (NOEL) for systemic toxicity under the conditions of the study.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.2
• /
• pp.155-160
• /
• 2000

In order to understand the effects of sex or age on cellular characteristics of adipocytes from Hanwoo and sheep, samples were obtained from omental, subcutaneous, intermuscular and intramuscular adipose tissue depots of bulls, steers, heifers and cows in Hanwoo, and perirenal, omental and subcutaneous adipose tissues of fetal lambs, suckling lambs and wethers in sheep. In case of Hanwoo, mean diameter, surface area and volume of adipocytes from each depot were obtained by multisizer II (Coulter Co., UK). Osmium-fixed adipocytes were sized and counted using $560{\mu}m$ aperture. For samples obtained from sheep, cellularity was measured by using microscope and MCV program of Texas Instrument. Bulls had less subcutaneous and kidney fat than steers even though their slaughter and carcass weight were heavier. The amounts of fat from cows were greater in subcutaneous, kidney and internal organs than heifers. Steers had larger adipocytes in subcutaneous, intermuscular and intramuscular adipose tissues than bulls, although the differences were significant only for the subcutaneous adipose tissue depots. Adipocytes appeared to be largest in omental and smallest in intramuscular adipose tissue, although there were no significant differences among tissues. In a comparison of heifers and cows, significant site effects (p<0.05) were shown in adipocyte diameter, surface area and volume, and adipocyte appeared to be largest in omental tissue. Statistical difference (p<0.05) was only shown in cell volume of intramuscular tissue which was higher in cow than heifer. Intramuscular adipose tissue tended to have relatively greater numbers of cells per gram tissue and reflect lesser maturity of intramuscular adipose tissue relative to other adipose tissues. In sheep, regardless of adipose tissue depots, wethers had the greater adipocyte diameters than those at any other growth stage of sheep. Within adipose depots, the ranking of cell size was the greatest in the omental tissue of wether and the lowest in the renal and subcutaneous adipose tissue depots of fetal lamb. The cell size of adipocyte became larger with age, especially from fetal to suckling lamb due to a rapid hypertrophy of both perirenal and subcutaneous adipocytes during the suckling period.

• Food Science of Animal Resources
• /
• v.28 no.5
• /
• pp.651-659
• /
• 2008

This study aimed to develop polyclonal antibodies to regional inedible adipocytes of Korean native cattle (Hanwoo) and investigate cross-reactivity of the antibodies. Patterns in plasma membrane proteins (PMPs) from abdominal and subcutaneous adipocytes of Hanwoo isolated by collagenase digestion were investigated using SDS-PAGE. As antigens, abdominal and subcutaneous adipocyte PMPs of Hanwoo were injected to sheep 3 times at 3 wk intervals for passive immunization, and non-immunized serum and antisera were collected before and after the injections. Titers of the antisera obtained from sheep and their cross-reactivities with heart, kidney, liver, lung, muscle, and spleen of Hanwoo were determined by ELISA. Isolation and culture of abdominal and subcutaneous adipocytes of Hanwoo were performed for analysing LDH concentration. Based on the SDS-PAGE analysis, specific proteins of PMPs in abdominal and subcutaneous adipocytes appeared despite rather similar patterns between both adipocytes. At the level of 1:1,000 dilution, little antibody reactivity appeared in non-immunized serum whereas the antisera had relatively strong reactivity up to the level of 1:128,000 and 1:64,000 dilution. These findings may indicate that strong antibodies against adipocyte PMPs can be developed using an immunological approach. Extremely low reactivities of abdominal and subcutaneous adipocyte antisera were detected with PMPs of the organs. Both antisera strongly reacted with each adipocyte PMPs and showed statistically (p<0.01) higher cross-reactivities compared with non-immunized serum. In conclusion, these results may indicate that the present polyclonal antibodies against regional inedible adipocyte PMPs are well developed and have safety in cross-reactivities with body organs. Further studies on in vivo cross-reactivity and fat reduction of the antibodies against abdominal and subcutaneous adipocytes PMPs of Hanwoo should be required for inedible fat-reduced high quality beef production.