ABSTRACT
A highly conserved extended hairpin structure in the 3' external transcribed spacer (3' ETS) region of nascent eukaryotic rRNA transcripts is essential for the maturation of the large ribosomal subunit RNAs (5.8 S and 25 to 28 S rRNAs). Systematic changes were introduced into this structure by PCR-mediated mutagenesis and the mutant rDNAs were expressed in vivo to determine the structural features that are essential for rRNA maturation. Changes in the lower half of the stem or the large loop at the end had little or no effect on the maturation of either the 5.8 S or 25 S rRNA, but changes that disrupted secondary structure in the upper half of this stem had equal and dramatic effects on both RNAs. When the RNA stem was incubated with a cellular protein extract, gel retardation studies indicated that the stem forms a ribonucleoprotein complex, and a comparison with mutant RNA indicated that protein binding could be compromised by changes that were critical for rRNA maturation. Sequence comparisons with other spacer regions as well as snRNAs reveal some structural analogy, which, when taken together with the mutational studies, raise the possibility that this hairpin functions during RNA processing in a manner that may be analogous with that of free snRNPs.
Subject(s)
RNA Processing, Post-Transcriptional , RNA, Ribosomal/chemistry , RNA, Ribosomal/genetics , Schizosaccharomyces/genetics , Transcription, Genetic , Base Sequence , Deoxyribonucleases, Type II Site-Specific/genetics , Molecular Sequence Data , Mutagenesis , Nucleic Acid Conformation , Plasmids/genetics , RNA, Fungal/chemistry , RNA, Fungal/genetics , RNA, Ribosomal, 5.8S/chemistry , RNA, Ribosomal, 5.8S/geneticsABSTRACT
This article examines the shift in emphasis in community care provision and how this will affect the role of community nurses and contribute to the need for new community nursing skills.
Subject(s)
Community Health Nursing/education , Community Health Services/organization & administration , Education, Nursing, Continuing , Clinical Competence , Humans , Organizational InnovationSubject(s)
Curriculum , Education, Nursing , Clinical Competence , England , Humans , Pilot ProjectsABSTRACT
A simple filter paper spot test is described for identifying adult Aedes aegypti resistant to malathion as a result of raised esterase levels. The method is compared with established polyacrylamide gel (PAG) electrophoresis techniques for determining esterase-6 activity, and its applicability as a field test is discussed.
Subject(s)
Aedes/enzymology , Esterases/metabolism , Malathion , Animals , Body Weight/drug effects , Electrophoresis, Polyacrylamide Gel , Female , Insecticide Resistance , Malathion/pharmacology , MaleSubject(s)
Aedes/enzymology , Carboxylic Ester Hydrolases/metabolism , Malathion , Animals , Carboxylesterase , Female , Insecticide Resistance , MaleSubject(s)
Aedes/genetics , Esterases/genetics , Genetic Linkage , Genetic Markers , Aedes/enzymology , Alleles , Animals , Chromosome Mapping , Female , MaleABSTRACT
The DDT resistance gene RDDT1, and the dieldrin resistance gene Rd1 have been mapped on linkage group II with respect to visible markers, in the mosquito Aedes argypti L. The best interpretation of the data gives the order wa - Rdl - ds RDDT1 - s - y but was - Rdl -ds - y - s - RDDT1 is also possible. h is very loosely linked with RDDT1. The length of the linkage group has been considerably extended from previous studies.
Subject(s)
Aedes , DDT/pharmacology , Dieldrin/pharmacology , Drug Resistance , Genes , Genetic Linkage , Aedes/drug effects , Animals , Chromosome Mapping , Crosses, Genetic , Female , Genotype , Larva/drug effects , Male , Recombination, GeneticABSTRACT
The gene RDDT2, which gives resistance to DDT in the imago of Aedes aegypti L. has been mapped on linkage group III with respect to six visible markers. The best interpretation of the order of the genes is:- blp - blt - co - fz - wi -RDDT2 - min, but the order blp - blt - co - fz -RDDT2 - wi - min is also possible.
