Ribosomal Cistrons
Mostrando 1-12 de 64 artigos, teses e dissertações.
-
1. Chromosome diversity in Buthidae and Chactidae scorpions from Brazilian fauna: Diploid number and distribution of repetitive DNA sequences
Abstract In this work, we analyzed cytogenetically eight Chactidae and Buthidae, including the localization of repetitive DNA sequences. The chactids possess monocentric chromosomes and the highest diploid numbers (2n=50 in Brotheas amazonicus, 2n=36 in Chactopsis amazonica, 2n=30 in Neochactas sp.) when compared with buthids (2n=10 in Tityus bahiensis, 2n=1
Genetics and Molecular Biology. Publicado em: 2023
-
2. Cytogenetic markers as tools in delimiting species of the highly diverse Neotropical fish Bryconamericus (Characiformes: Characidae)
RESUMO Bryconamericus é um grupo altamente diverso de caracídeos, sendo a citogenética uma valiosa ferramenta para a delimitação de espécies. Bryconamericus aff. iheringii (Alto Uruguai/Baixo Paraná), B. coeruleus (Alto Paraná), B. cf. ecai e B. cf. eigenmanni (Alto Uruguai) foram estudados citogeneticamente, e apresentaram 2n=52 cromossomos, com var
Neotrop. ichthyol.. Publicado em: 23/09/2019
-
3. Cytogenetic analysis of Astylus antis (Perty, 1830) (Coleoptera, Melyridae): Karyotype, heterochromatin and location of ribosomal genes
Cytogenetic analysis of Astylus antis using mitotic and meiotic cells was performed to characterize the haploid and diploid numbers, sex determination system, chromosome morphology, constitutive heterochromatin distribution pattern and chromosomes carrying nucleolus organizer regions (NORs). Analysis of spermatogonial metaphase cells revealed the diploid num
Genetics and Molecular Biology. Publicado em: 07/06/2010
-
4. Differential transcription of ribosomal cistrons denoting nucleolar dominance in hybrids of Drosophila mulleri and Drosophila navojoa (mulleri complex, Repleta group)
The fruit flies Drosophila mulleri and Drosophila navojoa are included in the mulleri complex of the mulleri subgroup and Repleta group. Although there is no demonstration that interspecific crosses between them occur in nature, they intercross in the laboratory in both cross directions. Previous data have shown the occurrence of nucleolar dominance in inter
Genetics and Molecular Biology. Publicado em: 2007
-
5. Cariótipo molecular: uma ferramenta para o estudo analítico e evolutivo do genoma de Trypanosoma cruzi / Molecular karyotype: a tool for the analytical and evolutionary study of Trypanosoma cruzi genome.
Different typing methods and phylogenetic inference based on the nucleotide sequence of few nuclear genes indicate that Trypanosoma cruzi can be divided into two major groups named as T. cruzi I and T. cruzi II. Additional subgroups of isolates have been described, such as group of rDNA 1/2 and zymodeme 3 (Z3), whose phylogenetic relationships with the T. cr
Publicado em: 2005
-
6. Further Studies on the Ribosomal RNA Cistrons of SCIARA COPROPHILA (Diptera)
Additional experiments with homologous as well as heterologous hybridization confirmed our previous finding in Sciara coprophila that XX females have nearly twice the number of ribosomal RNA cistrons as X0 males. A comparison between two different X' chromosomes revealed that only the one carrying the irradiation-induced Wavy mutation has a deletion of 70%
-
7. Distribution of Ribosomal Ribonucleic Acid Cistrons Among Yeast Chromosomes
High-molecular-weight deoxyribonucleic acid (DNA) of Saccharomyces carls bergensis has been fractionated by sucrose density gradient centrifugation. The main DNA fraction has an average molecular weight of about 500 × 106. A major fraction of the DNA molecules containing sequences homologous to ribosomal ribonucleic acid (RNA) sediments as material of this
-
8. Extragenic suppression of two ribosomal protein cistrons lying near the rif locus in Escherichia coli.
The experiments reported here involve temperature-sensitive mutations in two of five cistrons encoding 50S ribosomal proteins that lie near the rif locus in Escherichia coli. I selected spontaneous TS+ mutants able to grow at elevated temperatures in which the TS+ event takes place outside this tract of cistrons near rif. Six distinct classes of extragenic s
-
9. Chromosomal Location of Ribosomal Protein Cistrons Determined by Intergeneric Bacterial Mating
Intergeneric mating between Escherichia coli and Salmonella typhosa was used to locate at least three 30S ribosomal proteins near the streptomycin locus in the region of 54 to 66 min of the E. coli map. This procedure utilizes differences in the electrophoretic patterns of 30S ribosomal protein of the parents. The results show that cistrons for 30S proteins
-
10. Transcriptional Mapping: Functional Organization of the Ribosomal and Transfer Ribonucleic Acid Cistrons in the Bacillus subtilis Genome
The transcriptional mapping method developed previously has been used to investigate the functional organization of the ribosomal ribonucleic acid (rRNA) and transfer ribonucleic acid (tRNA) cistrons in the Bacillus subtilis genome. The sensitivities of the syntheses of these RNA species to actinomycin D indicated that (i) large polycistronic groupings of th
-
11. Morphology of Nucleolar Cistrons in a Plant Cell, Acetabularia mediterranea
The structural organization of transcriptionally active DNA that contains cistrons for precursor molecules of ribosomal RNA is described in positively stained spread preparations from nuclei and nucleoli isolated from the green alga, Acetabularia mediterranea Lmx. These nuclei contain large aggregates of nucleolar subunits in which fibril-covered regions, th
-
12. Transcriptional Organization of the Ribosomal RNA Cistrons in Escherichia Coli
The data presented support the hypothesis that 16S, 23S, and 5S ribosomal RNAs of Escherichia coli are transcribed in vivo from transcriptional units consisting of single cistrons for these species arranged in the order 16S-23S-5S, with transcription beginning at the 16S end.