Physical map of the mitochondrial DNA from the phycomycete Allomyces macrogynus including the position of the ribosomal RNA genes and of an intervening sequence in the large rRNA gene

1983 ◽  
Vol 7 (5) ◽  
pp. 327-333 ◽  
Author(s):  
Bernhard Borkhardt ◽  
Hajo Delius
Keyword(s):  
Mitochondrial Dna ◽  
Ribosomal Rna ◽  
Physical Map ◽  
Ribosomal Rna Genes ◽  
Rrna Gene ◽  
Allomyces Macrogynus ◽  
Rna Genes

scholarly journals Evaluation and utility of mitochondrial ribosomal genes for molecular systematics of parasitic nematodes

2020 ◽  
Author(s):  
Abigail Hui En Chan ◽  
Kittipong Chaisiri ◽  
Serge Morand ◽  
Naowarat Saralamba ◽  
Urusa Thaenkham
Keyword(s):  
Genetic Marker ◽  
Genetic Markers ◽  
Molecular Systematics ◽  
Ribosomal Rna ◽  
Ribosomal Rna Genes ◽  
16S Ribosomal Rna ◽  
12S Rrna ◽  
Rrna Gene ◽  
12S Rrna Gene ◽  
Rna Genes

Abstract Background Molecular advances have accelerated our understanding of nematode systematics and taxonomy. However, comparative analyzes between various genetic markers have led to discrepancies in nematode phylogenies. This study aimed to evaluate the suitability of using mitochondrial 12S and 16S ribosomal RNA genes for nematode molecular systematics. Methods To study the suitability of mitochondrial 12S and 16S ribosomal RNA genes as genetic markers for nematode molecular systematics, we compared them with the other commonly used genetic markers, nuclear internal transcribed spacer 1 and 2 regions, nuclear 18S and 28S ribosomal RNA genes, and mitochondrial cytochrome c oxidase subunit 1 gene. After that, phylum-wide primers for mitochondrial 12S and 16S ribosomal RNA genes were designed, and parasitic nematodes of humans and animals from 75 taxa with 21 representative species were inferred through phylogenetic analyzes. Phylogenetic analyzes were carried out using maximum likelihood and Bayesian inference algorithms. Results The phylogenetic relationships of nematodes based on the mitochondrial 12S rRNA gene supported the monophyly of nematodes in clades I, IV, and V, reinforcing the potential of this gene as a genetic marker for nematode systematics. In contrast, the mitochondrial 16S rRNA gene only supported the monophyly of clades I and V, providing evidence that the 12S rRNA gene is more suitable for nematode molecular systematics. In this study, subclades of clade III containing various nematode families were not monophyletic when the 16S or 12S rRNA gene was used as the genetic marker. This is similar to the phylogenetic relationship revealed by previous studies using whole mitochondrial genomes as genetic markers. Conclusions This study supports the use of the 12S rRNA gene as a genetic marker for studying the molecular systematics of nematodes to understand intra-phyla relationships. Phylum-wide primers for nematodes using mitochondrial ribosomal genes were prepared, which may enhance future studies. Furthermore, sufficient genetic variation in the mitochondrial 12S and 16S rRNA genes between species also allowed for accurate taxonomy to species level, revealing the potential of these two genes as genetic markers for DNA barcoding.

Basonuclin is associated with the ribosomal RNA genes on human keratinocyte mitotic chromosomes

1999 ◽  
Vol 112 (18) ◽  
pp. 3039-3047 ◽  
Author(s):  
H. Tseng ◽  
J.A. Biegel ◽  
R.S. Brown
Keyword(s):  
Ribosomal Rna ◽  
Zinc Fingers ◽  
Hair Follicles ◽  
Ribosomal Rna Genes ◽  
Rrna Genes ◽  
Control Element ◽  
Rrna Gene ◽  
Metaphase Chromosomes ◽  
Acrocentric Chromosomes ◽  
Rna Genes

Basonuclin is a zinc finger protein mainly expressed in keratinocytes of the basal layer of epidermis and the outer root sheath of hair follicles. It is also found in abundance in the germ cells of testis and ovary. In cultured keratinocytes, basonuclin is associated with chromatin in all phases of the cell cycle, including mitosis. By immunocytochemical methods, we demonstrate here that in mitosis basonuclin is associated with the short arms of the acrocentric chromosomes and with other loci on many metaphase chromosomes of human keratinocytes. Using the evolutionarily highly conserved N-terminal pair of zinc fingers in an electrophoresis mobility shift assay, we demonstrate that the DNA target sequences of basonuclin on the acrocentric chromosomes are likely to be within the promoter region of the 45S rRNA gene transcription unit. DNase I footprinting shows that basonuclin zinc fingers interact with the upstream control element of this promoter, which is necessary for the high level of transcription of the rRNA genes. This result suggests that basonuclin may be a tissue-specific transcription factor for the ribosomal RNA genes.

scholarly journals Physical map of the seven ribosomal RNA genes of Escherichia coli

1979 ◽  
Vol 6 (5) ◽  
pp. 1817-1830 ◽  
Author(s):  
Imre Boros ◽  
Antal Kiss ◽  
Phá Venetianer
Keyword(s):  
Escherichia Coli ◽  
Ribosomal Rna ◽  
Physical Map ◽  
Ribosomal Rna Genes ◽  
Rna Genes
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