A repeated sequence probe for the C genome in Avena (Oats)

1990 ◽  
Vol 79 (1) ◽  
pp. 1-7 ◽  
Author(s):  
S. Fabijanski ◽  
G. Fedak ◽  
K. Armstrong ◽  
I. Altosaar
Keyword(s):  
Repeated Sequence ◽  
Sequence Probe ◽  
C Genome

Potential of the C Genome of Different Variants of Brassica oleracea for the Improvement of Agronomic and Seed Quality Traits of B. napus Canola

Crop Science ◽  
2019 ◽  
Vol 59 (6) ◽  
pp. 2608-2620 ◽  
Author(s):  
Azam Nikzad ◽  
Berisso Kebede ◽  
Jaime Pinzon ◽  
Jani Bhavikkumar ◽  
Rong-Cai Yang ◽  
...  
Keyword(s):  
Brassica Oleracea ◽  
Seed Quality ◽  
Quality Traits ◽  
C Genome ◽  
Seed Quality Traits

Male Sterility and Meiotic Drive Associated With Sex Chromosome Rearrangements in Drosophila: Role of X-Y Pairing

Genetics ◽  
1998 ◽  
Vol 149 (1) ◽  
pp. 143-155 ◽  
Author(s):  
Bruce D McKee ◽  
Kathy Wilhelm ◽  
Cynthia Merrill ◽  
Xiao-jia Ren
Keyword(s):  
Male Sterility ◽  
Sex Chromosome ◽  
Meiotic Drive ◽  
Repeated Sequence ◽  
Meiotic Pairing ◽  
Intergenic Spacers ◽  
Male Specific ◽  
The Relationship ◽  
Novel Model

Abstract In Drosophila melanogaster, deletions of the pericentromeric X heterochromatin cause X-Y nondisjunction, reduced male fertility and distorted sperm recovery ratios (meiotic drive) in combination with a normal Y chromosome and interact with Y-autosome translocations (T(Y;A)) to cause complete male sterility. The pericentromeric heterochromatin has been shown to contain the male-specific X-Y meiotic pairing sites, which consist mostly of a 240-bp repeated sequence in the intergenic spacers (IGS) of the rDNA repeats. The experiments in this paper address the relationship between X-Y pairing failure and the meiotic drive and sterility effects of Xh deletions. X-linked insertions either of complete rDNA repeats or of rDNA fragments that contain the IGS were found to suppress X-Y nondisjunction and meiotic drive in Xh−/Y males, and to restore fertility to Xh−/T(Y;A) males for eight of nine tested Y-autosome translocations. rDNA fragments devoid of IGS repeats proved incapable of suppressing either meiotic drive or chromosomal sterility. These results indicate that the various spermatogenic disruptions associated with X heterochromatic deletions are all consequences of X-Y pairing failure. We interpret these findings in terms of a novel model in which misalignment of chromosomes triggers a checkpoint that acts by disabling the spermatids that derive from affected spermatocytes.

scholarly journals Repeated sequence organization and RNA transcription map of the chicken adult beta-globin gene region.

1981 ◽  
Vol 256 (4) ◽  
pp. 1502-1505
Author(s):  
W.I. Wood ◽  
J. Nickol ◽  
G. Felsenfeld
Keyword(s):  
Globin Gene ◽  
Repeated Sequence ◽  
Gene Region ◽  
Beta Globin ◽  
Rna Transcription ◽  
Sequence Organization ◽  
Beta Globin Gene ◽  
Transcription Map

scholarly journals Streptococcal Adhesion and Colonization

1997 ◽  
Vol 8 (2) ◽  
pp. 175-200 ◽  
Author(s):  
H.F. Jenkinson ◽  
RJ Lamont
Keyword(s):  
Immune Modulation ◽  
Rational Design ◽  
Repeated Sequence ◽  
Host Cells ◽  
Mammalian Host ◽  
Related Factors ◽  
Bacterial Populations ◽  
Acellular Vaccines

Streptococci express arrays of adhesins on their cell surfaces that facilitate adherence to substrates present in their natural environment within the mammalian host. A consequence of such promiscuous binding ability is that streptococcal cells may adhere simultaneously to a spectrum of substrates, including salivary glycoproteins, extracellular matrix and serum components, host cells, and other microbial cells. The multiplicity of streptococcal adherence interactions accounts, at least in part, for their success in colonizing the oral and epithelial surfaces of humans. Adhesion facilitates colonization and may be a precursor to tissue invasion and immune modulation, events that presage the development of disease. Many of the streptococcal adhesins and virulence-related factors are cell-wall-associated proteins containing repeated sequence blocks of amino acids. Linear sequences, both within the blocks and within non-repetitive regions of the proteins, have been implicated in substrate binding. Sequences and functions of these proteins among the streptococci have become assorted through gene duplication and horizontal transfer between bacterial populations. Several adhesins identified and characterized through in vitro binding assays have been analyzed for in vivo expression and function by means of animal models used for colonization and virulence. Information on the molecular structure of adhesins as related to their in vivo function will allow for the rational design of novel acellular vaccines, recombinant antibodies, and adhesion agonists for the future control or prevention of streptococcal colonization and streptococcal diseases.

Homeology Between the Chromosomes of Avena macrostachya and the Avena C Genome

1991 ◽  
Vol 106 (3) ◽  
pp. 250-253 ◽  
Author(s):  
W. Pohler ◽  
H.-D. Hoppe
Keyword(s):  
C Genome

Clusters of interspersed repeated DNA sequences in the rice genome (Oryza)

Genome ◽  
1993 ◽  
Vol 36 (5) ◽  
pp. 944-953 ◽  
Author(s):  
Xinping Zhao ◽  
Gary Kochert
Keyword(s):  
Dna Sequences ◽  
Blot Hybridization ◽  
Rice Genome ◽  
Repeated Sequence ◽  
Repeated Sequences ◽  
Repeated Dna ◽  
Rice Varieties ◽  
Slot Blot Hybridization ◽  
Repeated Dna Sequence ◽  
Genus Oryza

We have characterized a repeated DNA sequence (RTL 122) from rice (Oryza sauva L.) with respect to its organization in the rice genome and its distribution among rice and other plants. The results indicate that the RTL 122 sequence is interspersed in the rice genome and limited to the genus Oryza. It is highly polymorphic and can be used to fingerprint rice varieties. A structure was observed in which several repeated sequences were clustered in DNA regions of 15–20 kb. We characterized three bacteriophage lambda clones that contained the RTL 122 sequence. Southern analysis using probes derived from restriction fragments of the three lambda clones indicated that all fragments except one are interspersed repeated sequences and belong to different repeated sequence families. Subsequent slot blot hybridization showed that most of them are only present within the genus Oryza. Some of the Oryza-specific, physically linked sequences show the same phylogenetic distribution, which suggests that these sequences might have evolved in a coordinate fashion. On the other hand, some of the repeated sequences have a different distribution even though they are physically adjacent in the genome. We speculate that such blocks of interspersed repeated sequences may serve as hotspots for rapid changes in the rice genome.Key words: rice, Oryza, repeated sequences, DNA fingerprinting, coordinated evolution.

CHROMOSOME RELATIONSHIPS BETWEEN THE CULTIVATED OAT AVENA SATIVA (6x) AND A. VENTRICOSA (2x)

1970 ◽  
Vol 12 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Hugh Thomas
Keyword(s):  
Chromosome Pairing ◽  
Avena Sativa ◽  
Diploid Species ◽  
Meiotic Behaviour ◽  
Hexaploid Species ◽  
C Genome

Chromosome pairing in the F1 hybrid between the cultivated oat Avena sativa and a diploid species A. ventricosa, and in the derived amphiploid, shows that the diploid species is related to one of the genomes of the hexaploid species. The amount of chromosome pairing observed in complex interamphiploid hybrids demonstrates further that A. ventricosa is related to the C. genome of A. sativa. However, the chromosomes of the diploid species have become differentiated from that of the C genome of A. sativa and this is readily apparent in the meiotic behaviour of both the F1 hybrid and the amphiploid.

A species-specific satellite DNA from the entomopathogenic nematode Heterorhabditis indicus

Genome ◽  
1998 ◽  
Vol 41 (2) ◽  
pp. 148-153 ◽  
Author(s):  
Monique Abadon ◽  
Eric Grenier ◽  
Christian Laumond ◽  
Pierre Abad
Keyword(s):  
Dna Sequence ◽  
Satellite Dna ◽  
Tandem Repeats ◽  
Sequence Data ◽  
Entomopathogenic Nematode ◽  
Consensus Sequence ◽  
Repeated Sequence ◽  
Nucleotide Sequence Analysis ◽  
Specific Sequence ◽  
Species Specific

An AluI satellite DNA family has been cloned from the entomopathogenic nematode Heterorhabditis indicus. This repeated sequence appears to be an unusually abundant satellite DNA, since it constitutes about 45% of the H. indicus genome. The consensus sequence is 174 nucleotides long and has an A + T content of 56%, with the presence of direct and inverted repeat clusters. DNA sequence data reveal that monomers are quite homogeneous. Such homogeneity suggests that some mechanism is acting to maintain the homogeneity of this satellite DNA, despite its abundance, or that this repeated sequence could have appeared recently in the genome of H. indicus. Hybridization analysis of genomic DNAs from different Heterorhabditis species shows that this satellite DNA sequence is specific to the H. indicus genome. Considering the species specificity and the high copy number of this AluI satellite DNA sequence, it could provide a rapid and powerful tool for identifying H. indicus strains.Key words: AluI repeated DNA, tandem repeats, species-specific sequence, nucleotide sequence analysis.

scholarly journals Positive Regulation of fur Gene Expression via Direct Interaction of Fur in a Pathogenic Bacterium, Vibrio vulnificus

2007 ◽  
Vol 189 (7) ◽  
pp. 2629-2636 ◽  
Author(s):  
Hyun-Jung Lee ◽  
So Hyun Bang ◽  
Kyu-Ho Lee ◽  
Soon-Jung Park
Keyword(s):  
Gene Expression ◽  
Pathogenic Bacteria ◽  
Vibrio Vulnificus ◽  
Iron Concentration ◽  
Direct Interaction ◽  
Repeated Sequence ◽  
Upstream Region ◽  
Fur Protein

ABSTRACT In pathogenic bacteria, the ability to acquire iron, which is mainly regulated by the ferric uptake regulator (Fur), is essential to maintain growth as well as its virulence. In Vibrio vulnificus, a human pathogen causing gastroenteritis and septicemia, fur gene expression is positively regulated by Fur when the iron concentration is limited (H.-J. Lee et al., J. Bacteriol. 185:5891-5896, 2003). Footprinting analysis revealed that an upstream region of the fur gene was protected by the Fur protein from DNase I under iron-depleted conditions. The protected region, from −142 to −106 relative to the transcription start site of the fur gene, contains distinct AT-rich repeats. Mutagenesis of this repeated sequence resulted in abolishment of binding by Fur. To confirm the role of this cis-acting element in Fur-mediated control of its own gene in vivo, fur expression was monitored in V. vulnificus strains using a transcriptional fusion containing the mutagenized Fur-binding site (fur mt::luxAB). Expression of fur mt::luxAB showed that it was not regulated by Fur and was not influenced by iron concentration. Therefore, this study demonstrates that V. vulnificus Fur acts as a positive regulator under iron-limited conditions by direct interaction with the fur upstream region.

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