A supernumerary chromosome segment in Locusta migratoria

Genome ◽  
1993 ◽  
Vol 36 (5) ◽  
pp. 919-923 ◽  
Author(s):  
M. C. Pardo ◽  
E. Viseras ◽  
J. Cabrero ◽  
J. P. M. Camacho
Keyword(s):  
Dna Sequences ◽  
Locusta Migratoria ◽  
Supernumerary Chromosome ◽  
Rrna Genes ◽  
Single Female ◽  
Nucleolar Organizing Regions ◽  
Extra Segment ◽  
Accumulation Mechanism ◽  
Nucleolus Organiser ◽  
Nucleolus Organiser Region

A single female of Locusta migratoria was found to be heterozygous for a supernumerary heterochromatic segment distally located on the M6 autosome close to its nucleolus organiser region (NOR). Reactions to several chromosome banding techniques revealed its heterochromatic nature and its composition of GC-rich DNA sequences and likewise the NORs in this species. This suggests an origin for the extra segment by amplification of GC-rich DNA sequences contained in the distal NOR of the M6 chromosome, which is reinforced by the observation that the NOR of segmented M6 chromosomes produced the larger nucleolus in embryo prophase cells, such as would be expected from the presence of rRNA genes in the extra segment. No accumulation mechanism was detected in this female after analyzing the 213 embryo offspring produced, but an increase in the number of nucleoli per interphase nucleus was noted in heterozygous embryos in respect to standard homozygous ones.Key words: Locusta migratoria, supernumerary segments, nucleolar organizing regions, heterochromatin.

Karyotype of Araucaria angustifolia and the decondensation/activation mode of its nucleolus organiser region

2007 ◽  
Vol 55 (2) ◽  
pp. 165 ◽  
Author(s):  
Manoela Miranda ◽  
Cícero Carlos de Souza Almeida ◽  
Marcelo Guerra
Keyword(s):  
Transcriptional Activation ◽  
Chromosome Pair ◽  
Transcriptional Control ◽  
Rrna Genes ◽  
Araucaria Angustifolia ◽  
Organiser Region ◽  
C Banding ◽  
Diploid Complement ◽  
Nucleolus Organiser ◽  
Nucleolus Organiser Region

The chromosomes of the gymnosperm Araucaria angustifolia (Bertol.) Kuntze were analysed with the fluorochromes chromomycin A3 (CMA) and 4′,6-diamidino-2-phenylindole (DAPI) and with C-banding. This species contains a diploid complement made of 26 chromosomes, with 18 larger metacentric, four smaller metacentric and four submetacentric chromosomes. The only CMA+/DAPI– region observed corresponded to the nucleolus organiser region (NOR) localised at the proximal portion of a large metacentric chromosome pair. C-banding marked the NOR as well as a terminal region of another chromosome pair. In addition, small C-bands were occasionally seen interspersed in many chromosomes. The NOR appeared to condense at approximately the same rate as the rest of the chromosome from prophase throughout metaphase. In interphase nuclei, NOR decondensation and activation was characterised by the formation of CMA+ blocks that resembled a string of beads inside the nucleolus. The number and size of beads was inversely proportional to the size of the nucleolus, suggesting that transcriptional activation of the nucleolar cistrons starts simultaneously at several points of the NOR. The mode of NOR activation in A. angustifolia differs from that observed in most species, providing a unique opportunity to study activation and transcriptional control of rRNA genes.

Nucleotide polymorphisms in three genes support host and geographic speciation in tree pathogens belonging toGremmeniellaspp.

2002 ◽  
Vol 80 (11) ◽  
pp. 1151-1159 ◽  
Author(s):  
M Dusabenyagasani ◽  
G Laflamme ◽  
R C Hamelin
Keyword(s):  
North America ◽  
Dna Sequences ◽  
North American ◽  
Abies Balsamea ◽  
Host Specialization ◽  
Rrna Genes ◽  
Nucleotide Polymorphisms ◽  
Group I ◽  
Geographic Separation ◽  
Pinus Spp

We detected nucleotide polymorphisms within the genus Gremmeniella in DNA sequences of β-tubulin, glyceraldehyde phosphate dehydrogenase, and mitochondrial small subunit rRNA (mtSSU rRNA) genes. A group-I intron was present in strains originating from fir (Abies spp.) in the mtSSU rRNA locus. This intron in the mtSSU rRNA locus of strains isolated from Abies sachalinensis (Fridr. Schmidt) M.T. Mast in Asia was also found in strains isolated from Abies balsamea (L.) Mill. in North America. Phylogenetic analyses yielded trees that grouped strains by host of origin with strong branch support. Asian strains of Gremmeniella abietina (Lagerberg) Morelet var. abietina isolated from fir (A. sachalinensis) were more closely related to G. abietina var. balsamea from North America, which is found on spruce (Picea spp.) and balsam fir, and European and North American races of G. abietina var. abietina from pines (Pinus spp.) were distantly related. Likewise, North American isolates of Gremmeniella laricina (Ettinger) O. Petrini, L.E. Petrini, G. Laflamme, & G.B. Ouellette, a pathogen of larch, was more closely related to G. laricina from Europe than to G. abietina var. abietina from North America. These data suggest that host specialization might have been the leading evolutionary force shaping Gremmeniella spp., with geographic separation acting as a secondary factor.Key words: Gremmeniella, geographic separation, host specialization, mitochondrial rRNA, nuclear genes.

scholarly journals Variability of the Sheep Lung Microbiota

2016 ◽  
Vol 82 (11) ◽  
pp. 3225-3238 ◽  
Author(s):  
Laura Glendinning ◽  
Steven Wright ◽  
Jolinda Pollock ◽  
Peter Tennant ◽  
David Collie ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Dna Sequences ◽  
Bacterial Communities ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Large Animal ◽  
Local Factors ◽  
Adult Sheep ◽  
Sequencing Technologies ◽  
Host Influence

ABSTRACTSequencing technologies have recently facilitated the characterization of bacterial communities present in lungs during health and disease. However, there is currently a dearth of information concerning the variability of such data in health both between and within subjects. This study seeks to examine such variability using healthy adult sheep as our model system. Protected specimen brush samples were collected from three spatially disparate segmental bronchi of six adult sheep (age, 20 months) on three occasions (day 0, 1 month, and 3 months). To further explore the spatial variability of the microbiotas, more-extensive brushing samples (n= 16) and a throat swab were taken from a separate sheep. The V2 and V3 hypervariable regions of the bacterial 16S rRNA genes were amplified and sequenced via Illumina MiSeq. DNA sequences were analyzed using the mothur software package. Quantitative PCR was performed to quantify total bacterial DNA. Some sheep lungs contained dramatically different bacterial communities at different sampling sites, whereas in others, airway microbiotas appeared similar across the lung. In our spatial variability study, we observed clustering related to the depth within the lung from which samples were taken. Lung depth refers to increasing distance from the glottis, progressing in a caudal direction. We conclude that both host influence and local factors have impacts on the composition of the sheep lung microbiota.IMPORTANCEUntil recently, it was assumed that the lungs were a sterile environment which was colonized by microbes only during disease. However, recent studies using sequencing technologies have found that there is a small population of bacteria which exists in the lung during health, referred to as the “lung microbiota.” In this study, we characterize the variability of the lung microbiotas of healthy sheep. Sheep not only are economically important animals but also are often used as large animal models of human respiratory disease. We conclude that, while host influence does play a role in dictating the types of microbes which colonize the airways, it is clear that local factors also play an important role in this regard. Understanding the nature and influence of these factors will be key to understanding the variability in, and functional relevance of, the lung microbiota.

scholarly journals First Complete Genome Sequence of Brucella abortus 2308 isolated from an abortion storm in a dairy farm in India

2021 ◽  
Author(s):  
Amit Kumar ◽  
Malyaj R Prajapati ◽  
Surendra Upadhyay ◽  
Anamika Bhordia ◽  
Vinod Kumar Singh ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Dna Sequences ◽  
Brucella Abortus ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Messenger Rna ◽  
Gc Content ◽  
Dairy Farm ◽  
Rrna Genes ◽  
Sequence Length

Abstract The present report communicates the first complete genome sequence of Brucella abortus 2308 strain isolated from a an abortion storm in a dairy farm located at Kanpur, Uttar Pradesh in India. It caused the last trimester abortions of 32 animals out of 100 cows in a dairy over a period of 60 days. The bacteria were isolated in pure culture from the placenta of aborted cows. The genome sequence length of isolated bacteria is 3,285,606 bp with a 57.25 % GC content, an N50 value of 296,426, L50 value of 4 containing 3,119 coding DNA sequences (CDSs), 49 tRNAs, 1 transfer messenger RNA (mRNA), and 3 rRNA genes. It is the first report of Brucella abortus 2308 isolation and complete genome sequence from Indian subcontinent.

scholarly journals Upstream domains of the Xenopus laevis rDNA promoter are revealed in microinjected oocytes.

1986 ◽  
Vol 6 (4) ◽  
pp. 1228-1234 ◽  
Author(s):  
J Windle ◽  
B Sollner-Webb
Keyword(s):  
Xenopus Laevis ◽  
Dna Sequences ◽  
Promoter Region ◽  
Core Promoter ◽  
Rrna Genes ◽  
Deletion Mutants ◽  
Low Concentrations ◽  
Upstream Promoter ◽  
Polymerase I ◽  
Vector Dna

The DNA sequences involved in promoting transcription of the Xenopus laevis rRNA genes were determined by microinjecting a series of deletion mutants into oocyte nuclei. A very small promoter region is sufficient to direct efficient transcription when templates are microinjected at high rDNA concentration, since 5'delta- 9 and 3'delta +6 templates are fully active. However, as the concentration of injected template is decreased, an increasing requirement for upstream domains, extending to nucleotide approximately -170, is observed. The major downstream border of the required region does not change. This apparently expanding 5' promoter border results from the fact that, as the rDNA concentration is decreased, transcription from templates lacking the upstream promoter domain falls off much more sharply than does transcription from a complete promoter. In fact, the deleted promoters are virtually inactive below a threshold rDNA concentration. It is indeed the rDNA concentration that is important, for coinjected vector DNA does not increase the level of transcription obtained from low concentrations of the 5' deletions. From these data we conclude that polymerase I transcription factors can recognize and initiate transcription from a small core promoter domain, but that sequences extending upstream to nucleotide approximately -170 increase the efficiency of initiation. A model is presented that could account for these results.

scholarly journals Draft Genome Sequence of the Extremely Desiccation-Tolerant Cyanobacterium Gloeocapsopsis sp. Strain AAB1

2018 ◽  
Vol 6 (17) ◽  
Author(s):  
Fernando Puente-Sánchez ◽  
Carlos González-Silva ◽  
Victor Parro ◽  
Javier Tamames ◽  
Armando Azua-Bustos
Keyword(s):  
Genome Size ◽  
Genome Sequence ◽  
Dna Sequences ◽  
Draft Genome ◽  
Atacama Desert ◽  
Draft Genome Sequence ◽  
Rrna Genes ◽  
Trna Genes ◽  
Content Type

ABSTRACT Gloeocapsopsis sp. strain AAB1 is an extremely desiccation-tolerant cyanobacterium isolated from translucent quartz stones from the Atacama Desert (Chile). Here, we report its draft genome sequence, which consists of 137 contigs with an ∼5.4-Mb genome size. The annotation revealed 5,641 coding DNA sequences, 38 tRNA genes, and 5 rRNA genes.

scholarly journals Metagenomic Analysis of Kimchi, a Traditional Korean Fermented Food

2011 ◽  
Vol 77 (7) ◽  
pp. 2264-2274 ◽  
Author(s):  
Ji Young Jung ◽  
Se Hee Lee ◽  
Jeong Myeong Kim ◽  
Moon Su Park ◽  
Jin-Woo Bae ◽  
...  
Keyword(s):  
Microbial Community ◽  
Dna Sequences ◽  
Leuconostoc Mesenteroides ◽  
16S Rrna Genes ◽  
Read Length ◽  
Rrna Genes ◽  
Genetic Profile ◽  
Average Read Length ◽  
Metabolic Potential ◽  
Fermentation Products

ABSTRACTKimchi, a traditional food in the Korean culture, is made from vegetables by fermentation. In this study, metagenomic approaches were used to monitor changes in bacterial populations, metabolic potential, and overall genetic features of the microbial community during the 29-day fermentation process. Metagenomic DNA was extracted from kimchi samples obtained periodically and was sequenced using a 454 GS FLX Titanium system, which yielded a total of 701,556 reads, with an average read length of 438 bp. Phylogenetic analysis based on 16S rRNA genes from the metagenome indicated that the kimchi microbiome was dominated by members of three genera:Leuconostoc,Lactobacillus, andWeissella. Assignment of metagenomic sequences to SEED categories of the Metagenome Rapid Annotation using Subsystem Technology (MG-RAST) server revealed a genetic profile characteristic of heterotrophic lactic acid fermentation of carbohydrates, which was supported by the detection of mannitol, lactate, acetate, and ethanol as fermentation products. When the metagenomic reads were mapped onto the database of completed genomes, theLeuconostoc mesenteroidessubsp.mesenteroidesATCC 8293 andLactobacillus sakeisubsp.sakei23K genomes were highly represented. These same two genera were confirmed to be important in kimchi fermentation when the majority of kimchi metagenomic sequences showed very high identity toLeuconostoc mesenteroidesandLactobacillusgenes. Besides microbial genome sequences, a surprisingly large number of phage DNA sequences were identified from the cellular fractions, possibly indicating that a high proportion of cells were infected by bacteriophages during fermentation. Overall, these results provide insights into the kimchi microbial community and also shed light on fermentation processes carried out broadly by complex microbial communities.

Copro-PCR based detection of bovine schistosome infection in India

2015 ◽  
Vol 90 (1) ◽  
pp. 102-107 ◽  
Author(s):  
B. Lakshmanan ◽  
K. Devada ◽  
S. Joseph ◽  
T.V. Aravindakshan ◽  
L. Sabu
Keyword(s):  
Mitochondrial Dna ◽  
Ribosomal Rna ◽  
Dna Sequences ◽  
Rrna Genes ◽  
12S Rrna ◽  
Gene Sequences ◽  
Schistosome Infection ◽  
Faecal Samples ◽  
Polymerase Chain ◽  
Trematode Infections

AbstractSchistosomosis and amphistomosis are the two economically important and widely prevalent snail-borne trematode infections in grazing cattle of southern India. Acute infections are symptomatically similar and difficult to detect by routine microscopy for eggs. The present study was directed towards the development of a copro-polymerase chain reaction (copro-PCR) for detection of bovine schistosome species, using custom-designed primers targeting 18S and 28S ribosomal RNA as well as mitochondrial DNA. The study demonstrated the enhanced diagnostic specificity of mitochondrial DNA markers over ribosomal RNA genes as genus-specific probes to detect schistosomes. We developed a sensitive PCR assay using primers designed from mitochondrial DNA sequences targeting the partialrrnl(16S rRNA), tCys (transfer RNA for cysteine) and partialrrnS(12S rRNA) genes ofSchistosoma spindaleto specifically detect schistosome infection from faecal samples of naturally infected bovines. The salient findings of the work also throw light on to the high similarity of the ribosomal RNA gene sequences of schistosomes with those ofGastrothylax crumeniferandFischoederius elongatus,the most prevalent pouched amphistomes of the region. Further investigation has to be directed towards unravelling the complete gene sequences of 18S and 28S ribosomal RNA as well as mitochondrial DNA sequences of amphistome isolates from India.

scholarly journals Chiasma redistribution in presence of supernumerary chromosome segments in grasshoppers: dependence on the size of the extra segment

Heredity ◽  
1987 ◽  
Vol 58 (3) ◽  
pp. 409-412 ◽  
Author(s):  
Jesús Navas-Castillo ◽  
Josefa Cabrero ◽  
Juan Pedro M Camacho
Keyword(s):  
Supernumerary Chromosome ◽  
Extra Segment ◽  
Chromosome Segments

scholarly journals Direct and Rapid Detection by PCR ofErysipelothrix sp. DNAs Prepared from Bacterial Strains and Animal Tissues

1999 ◽  
Vol 37 (12) ◽  
pp. 4093-4098 ◽  
Author(s):  
Kouichi Takeshi ◽  
Souichi Makino ◽  
Tetsuya Ikeda ◽  
Noriko Takada ◽  
Atsushi Nakashiro ◽  
...  
Keyword(s):  
16S Rrna ◽  
Gene Cluster ◽  
Dna Sequences ◽  
Screening Method ◽  
Rapid Screening ◽  
Rrna Genes ◽  
23S Rrna ◽  
Rrna Gene ◽  
Link Type ◽  
Species Specific

A PCR method for rapid screening of Erysipelothrix spp. in the slaughterhouse was carried out by using four species-specific sets of oligonucleotide primers after initial amplification with the primer set MO101-MO102, which amplifies the 16S rRNA sequences of all four Erysipelothrix species. The DNA sequences coding for the rRNA gene cluster, including 16S rRNA, 23S rRNA, and the noncoding region downstream of 5S rRNA, were determined in order to design primers for the species-specific PCR detection system. The homology among the 4.5-kb DNA sequences of the rRNA genes ofErysipelothrix rhusiopathiae serovar 2 (DNA Data Bank of Japan accession no. AB019247), E. tonsillarum serovar 7 (accession no. AB019248), E. rhusiopathiae serovar 13 (accession no. AB019249), and E. rhusiopathiae serovar 18 (accession no. AB019250) ranged from 96.0 to 98.4%. The PCR amplifications were specific and were able to distinguish the DNAs from each of the four Erysipelothrix species. The results of PCR tests performed directly with tissue specimens from diseased animals were compared with the results of cultivation tests, and the PCR tests were completed within 5 h. The test with this species-specific system based on PCR amplification with the DNA sequences coding for the rRNA gene cluster was an accurate, easy-to-read screening method for rapid diagnosis of Erysipelothrix sp. infection in the slaughterhouse.

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