Reorganization of unique and repetitive sequences during nuclear development in Tetrahymena thermophila

1982 ◽  
Vol 60 (9) ◽  
pp. 847-853 ◽  
Author(s):  
Clifford F. Brunk ◽  
Smiley G. S. Tsao ◽  
Catherine H. Diamond ◽  
Pamela S. Ohashi ◽  
Nora N. G. Tsao ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Nuclear Dna ◽  
Tetrahymena Thermophila ◽  
Repetitive Sequences ◽  
Repeated Sequence ◽  
Sequence Family ◽  
Sequence Element ◽  
Genomic Libraries ◽  
Hybridization Probes ◽  
Nuclear Development

Genomic libraries of macro- and micro-nuclear DNA of the ciliate protozoan Tetrahymena thermophila were constructed in the bacteriophage vector λgtWESλB. Screening of these libraries with a probe for the repeated hexanucleotide sequence C4A2 showed many phage from the micronuclear library but few if any macronuclear sequences having homology to this probe. This is consistent with C4A2-repeating elements being present predominantly if not exclusively at or near the termini of macronuclear DNA. Sequences flanking C4A2-repeating elements were isolated from a number of purified phage and were used as hybridization probes to restriction endonuclease digested macro- and micro-nuclear DNA. These experiments revealed a repeated sequence family as well as unique sequences present only in micronuclear DNA. The repeated sequence element appears to be dispersed throughout the genome. Phage-containing individual members of this micronucleus limited sequence family were purified from the micronuclear library. Some of these phage contained sequences which hybridized to macronuclear DNA. These fragments therefore contain a "transition" region between micronucleus-limited sequences and sequences present in both nuclei.

Micronuclear DNA sequences from Tetrahymena do not confer mitotic stability on ARS plasmids in Saccharomyces

Genome ◽  
1988 ◽  
Vol 30 (5) ◽  
pp. 690-696 ◽  
Author(s):  
Wendy H. Horsfall ◽  
Ronald E. Pearlman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Sequences ◽  
Copy Number ◽  
Tetrahymena Thermophila ◽  
Assay System ◽  
Mitotic Stability ◽  
Yeast Saccharomyces Cerevisiae ◽  
Genomic Libraries ◽  
Ade2 Gene

Genomic libraries containing micronuclear DNA sequences from Tetrahymena thermophila have been constructed in a vector containing ARS1, SUP11, and ura3 sequences from the yeast Saccharomyces cerevisiae. When transformed into a strain of S. cerevisiae carrying a suppressible ochre mutation in the ade2 gene, viable transformants are obtained only if the transforming plasmid is maintained at a copy number of one or two per cell. Mitotic segregation of the plasmid is easily assessed in a colour assay of transformants. Using this assay system, we showed that micronuclear DNA from Tetrahymena does not contain sequences that confer mitotic stability on yeast ARS-containing plasmids; i.e., sequences that function analogously to yeast centromere sequences. One transformant was analyzed that carries Tetrahymena sequences that maintain the copy number of the ARS plasmid at one or two per cell. However, these sequences do not confer mitotic stability on the transformants and they confer a phenotype in this assay similar to that of the REP3 gene of the yeast 2 μm plasmid.Key words: mitotic stability, centromere, Tetrahymena, Saccharomyces.

scholarly journals A method for mapping germ line sequences in Tetrahymena thermophila using the polymerase chain reaction.

Genetics ◽  
1994 ◽  
Vol 137 (1) ◽  
pp. 95-106 ◽  
Author(s):  
D Cassidy-Hanley ◽  
M C Yao ◽  
P J Bruns
Keyword(s):  
Polymerase Chain Reaction ◽  
Dna Sequences ◽  
Tetrahymena Thermophila ◽  
Germ Line ◽  
Repetitive Sequences ◽  
Mapping Technique ◽  
Ciliated Protozoan ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Template Dna

Abstract A method for mapping DNA sequences to specific germinal chromosomes in the ciliated protozoan Tetrahymena thermophila has been developed. This mapping technique (PCR mapping) utilizes the polymerase chain reaction and template DNA derived from nullisomic strains to directly assign micronuclear DNA sequences to specific micronuclear chromosomes. Using this technique, a number of unique sequences and short repetitive sequences flanked by unique sequences have been mapped to four of the five germinal chromosomes.

Amplification of DNA sequences in wheat and its relatives: the Dgas44 and R350 families of repetitive sequences

Genome ◽  
1994 ◽  
Vol 37 (2) ◽  
pp. 320-327 ◽  
Author(s):  
D. McNeil ◽  
E. S. Lagudah ◽  
U. Hohmann ◽  
R. Appels
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequences ◽  
Repetitive Sequences ◽  
Tetraploid Wheat ◽  
Genomic Clone ◽  
Sequence Family ◽  
Chain Reaction ◽  
D Genome ◽  
Polymerase Chain

The sequence of a Triticum tauschii genomic clone representing a family of D-genome amplified DNA sequences, designated Dgas44, is reported. The Dgas44 sequence occurs on all chromosomes of the D genome of wheat, Triticum aestivum, and in situ hybridization revealed it to be evenly dispersed on all seven chromosome pairs. An internal HindIII fragment of Dgas44, designated Dgas44-3, defines the highly amplified region that is specific to the D genome. The polymerase chain reaction was used to amplify a 236-bp fragment within Dgas44-3 from chromosomes 1D, 2D, 3D, 4D, 5D, and 7D, and identical copies of this region of the Dgas44-3 sequence were found among the isolates from each of the chromosomes. The Dgas44-3 sequence population from specific chromosomes differed on average by 0.22% from the original Dgas44 sequence. The Dgas44 sequence was found to differentiate between the D genome present in T. aestivum, T. tauschii, hexaploid T. crassum, T. cylindricum, T. ventricosum, in which the sequence was present in a highly amplified form and T. juvenale, T. syriacum, and tetraploid T. crassum where the sequence family was difficult to detect. Another class of amplified sequences previously considered to be rye "specific." R350, was isolated from tetraploid wheat and its dispersed distribution on chromosomes was similar to the Dgas44 family in T. tauschii. In contrast with the Dgas44 sequence family, genome specificity for the remnant R350 sequence family was not evident since it was present on all wheat chromosomes.Key words: D genome, sequence amplification, in situ hybridization.

Verteilung und enzymatische Hypermethylierung invers repetitiver DNA-Sequenzen in verschiedenen Mäuse-und menschlichen Zellen / Distribution and Enzymic Hypermethylation of Inverted DNA Repeats in Different Murine and Human Cells

1979 ◽  
Vol 34 (7-8) ◽  
pp. 558-564 ◽  
Author(s):  
Thomas L. J. Boehm ◽  
Dusan Drahovsky
Keyword(s):  
Dna Sequences ◽  
Mammalian Cells ◽  
Nuclear Dna ◽  
Repetitive Sequences ◽  
Specific Class ◽  
Dna Repeats ◽  
Quantitative Analyses ◽  
Chang Cells ◽  
P815 Mouse

Abstract A specific class of DNA sequences, the inverted repetitive sequences, forms a double-stranded structure within a single linear polynucleotide chain in denatured DNA. The reassociation process is unimolecular and occurs very fast. Quantitative analyses have shown that these sequences com-E rise about 4-5% of the nuclear DNA of various mammalian cells (P815 mouse mastocytoma, Hela, L cells, Raji and Chang cells, and human embryonic hepatocytes) and are interspersed within sequences of other degrees of repetitiveness.After labeling the cells with L-[Metnyl-3H]methionine and [14C]deoxycytidine, relative rates of enzymic DNA methylation were computed on the basis of 3H and 14C radioactivities found in py­ rimidine residues of the nuclear DNA. The results indicate that DNA of inverted repetitive sequences is methylated to a level about 50% higher than the ordinary repetitive sequences and to about 300% higher than the unique and intermediary sequences.The biological function of the inverted repeats as well as the role of their enzymic hypermethyl­ ation is unknown.

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.

scholarly journals Phylogenetic relationships of Cranichidinae and Prescottiinae (Orchidaceae, Cranichideae) inferred from plastid and nuclear DNA sequences

2009 ◽  
Vol 104 (3) ◽  
pp. 403-416 ◽  
Author(s):  
Gerardo A. Salazar ◽  
Lidia I. Cabrera ◽  
Santiago Madriñán ◽  
Mark W. Chase
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Relationships ◽  
Nuclear Dna

Multiple calmodulin mRNA species are derived from two distinct genes

1987 ◽  
Vol 7 (5) ◽  
pp. 1873-1880
Author(s):  
H Nojima ◽  
K Kishi ◽  
H Sokabe
Keyword(s):  
Dna Sequences ◽  
Northern Blotting ◽  
Amino Acid Sequences ◽  
Cdna Clones ◽  
Rat Tissues ◽  
Coding Region ◽  
Genomic Libraries ◽  
Mrna Species ◽  
Nuclease Mapping ◽  
Rat Genome

We have observed three calmodulin mRNA species in rat tissues. In order to know from how many expressed genes they are derived, we have investigated the genomic organization of calmodulin genes in the rat genome. From a rat brain cDNA library, we obtained two kinds of cDNAs (pRCM1 and pRCM3) encoding authentic calmodulin. DNA sequence analysis of these cDNA clones revealed substitutions of nucleotides at 73 positions of 450 nucleotides in the coding region, although the amino acid sequences of these calmodulins are exactly the same. DNA sequences in the 5' and 3' noncoding regions are quite different between these two cDNAs. From these results, we conclude that they are derived from two distinct bona fide calmodulin genes, CaMI (pRCM1) and CaMII (pRCM3). Total genomic Southern hybridization suggested four distinct calmodulin-related genes in the rat genome. By cloning and sequencing the calmodulin-related genes from rat genomic libraries, we demonstrated that the other two genes are processed pseudogenes generated from the CaMI (lambda SC9) and CaMII (lambda SC8) genes, respectively, through an mRNA-mediated process of insertions. Northern blotting showed that the CaMI gene is transcribed in liver, muscle, and brain in similar amounts, whereas the CaMII gene is transcribed mainly in brain. S1 nuclease mapping indicated that the CaMI gene produced two mRNA species (1.7 and 4 kilobases), whereas the CaMII gene expressed a single mRNA species (1.4 kilobases).

Elimination of micronuclear specific DNA sequences early in anlagen development

1985 ◽  
Vol 5 (1) ◽  
pp. 93-98
Author(s):  
C F Brunk ◽  
R K Conover
Keyword(s):  
Developmental Stage ◽  
Dna Sequences ◽  
Developmental Stages ◽  
Tetrahymena Thermophila ◽  
Southern Analysis ◽  
Limited Sequence

After conjugation in Tetrahymena thermophila, the old macronuclei degenerate, and new macronuclei (anlagen) develop. During anlagen development a number of DNA sequences found in the micronuclear genome (micronuclear limited sequences) are eliminated from the anlagen. A cloned copy of a repetitive micronuclear limited sequence has been used to determine the developmental stage at which micronuclear limited sequences are eliminated. DNAs from anlagen of various developmental stages were examined by Southern analysis. It was found that micronuclear limited sequences are present in 4C anlagen and essentially absent in 8C and 16C anlagen. The precipitous loss of these sequences in the 8C anlagen rules out under-replication as the mechanism for the loss and suggests that these sequences are specifically degraded early during anlagen development.

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