ABSTRACT
Spermatogonial stem cells [SSCs] are the only stem cells in adults that can transfer genetic information to the future generations. Considering the fact that a single SSC gives rise to a vast number of spermatozoa, genetic manipulation of these cells is a potential novel technology with feasible application to various animal species. The aim of this study was to evaluate enhanced green fluorescent protein [EGFP] gene transfection into bovine SSCs via liposome carrier and assess the best incubation day in uptake exogenous gene by SSCs. Transfection efficiency of EGFP gene with lipofectamine 2000 was determined in days following each three day of transfection [day 4, 6 and 8 of the culture] by fluorescent microscope. Results showed that the transfected cells through lipofection increased significantly [P<0.05] in each three days of transfection in comparison with those of the control groups. The transfected SSCs were higher in comparison with those of the free exogenous gene carrier groups [P<0.05]. In comparison with these three days, the rate of infected cells was higher when transfection proceeds at day four. It was concluded that lipofectamine can be used safely for direct loading exogenous DNA to SSCs particularly during the fourth day of culture
ABSTRACT
Contagious and environmental bacteria are current causes of mastitis and Bulk Tank Bacteria Count [BTBC]. Beside other hygienic procedures related to controlling mastitis, Post-Milking Teat Dipping [PMTD] with a suitable teat antisepsis has a special place and can play an important role in the kind of herd mastitis and decreasing the Total Bacteria Count [TBC]. This study was performed to evaluate the efficiency of short-time changing of PMTD solution on count and kind of milk tank bacteria. This study was conducted in 2 large dairy farms that their current antisepsis was iodophor components in 4 periods around Tehran during March to August 2010. In each 4 periods after the last time that iodophor was used, milk transfer tank sample was collected and 3 tests include Bulk Tank Somatic Cell Count [BTSCC], milk quality tests and bacterial isolation were performed. Then, antisepsis was replaced with chlore components for at least 2 weeks. At the end, another milk tank sample was obtained and tests were done again. Sectional changing of iodophor with chlore components in all 4 periods, according to decreasing in TBC, Coliform count, preliminary incubation count, laboratory pasteurized count, Staphylococcus count and Streptococcus count caused increasing the quality of milk and decreasing the mastitis. Changing in post-milking teat dipping has positive effect on quality of raw milk