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Bacteria of the family Chlamydiaceae are obligate intracellular pathogens of human and animals. Chlamydophila pecorum is associated with different pathological conditions in ruminants, swine and koala. To characterize a coding tandem repeat (CTR) identified at the 3' end of incA gene of C. pecorum, 51 strains of different chlamydial species were examined. The CTR were observed in 18 of 18 tested C. pecorum isolates including symptomatic and asymptomatic animals from diverse geographical origins. The CTR were also found in two strains of C. abortus respectively isolated from faeces from a healthy ewe and from a goat belonging to asymptomatic herds, but were absent in C. abortus strains isolated from clinical disease specimens, and in tested strains of C. psittaci, C. caviae, C. felis and C. trachomatis. The number of CTR repeats is variable and encode several motifs that are rich in alanine and proline. The CTR-derived variable structure of incA, which encode the Chlamydiaceae-specific type III secreted inclusion membrane protein, IncA, may be involved in the adaptation of C. pecorum to its environment by allowing it to persist in the host cell. 相似文献
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James M. Myers William K. Hershberger Robert N. Iwamoto 《Journal of the World Aquaculture Society》1986,17(1-4):1-7
The induction of tetraploidy was attempted in three intraspecies crosses (autotetraploid) of sal-monid: chinook salmon ( Oncorhynchus tshawytscha ), coho salmon ( O. kisutch ) and rainbow trout ( Salmo gairdneri ), and in the interspecies hybrid (allotetraploid) coho × Atlantic salmon ( Salmo salar ).
Pressure treatments of 6.2 × 104 kPa (9,000 psi) were applied for six minutes at intervals from 50% of the time to cleavage to beyond first cleavage. Analysis of eyed stage embryos via flow cytometry indicated two periods of tetraploid induction existed corresponding to 55–75% and 100–110% of the first cleavage interval (FCI).
The effects of different pressures and the times of application were analyzed in a study with rainbow trout. Treatments of 4.8 × 104 kPa (7,000 psi) for eight minutes, and 5.5 and 6.2 × 104 kPa (8,000 and 9,000 psi) for four minutes, were applied at 65, 78, and 100% FCI. Tetraploids were found in the 5.5 and 6.2 × 104 kPa group treatments only when applied at 65% FCI.
The results indicate that, while tetraploidy is inducible in salmonids, further experimentation is necessary to discern the appropriate time and treatment for optimal tetraploid induction in each species. 相似文献
Pressure treatments of 6.2 × 10
The effects of different pressures and the times of application were analyzed in a study with rainbow trout. Treatments of 4.8 × 10
The results indicate that, while tetraploidy is inducible in salmonids, further experimentation is necessary to discern the appropriate time and treatment for optimal tetraploid induction in each species. 相似文献
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Chicken interleukin 2 (IL-2) activity was partially purified from conditioned medium produced by culturing chicken splenic lymphocytes in the presence of concanavalin A. The purification procedure included sequential steps of gel filtration chromatography, reverse-phase high-pressure liquid chromatography, and phenyl-sepharose chromatography. Two peaks of IL-2 activity with apparent mol. wt. ranges of 36-39 kD and 17.5-25 kD were eluted from the Sephadex G100 gel filtration column. An increase in IL-2 spec. act. from 14 U mg-1 to between 2000 and 20,000 U mg-1 was obtained for the Sephadex G100 column peaks when subjected to the subsequent steps of the purification procedure. Alkylative reduction of the higher mol. wt. Sephadex G100 column peak (followed by re-chromatography with Sephadex G100), resulted in generation of the lower (17.5 kD) mol. wt. peak, indicating that chicken IL-2 is capable of either dimerizing or forming aggregates with other proteins. Elution of the lower mol. wt. IL-2 activity from a non-reducing sodium dodecyl sulfate-polyacrylamide gel demonstrated an apparent mol. wt. for chicken IL-2 of 20 kD, which confirmed the range of 17.5-25 kD seen with gel filtration. 相似文献
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Colostral and milk antibody titers in cows vaccinated with a modified live-rotavirus-coronavirus vaccine 总被引:4,自引:0,他引:4
Colostral and milk whey rotavirus (RV) and coronavirus (CV) antibody titers stimulated in 15 beef heifers by vaccination with a modified live-RV-CV vaccine were compared with titers in 15 nonvaccinated heifers. Geometric mean antibody titers to RV in colostral and 3-day milk whey from vaccinated heifers were 2,807 and 92, respectively, and in control heifers were 1,613 and 71, respectively. Geometric mean antibody titers to CV in colostral and 3-day milk whey of vaccinated heifers were 877 and 13, respectively, compared with titers were 877 and 13, respectively, compared with titers in nonvaccinated heifers of 731 and 7, respectively. Differences in antibody titers between vaccinated and nonvaccinated heifers were not significantly different. 相似文献
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