Recombinant bacteria secreting the transmembrane-truncated region of white spot syndrome virus （WSSV） envelope protein VP28 named DhpVB were constructed, using live Escherichia coli as a deliverer and a con- stituti...Recombinant bacteria secreting the transmembrane-truncated region of white spot syndrome virus （WSSV） envelope protein VP28 named DhpVB were constructed, using live Escherichia coli as a deliverer and a con- stitutive secretory expression plasmid as the expression vector. With the ability to deliver recombinant pro- tein products outside, DhpVB could make VP28 directly interact with the shrimp when injected into shrim- p. In order to test the protection potential, live DhpVB were injected into the marine shrimp Exopalamon carincauda Holthuis for three times and WSSV challenge was performed twice simultaneously at the last two injections of the bacteria. The results showed that DhpVB displayed statistically significant advantage over bacteria without VP28 after the second challenge with an average RI （Resistance index） of 0.67±0.08, compared with 0.41±0.09 of bacteria without VP28 （P 〈0.05）. The data suggested that a quasi-immune response may exist in E. carincauda and live bacteria carrying VP28 could enhance the shrimp resistance against WSSV.展开更多
A new member of antimicrobial protein genes of the Crustin family was cloned from haemocytes of the Chinese shrimp Fennero- penaeus chinensis by 3 ′and 5′ RACE. The full-length cDNA of Crustin-like gene contains a 3...A new member of antimicrobial protein genes of the Crustin family was cloned from haemocytes of the Chinese shrimp Fennero- penaeus chinensis by 3 ′and 5′ RACE. The full-length cDNA of Crustin-like gene contains a 390 bp open reading frame, encoding 130 amino acids. The deduced peptide contains a putative signal peptide of 17 amino acids and mature peptide of 113 amino acids. The molecular mass of the deduced mature peptide is 12. 3 ku. It is highly cationic with a theoretical isoelectric point of 8.5. The deduced amino acids sequence of this Crustin showed high homology with those of Penaeus （ Litopenaeus ） setferus. Northern blotting showed that the cloned Crustin gene was mainly expressed in haemocytes, gill, intestine, and RNA in situ hybridization indicated that the Crustin gene was constitutively expressed exclusively in haemocytes of these tissues. Capillary elec- trophoresis RT-PCR analysis showed that Crustin was up-regulated dramatically from 12 to 48 h after a brief decrease of mRNA during first 6 h in response to microbe infection. The level of Crustin mRNA began to restore at 72 h post-challenge. This indicated that Crustin gene might play an important role when shrimps are infected by bacterial pathogen.展开更多
基金The National Basic Research Program of China (973 Program) under contract No. 2012CB114403General Program of National Natural Science Foundation of China to Dr. Fuhua Li under contract No. 31072203+1 种基金National Hightech Research and Development Program under contract Nos 2012AA10A404 and 2012AA092205China Agriculture Research System under contract No. CARS-47
文摘Recombinant bacteria secreting the transmembrane-truncated region of white spot syndrome virus （WSSV） envelope protein VP28 named DhpVB were constructed, using live Escherichia coli as a deliverer and a con- stitutive secretory expression plasmid as the expression vector. With the ability to deliver recombinant pro- tein products outside, DhpVB could make VP28 directly interact with the shrimp when injected into shrim- p. In order to test the protection potential, live DhpVB were injected into the marine shrimp Exopalamon carincauda Holthuis for three times and WSSV challenge was performed twice simultaneously at the last two injections of the bacteria. The results showed that DhpVB displayed statistically significant advantage over bacteria without VP28 after the second challenge with an average RI （Resistance index） of 0.67±0.08, compared with 0.41±0.09 of bacteria without VP28 （P 〈0.05）. The data suggested that a quasi-immune response may exist in E. carincauda and live bacteria carrying VP28 could enhance the shrimp resistance against WSSV.
基金The Major State Basic Research Development Program of China under contract No2006CB101804the Natural Science Foundationof Hebei Province under contract NoC2008000596
文摘A new member of antimicrobial protein genes of the Crustin family was cloned from haemocytes of the Chinese shrimp Fennero- penaeus chinensis by 3 ′and 5′ RACE. The full-length cDNA of Crustin-like gene contains a 390 bp open reading frame, encoding 130 amino acids. The deduced peptide contains a putative signal peptide of 17 amino acids and mature peptide of 113 amino acids. The molecular mass of the deduced mature peptide is 12. 3 ku. It is highly cationic with a theoretical isoelectric point of 8.5. The deduced amino acids sequence of this Crustin showed high homology with those of Penaeus （ Litopenaeus ） setferus. Northern blotting showed that the cloned Crustin gene was mainly expressed in haemocytes, gill, intestine, and RNA in situ hybridization indicated that the Crustin gene was constitutively expressed exclusively in haemocytes of these tissues. Capillary elec- trophoresis RT-PCR analysis showed that Crustin was up-regulated dramatically from 12 to 48 h after a brief decrease of mRNA during first 6 h in response to microbe infection. The level of Crustin mRNA began to restore at 72 h post-challenge. This indicated that Crustin gene might play an important role when shrimps are infected by bacterial pathogen.
