Molecular cloning and expression analysis of five GhRAXs in upland cotton (Gossypium hirsutum L.).

The formation of axillary meristems in leaf axils is a prerequisite for the development of lateral shoots, which largely contribute to plant architecture. Several transcription factor-encoding genes, including CUC3, RAX, LAS, LOF1, and ROX, have been cloned by screening for axillary meristem mutants in Arabidopsis thaliana. These genes will facilitate our understanding of the mechanisms underlying axillary meristem development. In this study, we report the cloning of five genes from cotton (Gossypium hirsutum L.) that are orthologous to A. thaliana REGULATORS OFAXILLARY MERISTEMS (RAX) and tomato Blind (Bl), and they are designated GhRAX1, 2, 3, 4, and 5. Sequence analyses indicated that all five genes shared conserved protein domains with RAX and Bl. Phylogenetic analyses of protein sequences revealed that GhRAX2/3/4 were close to RAX1, whereas GhRAX1 and GhRAX5 were close to RAX3. Expression patterns of these genes in different tissues were also analyzed using real-time PCR.

Molecular cloning and expression analysis of GhLOF genes in upland cotton (Gossypium hirsutum L.).

Shoot branching, i.e., the timing and position of shoot growth, determines to a large extend the pattern of plant architecture, and is the result of the integration of a plant's genetic background and environmental cues. Many genes that are involved in the formation and outgrowth of axillary buds have been cloned, but the exact mechanism is still unclear. Branching pattern is an important agronomic trait in many crops, including cotton. In the present study, we cloned four genes from cotton, and designated them as GhLOF1/2/3/4. Sequence analysis revealed that all four genes shared conserved protein domains with LATERAL ORGAN FUSION (LOF) from Arabidopsis and TRIFOLIATE (Tf) from tomato. Phylogenetic analysis revealed that GhLOF3 and GhLOF4 were close to Tf because of their similar expression patterns, whereas GhLOF1 and GhLOF2 were differentially expressed.

Acute viral hepatitis in Hanoi, Viet Nam.

A study of acute hepatitis was conducted in Hanoi, Viet Nam, from January 1993 to February 1995; 188 sera from clinical hepatitis cases were screened by enzyme-linked immunosorbent assay for immunoglobulin (Ig) M anti-hepatitis A virus (HAV), IgM anti-hepatitis B core antigen (HBc), IgG anti-hepatitis C virus (HCV), IgG anti-hepatitis E virus (HEV) and IgM anti-HEV. Additionally, 187 sera from control subjects, matched by age, sex and month of admission, with no recent history of hepatitis, were tested for comparative purposes. There was serological evidence of recent HAV (29%) and hepatitis B virus (24%) infection in 53% of cases (2 mixed infections), compared with 2% of controls. HCV infections were detected in 10% of cases (with no IgM anti-HAV or IgM anti-HBc) and in 1% of control sera. There was no significant difference in the proportion of IgG anti-HEV positive sera between cases (in the absence of IgM anti-HAV or IgM anti-HBc) (21%) and controls (14%); 3% of all case sera were IgM anti-HEV positive. Younger cases (< 20 years) were more likely to have recent HAV infections (41%) than those aged > or = 20 years (21%) (P < 0.01). In contrast, a higher percentage of adult cases had IgM anti-HBc, IgG anti-HCV and IgG anti-HEV (in the absence of recent HAV or HBV infection) than did children. No seasonal trend in hepatitis admissions was detected, nor an association between water-borne infections (HAV and HEV) and the warmer months. Hepatitis patients lived throughout Hanoi and surrounding areas, with no identifiable geographical clustering, regardless of serological marker.

Expression of fimbriae and host response in Branhamella catarrhalis respiratory infections.

Sputum during the acute exacerbation of chronic respiratory diseases were observed under the electron microscope, to determine the in vivo expression of surface structures of Branhamella catarrhalis (B. catarrhalis), the polymorphonuclear neutrophil (PMN) response to B. catarrhalis infections, and the composition of sputum. It was found that during infection fimbriae are expressed in B. catarrhalis. However, there were sparsely to densely fimbriated bacteria in each sputum sample. The length of the fimbriae were from 50 to 76 nm. In the sparsely fimbriated B. catarrhalis, external to the cell wall, a thin, granular, electron-dense layer was observed. Due to the presence of fimbriae, this layer was not seen in densely fimbriated B. catarrhalis. Blebs were also found in B. catarrhalis. PMNs were found to phagocytose both B. catarrhalis and debris. Evidence was found that debris were formed mainly by the destruction of PMNs. Bacteria as well as debris were phagocytosed by PMNs.

Neutrophil response to Pseudomonas aeruginosa in respiratory infection.

Sputum from patients with acute exacerbation of respiratory infection by Pseudomonas aeruginosa was observed under the electron microscope. External to the cell wall of P. aeruginosa a granular, electron-dense material was observed which is suggestive of capsule. It is supposed that stabilization of capsule occurred by the host antibody, which was produced due to chronic infection by P. aeruginosa. Mucoid type of microcolonies were observed with a fibrous matrix of exopolysaccharide. Other types of microcolonies were surrounded by granular substances or fine fibers. Neutrophil was found to be partially surrounding the microcolony in an attempt to defense. Debris was formed mainly by the destruction of the neutrophil. Most neutrophils were found full of phagocytosed debris; in contrast only a few neutrophils were found to have phagocytosed P. aeruginosa. This study concludes that instead of phagocytosing bacteria, neutrophil phagocytosed debris and bacteria were not completely eradicated. Therefore, this might be one of the factors in the pathogenesis of respiratory infection and persistent colonization by P. aeruginosa.

Neutrophil response to nontypable Haemophilus influenzae in respiratory infections.

Sputa from patients with respiratory infections by nontypable Haemophilus influenzae (H. influenzae) were investigated by electron microscopy. The cell wall of H. influenzae appeared wavy and nonwavy. In the cell wall the peptidoglycan layer was ill-defined. These patients had adequate IgG response in the serum against H. influenzae. However neither capsule nor fimbriae were found. Different stages of phagocytosis and destruction of the bacteria by polymorphonuclear neutrophils (PMN) were observed. PMNs were also found to phagocytose the debris. Evidences were found that the debris is formed mainly by the destruction of polymorphonuclear neutrophil. Extracellular lysosomes were also observed, which may have a role in destruction of both bacteria and host tissue. It was concluded that nontypable H. influenzae are nonfimbriated and noncapsulated during infection. Debris are the end product of PMN destruction, and phagocytosis of debris by PMNs has a role in the pathogenesis of chronic respiratory diseases.