Physical localization of rRNA genes by fluorescence in situ hybridization (FISH) and analysis of spacer length variants of 45S rRNA (slvs) genes in some species of genus Sesbania

2014 ◽  
Vol 300 (8) ◽  
pp. 1793-1802
Author(s):  
Sundip Kumar ◽  
Bernd Friebe ◽  
Bikram S. Gill
2015 ◽  
Vol 9 (2) ◽  
pp. 145-160 ◽  
Author(s):  
Katrijn Van Laere ◽  
Prabhu Shankar Lakshmanan ◽  
Tom Eeckhaut ◽  
Johan Van Huylenbroeck ◽  
Erik Van Bockstaele ◽  
...  

1999 ◽  
Vol 77 (3) ◽  
pp. 389-393 ◽  
Author(s):  
Jin-Feng Chen ◽  
Jack E Staub ◽  
Jeffrey W Adelberg ◽  
Jiming Jiang

The chromosomal locations of the genes coding for the 18S-5.8S-26S rRNA was investigated in Cucumis species using fluorescence in situ hybridization. Cucumber (Cucumis sativus L., 2n = 2x = 14) possesses four pairs of rDNA loci that were mapped to chromosomes 1C, 2C, 4C, and 7C. The distinctive hybridization sites of the 18S-5.8S-26S rRNA genes provide several useful cytogenetic markers for identification of chromosomes in C. sativus. The 18S-5.8S-26S rDNA genes have also been detected on two chromosome pairs, one major and one minor pair of loci, in melon (Cucumis melo L., 2n = 2x = 24) and on three pairs of Cucumis hystrix Chakr. chromosomes. The different number and pattern of rDNA sites is consistent with the hypothesis that considerable phylogenetic distance exists among these species.Key words: fluorescence in situ hybridization, 45S rRNA gene, cytogenetics, Cucumis sativus, Cucucmis melo, Cucumis hystrix.


1994 ◽  
Vol 66 (4) ◽  
pp. 246-249 ◽  
Author(s):  
Y. Matsuda ◽  
K. Moriwaki ◽  
V.M. Chapman ◽  
Y. Hoi-Sen ◽  
J. Akbarzadeh ◽  
...  

2006 ◽  
Vol 73 (1) ◽  
pp. 303-311 ◽  
Author(s):  
Christine M. Anderson ◽  
Margo G. Haygood

ABSTRACT Bacterial symbionts that resembled mollicutes were discovered in the marine bryozoan Watersipora arcuata in the 1980s. In this study, we used PCR and sequencing of 16S rRNA genes, specific fluorescence in situ hybridization, and phylogenetic analysis to determine that the bacterial symbionts of “W. subtorquata” and “W. arcuata” from several locations along the California coast are actually closely related α-Proteobacteria, not mollicutes. We propose the names “Candidatus Endowatersipora palomitas” and “Candidatus Endowatersipora rubus” for the symbionts of “W. subtorquata” and “W. arcuata,” respectively.


2000 ◽  
Vol 66 (12) ◽  
pp. 5116-5122 ◽  
Author(s):  
Matthew T. Cottrell ◽  
David L. Kirchman

ABSTRACT We determined the compositions of bacterioplankton communities in surface waters of coastal California using clone libraries of 16S rRNA genes and fluorescence in situ hybridization (FISH) in order to compare the community structures inferred from these two culture-independent approaches. The compositions of two clone libraries were quite similar to those of clone libraries of marine bacterioplankton examined by previous studies. Clones from γ-proteobacteria comprised ca. 28% of the libraries, while approximately 55% of the clones came from α-proteobacteria, which dominated the clone libraries. TheCytophaga-Flavobacter group and three others each comprised 10% or fewer of the clone libraries. The community composition determined by FISH differed substantially from the composition implied by the clone libraries. The Cytophaga-Flavobacter group dominated 8 of the 11 communities assayed by FISH, including the two communities assayed using clone libraries. On average only 10% of DAPI (4′,6′-diamidino-2-phenylindole)-stained bacteria were detected by FISH with a probe for α-proteobacteria, but 30% of DAPI-stained bacteria appeared to be in the Cytophaga-Flavobacter group as determined by FISH. α-Proteobacteria were greatly overrepresented in clone libraries compared to their relative abundance determined by FISH, while the Cytophaga-Flavobacter group was underrepresented in clone libraries. Our data show that theCytophaga-Flavobacter group can be a numerically dominant component of coastal marine bacterioplankton communities.


2000 ◽  
Vol 23 (1) ◽  
pp. 135-138 ◽  
Author(s):  
Adriane Pinto Wasko ◽  
Pedro Manoel Galetti Jr.

The present study provides data on the nucleolar organizer regions (NORs) of seven Brycon species based on mapping of the 18S rRNA genes by fluorescence in situ hybridization (FISH). Fluorescent signals were observed on the telomere of the long arm of two large submetacentric chromosomes, thus confirming the number and location of NORs previously revealed by other classical cytogenetic techniques. Although there were no inter- or intra-individual variations in the number and location of the 18S loci, NOR size polymorphism was observed between homologous chromosomes. The clustering and conservation of NORs in a single chromosome pair indicates a high level of NOR stability among species of the genus Brycon.


2008 ◽  
Vol 75 (3) ◽  
pp. 802-810 ◽  
Author(s):  
Jennifer Pratscher ◽  
Catrin Stichternoth ◽  
Katrin Fichtl ◽  
Karl-Heinz Schleifer ◽  
Gesche Braker

ABSTRACT Denitrification is an alternative type of anaerobic respiration in which nitrate is reduced to gaseous products via nitrite. The key step in this process is the reduction of nitrite to nitric oxide, which is catalyzed by two structurally different but functionally equivalent forms of nitrite reductase encoded by the nirK and nirS genes. Cultivation-independent studies based on these functional marker genes showed that in the environment there was a dominance of organisms with nirK and nirS genes presumably derived from organisms that have not been cultured yet. However, the phylogenetic affiliation of these organisms has not been resolved since the ability to denitrify is widespread in phylogenetically unrelated organisms. To unravel the phylogeny of the organisms from which the nitrite reductase (nirK) genes originated, one option is to use a special variant of whole-cell hybridization termed recognition of individual genes-fluorescence in situ hybridization (RING-FISH). In RING-FISH a multiply labeled transcript polynucleotide probe is used to detect a single gene on the bacterial chromosome during FISH. Here, RING-FISH was used with laboratory cultures and environmental samples, such as activated sludge. Furthermore, probe-based cell sorting using magnetic beads could also be carried out with mixtures of pure cultures, which led to effective depletion of the nirK-negative organism but capture of the nirK-positive organism, which was demonstrated by terminal restriction fragment length polymorphism analysis based on 16S rRNA genes. The results indicate that RING-FISH coupled with probe-based cell sorting could be used with environmental samples, which could provide a means for phylogenetic classification of nirK-type denitrifiers. Thus, the results of RING-FISH could increase our understanding of the phylogeny and function of denitrifying microorganisms in the environment.


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