[Objective] The study aimed to obtain attenuated strain of Haemophilus parasuis.[Method] Tn5 transposon technology was used to construct a library of mutants.Positive mutants were screened by kanamycin resistance.Fals...[Objective] The study aimed to obtain attenuated strain of Haemophilus parasuis.[Method] Tn5 transposon technology was used to construct a library of mutants.Positive mutants were screened by kanamycin resistance.False positive was identified by PCR and then removed.Mice were infected to detect the virulence of mutants.The bionomics of attenuated strains were detected,too.[Result] The attenuated mutants showed similar reproductive activity to that of wild strain.The virulence of mutants was still stable after 30 passages.[Conclusion] This study provided foundation for exploring the virulence factors and pathogenic mechanism of HPS.展开更多
The molecular basis of color polymorphism in the shells of the pearl oyster Pinctada fucata is largely unknown. We developed a red-shelled family line and used suppression subtractive hybridization （SSH） to screen f...The molecular basis of color polymorphism in the shells of the pearl oyster Pinctada fucata is largely unknown. We developed a red-shelled family line and used suppression subtractive hybridization （SSH） to screen for differentially expressed genes in red- and non-red-shelled pearl oysters. We constructed forward and reverse cDNA subtractive libraries consisting of 2 506 and 797 clones, respectively. Among 343 randomly selected clones in the forward library, 304 sequences were identified in GenBank using BLASTx and BLASTn. Of the 304 sequences, 13 showed no similarity to known sequences and 291 were matched with known genes of the pearl oyster, including shematrin-1, shematrin-2, shematrin-6, shematrin-7, nacrein, nacrein-like protein, aspein for shell matrix protein, glycine-rich protein, mantle gene 5, 28S, EST00031, EST00036, 16S, and COl. In the reverse library, 7 clones were sequenced and analyzed by BLAST. Two sequences shared similarity with EST00036 from the P. fucata subtraction cDNA library, four with the P. fucata mitochondrial gene for 16S rRNA and 1 with P. fucata shematrin-2. We evaluated the expression of 12 genes from the forward library using RT PCR. Two sequences matched with 16S and CO1 so were considered to be false positives. The remaining 10 sequences were differentially expression in the red-shelled pearl oysters. Our results suggest that differential expression of these genes may be related to color variation in the red-shelled family line of the pearl oyster.展开更多
基金Supported by National High Technology Research and Development Program of China(2006AA10A206)National Natural Science Foundation of China(31001072)the Fund of Beijing Academy of Agriculture and Forestry Sciences for Young Scholars(QNJJ201012)~~
文摘[Objective] The study aimed to obtain attenuated strain of Haemophilus parasuis.[Method] Tn5 transposon technology was used to construct a library of mutants.Positive mutants were screened by kanamycin resistance.False positive was identified by PCR and then removed.Mice were infected to detect the virulence of mutants.The bionomics of attenuated strains were detected,too.[Result] The attenuated mutants showed similar reproductive activity to that of wild strain.The virulence of mutants was still stable after 30 passages.[Conclusion] This study provided foundation for exploring the virulence factors and pathogenic mechanism of HPS.
基金Supported by National High Technology Research and Development Program of China (863 Program) (No. 2006AA10A409)the Knowledge Innovation Program of the South China Sea Institute of Oceanology, Chinese Academy of Sciences (No. SQ200906)+2 种基金the Science and Technology Program of Guangdong Province (No. 2008A020100004)the National Key Technology Research and Development Program (No. 2007BAD29B01-8)the Key Plan for Marine Development of Guangdong Province (No. A200708C01)
文摘The molecular basis of color polymorphism in the shells of the pearl oyster Pinctada fucata is largely unknown. We developed a red-shelled family line and used suppression subtractive hybridization （SSH） to screen for differentially expressed genes in red- and non-red-shelled pearl oysters. We constructed forward and reverse cDNA subtractive libraries consisting of 2 506 and 797 clones, respectively. Among 343 randomly selected clones in the forward library, 304 sequences were identified in GenBank using BLASTx and BLASTn. Of the 304 sequences, 13 showed no similarity to known sequences and 291 were matched with known genes of the pearl oyster, including shematrin-1, shematrin-2, shematrin-6, shematrin-7, nacrein, nacrein-like protein, aspein for shell matrix protein, glycine-rich protein, mantle gene 5, 28S, EST00031, EST00036, 16S, and COl. In the reverse library, 7 clones were sequenced and analyzed by BLAST. Two sequences shared similarity with EST00036 from the P. fucata subtraction cDNA library, four with the P. fucata mitochondrial gene for 16S rRNA and 1 with P. fucata shematrin-2. We evaluated the expression of 12 genes from the forward library using RT PCR. Two sequences matched with 16S and CO1 so were considered to be false positives. The remaining 10 sequences were differentially expression in the red-shelled pearl oysters. Our results suggest that differential expression of these genes may be related to color variation in the red-shelled family line of the pearl oyster.
