OBJECTIVE: To construct a plant effective expression vector driven by a fruit specific promoter for the expression of hepatitis B virus surface antigen (HBsAg), to further improve the expression of exogenous gene in plant, and to prepare for the development of an effective anti-hepatitis vaccine. METHODS: Tomato fruit-specific promoters' gene 2A12 and E8 were respectively introduced to pBPFOmega7 to form pB2A12 and pBE8. The DNA fragment containing HBsAg-s gene from plasmid YEP-HBs was inserted respectively into pB2A12 and pBE8 to form pB2A12-HBs and pBE8-HBs. The fragment containing "p35S+2A12+Omega+HBsAg-s+Tnos" of the pB2A12-HBs was sub-cloned into plasmid pCAMBIA1301 to yield the reconstructed plant binary expression plasmid pCAM2A12-HBs, and the fragment containing "p35S+E8+Omega+HBsAg-s+Tnos" of the pBE8-HBs was sub-cloned into plasmid pCAMBIA1301 to yield the plasmid pCAME8-HBs. The inserted gene HBsAg and fruit-specific promoters in the reconstructed plant binary expression vectors were confirmed by sequencing. Then, pCAM2A12-HBs and pCAME8-HBs were directly introduced into Agrobacterium tumefaciens strain EHA105. RESULTS: Digestion with restriction enzymes proved that all recombinant vectors had the inserts with expected length of the target fragments, and the sequencing results were confirmed correct. CONCLUSION: In this study, plant expression vector containing HBsAg gene driven by fruit specific promoter and CaMV35s promoter was successfully constructed.

Objective To understand the cigarette consumption of Guangzhou residents and its influencing factors. Method The stratified random sampling was adopted and the selected families were visited by trained investigators with questionnaire from April to August in 2004. Results 27718 residents over 15 years old were investigated. The smoking rate was 22.7%, and 46.2% for male and 2.0% for female. The currently smoking rate was 19.9% (male 40.5% and female 1.6%). The currently smokers lighted up their first cigarette when they were 20 years old in median and their consumption were averagely 14.3 sticks everyday. 13.1% smokers tried to quit smoking. 9.4% people who once gave up cigarette picked it up again. The Logistic Stepwise Regression analysis showed sex (OR=0.022, 95%CI: 0.019~0.026), education (OR=0.697, 95%CI: 0.659~0.737), family income(OR=0.975, 95%CI: 0.955~0.995)and alcohol drinking(OR=2.687, 95%CI: 2.467~2.927)were found to be the influencing factors for individual smoking. Conclusion The resident smoking rate was lower in Guangzhou than that in Guangdong province or in China but it was still very higher. The most smokers were male and little of them quitted smoking. The tobacco control should be enhanced.

Postnatal heart maturation is the basis of normal cardiac function and provides critical insights into heart repair and regenerative medicine. While static snapshots of the maturing heart have provided much insight into its molecular signatures, few key events during postnatal cardiomyocyte maturation have been uncovered. Here, we report that cardiomyocytes (CMs) experience epigenetic and transcriptional decline of cardiac gene expression immediately after birth, leading to a transition state of CMs at postnatal day 7 (P7) that was essential for CM subtype specification during heart maturation. Large-scale single-cell analysis and genetic lineage tracing confirm the presence of transition state CMs at P7 bridging immature state and mature states. Silencing of key transcription factor JUN in P1-hearts significantly repressed CM transition, resulting in perturbed CM subtype proportions and reduced cardiac function in mature hearts. In addition, transplantation of P7-CMs into infarcted hearts exhibited cardiac repair potential superior to P1-CMs. Collectively, our data uncover CM state transition as a key event in postnatal heart maturation, which not only provides insights into molecular foundations of heart maturation, but also opens an avenue for manipulation of cardiomyocyte fate in disease and regenerative medicine.
Gene Expression Regulation ; Heart ; Myocytes, Cardiac/metabolism* ; Single-Cell Analysis ; Transcription Factors/metabolism*