RESUMO
Sequences coding for the bean seed protein phaseolin were inserted into transferred DNA regions of tumor-inducing plasmids. Constructions were devised in which the coding region of phaseolin was fused in the correct reading frame with the coding region of octopine synthase and placed under the transcriptional control of the octopine synthase promoter. Other plasmids were prepared to permit expression of the phaseolin-encoding sequences from the flanking phaseolin promoter region. The RNA transcribed in sunflower cells transformed with these constructions was characterized by hybridization procedures, SI nuclease mapping, and by translation in vitro of extracted RNA. These tests showed that the genomic intervening sequences were correctly excised. Immunoreactive phaseolin polypeptides were detected by enzyme-linked immunosorbent assay and by antibody hybridization to electrophoretically separated protein extracts of sunflower tissues isolated from crown gall tumors and of transformed sunflower cells grown in tissue culture. These results demonstrate the expression of a plant gene after transfer to a taxonomically distinct botanical family.
RESUMO
We have constructed a hybrid chromosome composed of the genome of wild-type fd (a filamentous, male-specific bacteriophage) and a segment of transposon Tn10 coding for tetracycline resistance but not including the Tn10 insertion sequences. The hybrid phage infects male E. coli, thereby transducing the infected cells to tetracycline resistance. The phage DNA can also be propagated in F- cells after transfection. This new phage, fd-tet, may be used as a cloning vector to produce large quantities of cloned DNA in single-stranded form. Its usefulness has been demonstrated by cloning of a fragment from bacteriophage lambda. Some unexpected sequence alterations have been identified in lambda cloning experiments.
Assuntos
Colífagos/genética , DNA Recombinante , Escherichia coli/genética , Vetores Genéticos , Elementos de DNA Transponíveis , Fatores R , Tetraciclina/farmacologia , Transdução GenéticaRESUMO
A study was carried out in two villages in a rural area of Andhra Pradesh, India, 150 kilometres south of the state capital, Hyderabad. Ninety-eight women and sixty-two men, age range 15-70 years, were interviewed and examined. Information gathered included socio-economic data, distance travelled outside the village and previous access to health care. Data were recorded on periodontal status using CPITN and full periodontal charting. Comparisons were made between male and female subjects for travel outwith the village, attendance at medical and dental health facilities, tooth cleaning methods and materials and prevalence of periodontal disease. There was a high prevalence of chronic inflammatory periodontal disease in this population, and most of this was untreated. In view of the difficulties in access to health care, it would be prudent to offer good preventive oral health care within the rural community.