Objective To study the location and the expression of nerve growth factor(NGF)in mouse testes at different developmental stages.Methods The testes were taken out from mice at different developmental stages,respectively.Parts of the testis tissue were used to extract total RNA and real-time PCR was used to detect the expression of NGF.The rest tissues were fixed and embedded in paraffin.SABC immunohistochemical staining was used to observe the location of NGF in the testes. Results Reat-time PCR results showed that NGF mRNA could be detected in the testes of mouse at postnatal 1 st week and its expression level increased with the development,and reached the highest point at 3rd week.After 5 weeks it lowered down to a stable level.Immunohistochemistry showed that NGF expressed in the mouse testes at all developmental stages.At postnatal 1 st week immunopositive reaction of NGF was detected mainly in sustentacular cells and the spermatogonia also showed positive staining.NGF positive staining in the testes was observed in interstitial cells,spermatogenetic cells,sustentacular cells and Leydig cells at 3rd week.After the postnatal 5th week,NGF-positive immunostaining was also detected in intersitial cells and spermatogenetic cells,but the intensity of reaction was weaker than that at 1 st and 3rd weeks.Conclusion The expression levels of NGF in mouse testes show regular changes and the expression profile and location of NGF in the testes are different at different developmental stages.

The protective efficacy of DNA plasmids encoding avian infectious bronchitis virus (IBV) S1, N, or M protein was investigated in chickens. Chickens were inoculated monovalently (with plasmid pVAX1-16S1, pVAX1-16M, or pVAX1-16N alone) or multivalently (combination of the three different plasmids, pVAX1-16S1/M/N). A prime-boost immunization protocol against IBV was developed. Chickens were immunized with the multivalent DNA vaccine twice and then boosted with an inactivated vaccine once. Antibody titers of the chickens immunized with pVAX1-16S1/M/N were much higher than those of the monovalent groups (p < 0.01). A protective rate up to 90% was observed in the pVAX1-16S1/M/N group. The serum antibody titers in the prime-boost birds were significantly higher than those of the multivalent DNA vaccine group (p < 0.01) but not significantly different compared to the inactivated vaccine group at 49 days of age. Additionally, the prime-boost group also showed the highest level of IBV-specific cellular proliferation compared to the monovalent groups (p < 0.01) but no significant difference was found compared to the multivalent DNA vaccine group, and the prime-boost group completely protected from followed viral challenge.
Aging ; Animals ; Antibodies, Viral/blood ; Cell Proliferation ; Chickens ; Coronavirus Infections/prevention & control/*veterinary/virology ; Immunization, Secondary/veterinary ; Infectious bronchitis virus/*immunology ; Poultry Diseases/*prevention & control/virology ; T-Lymphocyte Subsets/cytology/physiology ; Vaccines, DNA/immunology ; Vaccines, Inactivated/immunology ; Viral Vaccines/*immunology