Molecular characterization and chromosomal mapping of the 5S rRNA gene in Solea senegalensis: a new linkage to the U1, U2, and U5 small nuclear RNA genes

Genome ◽  
2006 ◽  
Vol 49 (1) ◽  
pp. 79-86 ◽  
Author(s):  
Manuel Manchado ◽  
Eugenia Zuasti ◽  
Ismael Cross ◽  
Alejandro Merlo ◽  
Carlos Infante ◽  
...  

Some units of the 5S rDNA of Solea senegalensis were amplified by PCR and sequenced. Three main PCR products (227, 441, and 2166 bp) were identified. The 227- and 441-bp fragments were characterized by highly divergent nontranscribed spacer sequences (referred to as NTS-I and NTS-II) that were 109 and 324 bp long, respectively, yet their coding sequences were nearly identical. The 2166-bp 5S rDNA unit was composed of two 5S rRNA genes separated by NTS-I and followed by a 1721-bp spacer containing the U2, U5, and U1 small nuclear RNA genes (snRNAs). They were inverted and arranged in the transcriptional direction opposite that of the 5S rRNA gene. This simultaneous linkage of 3 different snRNAs had never been observed before. The PCR products were used as probes in fluorescence in situ hybridization experiments to locate the corresponding loci on the chromosomes of S. senegalensis. A major 5S rDNA chromosomal site was located along most of the short arm of a submetacentric pair, while a minor site was detected near the centromeric region of an acrocentric pair.Key words: soleidae, pleuronectiformes, 5S rDNA, Solea, snRNAs linkage.

Genome ◽  
2001 ◽  
Vol 44 (3) ◽  
pp. 331-335 ◽  
Author(s):  
Franca Pelliccia ◽  
Rita Barzotti ◽  
Elisabetta Bucciarelli ◽  
Angela Rocchi

We investigated the 5S ribosomal RNA (rRNA) genes of the isopod crustacean Asellus aquaticus. Using PCR amplification, three different tandemly repeated units containing 5S rDNA were identified. Two of the three sequences were cloned and sequenced. One of them was 1842 bp and presented a 5S rRNA gene and a U1 small nuclear RNA (snRNA) gene. This type of linkage had never been observed before. The other repeat consisted of 477 bp and contained only an incomplete 5S rRNA gene lacking the first eight nucleotides and a spacer sequence. The third sequence was 6553 bp long and contained a 5S rRNA gene and the four core histone genes. The PCR products were used as probes in fluorescent in situ hybridization (FISH) experiments to locate them on chromosomes of A. aquaticus. The possible evolutionary origin of the three repeated units is discussed.Key words: Asellus, isopoda, crustacea, 5S rDNA, U1 snDNA.


Genome ◽  
2000 ◽  
Vol 43 (1) ◽  
pp. 213-215 ◽  
Author(s):  
Guy Drouin

The analyses of previously described 5S rRNA gene sequences show that some of the expressed 5S rRNA genes present in the mouse and rat genomes were derived from the retrotransposition of 5S rRNA transcripts. These analyses demonstrate that new 5S rRNA gene copies can originate by retrotransposition and that some of these retrotranscribed genes are expressed. Key words: 5S ribosomal RNA genes, retrotransposition, retroposons.


Genome ◽  
2001 ◽  
Vol 44 (5) ◽  
pp. 903-910 ◽  
Author(s):  
Cesar Martins ◽  
Pedro Manoel Galetti Jr.

To address understanding the organization of the 5S rRNA multigene family in the fish genome, the nucleotide sequence and organization array of 5S rDNA were investigated in the genus Leporinus, a representative freshwater fish group of South American fauna. PCR, subgenomic library screening, genomic blotting, fluorescence in situ hybridization, and DNA sequencing were employed in this study. Two arrays of 5S rDNA were identified for all species investigated, one consisting of monomeric repeat units of around 200 bp and another one with monomers of 900 bp. These 5S rDNA arrays were characterized by distinct NTS sequences (designated NTS-I and NTS-II for the 200- and 900-bp monomers, respectively); however, their coding sequences were nearly identical. The 5S rRNA genes were clustered in two chromosome loci, a major one corresponding to the NTS-I sites and a minor one corresponding to the NTS-II sites. The NTS-I sequence was variable among Leporinus spp., whereas the NTS-II was conserved among them and even in the related genus Schizodon. The distinct 5S rDNA arrays might characterize two 5S rRNA gene subfamilies that have been evolving independently in the genome.Key words: 5S rDNA, 5S rRNA gene, nontranscribed spacer, Leporinus, fish.


Genome ◽  
2001 ◽  
Vol 44 (1) ◽  
pp. 143-146 ◽  
Author(s):  
Dharam Singh ◽  
Mahipal Singh

The 5S rRNA genes in the Camellia sinensis (L.) O. Kuntze (tea) genome are arranged as tandem repeat units of 300 and 325 bps. The 2 classes of tandem repeats were discovered by Southern hybridisation of tea genomic DNA with a 5S rRNA gene PCR product.Key words: Camellia species, 5S rDNA, multigene family, tandem repeats, spacers.


1986 ◽  
Vol 205 (3) ◽  
pp. 428-433 ◽  
Author(s):  
Christoph Taschke ◽  
Mo-Quen Klinkert ◽  
Jörn Wolters ◽  
Richard Herrmann

2021 ◽  
Author(s):  
Joshua Vacarizas ◽  
Takahiro Taguchi ◽  
Takuma Mezaki ◽  
Masatoshi Okumura ◽  
Rei Kawakami ◽  
...  

Abstract The short and similar sized chromosomes of Acropora pose a challenge for karyotyping. Conventional methods, such as staining of heterochromatic regions, provide unclear banding patterns that hamper identification of such chromosomes. In this study, we used short single-sequence probes for tandemly repetitive 5S ribosomal RNA (rRNA) and core histone genes to identify specific chromosomes of Acropora pruinosa. Both the probes produced intense signals in fluorescence in situ hybridization, which distinguished chromosome pairs. The locus of the core histone gene was on chromosome 8, whereas that of 5S rRNA gene was on chromosome 5. The sequence of the 5S rRNA probe was composed largely of U1 and U2 spliceosomal small nuclear RNA (snRNA) genes and their interspacers, flanked by short sequences of the 5S rRNA gene. This is the first report of a tandemly repetitive linkage of snRNA and 5S rRNA genes in Cnidaria. Based on the constructed tentative karyogram and whole genome hybridization, the longest chromosome pair (chromosome 1) was heteromorphic. The probes also hybridized effectively with chromosomes of other Acropora species and population, revealing an additional core histone gene locus. We demonstrated the applicability of short-sequence probes as chromosomal markers with potential for use across populations and species of Acropora.


1989 ◽  
Vol 9 (10) ◽  
pp. 4416-4421
Author(s):  
W S Grayburn ◽  
E U Selker

5S rRNA genes of Neurospora crassa are generally dispersed in the genome and are unmethylated. The xi-eta region of Oak Ridge strains represents an informative exception. Most of the cytosines in this region, which consists of a diverged tandem duplication of a 0.8-kilobase-pair segment including a 5S rRNA gene, appear to be methylated (E. U. Selker and J. N. Stevens, Proc. Natl. Acad. Sci. USA 82:8114-8118, 1985). Previous work demonstrated that the xi-eta region functions as a portable signal for de novo DNA methylation (E. U. Selker and J. N. Stevens, Mol. Cell. Biol. 7:1032-1038, 1987; E. U. Selker, B. C. Jensen, and G. A. Richardson, Science 238:48-53, 1987). To identify the structural basis of this property, we have isolated and characterized an unmethylated allele of the xi-eta region from N. crassa Abbott 4. The Abbott 4 allele includes a single 5S rRNA gene, theta, which is different from all previously identified Neurospora 5S rRNA genes. Sequence analysis suggests that the xi-eta region arose from the theta region by duplication of a 794-base-pair segment followed by 267 G.C to A.T mutations in the duplicated DNA. The distribution of these mutations is not random. We propose that the RIP process of N. crassa (E. U. Selker, E. B. Cambareri, B. C. Jensen, and K. R. Haack, Cell 51:741-752, 1987; E. U. Selker, and P. W. Garrett, Proc. Natl. Acad. Sci. USA 85:6870-6874, 1988; E. B. Cambareri, B. C. Jensen, E. Schabtach, and E. U. Selker, Science 244:1571-1575, 1989) is responsible for the numerous transition mutations and DNA methylation in the xi-eta region. A long homopurine-homopyrimidine stretch immediately following the duplicated segment is 9 base pairs longer in the Oak Ridge allele than in the Abbott 4 allele. Triplex DNA, known to occur in homopurine-homopyrimidine sequences, may have mediated the tandem duplication.


2020 ◽  
Vol 21 (8) ◽  
pp. 2931 ◽  
Author(s):  
Ruslan Kalendar ◽  
Olga Raskina ◽  
Alexander Belyayev ◽  
Alan H. Schulman

Retrotransposable elements are widely distributed and diverse in eukaryotes. Their copy number increases through reverse-transcription-mediated propagation, while they can be lost through recombinational processes, generating genomic rearrangements. We previously identified extensive structurally uniform retrotransposon groups in which no member contains the gag, pol, or env internal domains. Because of the lack of protein-coding capacity, these groups are non-autonomous in replication, even if transcriptionally active. The Cassandra element belongs to the non-autonomous group called terminal-repeat retrotransposons in miniature (TRIM). It carries 5S RNA sequences with conserved RNA polymerase (pol) III promoters and terminators in its long terminal repeats (LTRs). Here, we identified multiple extended tandem arrays of Cassandra retrotransposons within different plant species, including ferns. At least 12 copies of repeated LTRs (as the tandem unit) and internal domain (as a spacer), giving a pattern that resembles the cellular 5S rRNA genes, were identified. A cytogenetic analysis revealed the specific chromosomal pattern of the Cassandra retrotransposon with prominent clustering at and around 5S rDNA loci. The secondary structure of the Cassandra retroelement RNA is predicted to form super-loops, in which the two LTRs are complementary to each other and can initiate local recombination, leading to the tandem arrays of Cassandra elements. The array structures are conserved for Cassandra retroelements of different species. We speculate that recombination events similar to those of 5S rRNA genes may explain the wide variation in Cassandra copy number. Likewise, the organization of 5S rRNA gene sequences is very variable in flowering plants; part of what is taken for 5S gene copy variation may be variation in Cassandra number. The role of the Cassandra 5S sequences remains to be established.


Genome ◽  
1997 ◽  
Vol 40 (2) ◽  
pp. 171-175 ◽  
Author(s):  
J. Schondelmaier ◽  
T. Schmidt ◽  
C. Jung ◽  
J. S. Heslop-Harrison

A digoxigenin-labelled 5S rDNA probe containing the 5S rRNA gene and the adjacent intergenic spacer was used for in situ hybridization to metaphase and interphase chromosomes of a trisomic stock from sugar beet (Beta vulgaris L.). Three chromosomes of primary trisomic line IV (T. Butterfass. Z. Bot. 52: 46–77. 1964) revealed signals close to the centromeres. Polymorphisms of 5S rDNA repeats in a segregating population were used to map genetically the 5S rRNA genes within a cluster of markers in linkage group II of sugar beet. The concentration of genetic markers around the centromere presumably reflects the suppressed recombination frequency in centromeric regions. The correlation of physical and genetic data allowed the assignment of a linkage group to sugar beet chromosome IV according to line IV of the primary trisomics.Key words: Beta vulgaris, sugar beet, 5S rRNA, in situ hybridization, RFLPs, trisomics.


Genome ◽  
1996 ◽  
Vol 39 (1) ◽  
pp. 140-149 ◽  
Author(s):  
Bernard R. Baum ◽  
Douglas A. Johnson

5S rRNA genes from several accessions of Hordeum spontaneum and Hordeum bulbosum, wild relatives of cultivated barley, Hordeum vulgare, have been amplified by the polymerase chain reaction, cloned, and sequenced. Evaluation of aligned sequences along with principal coordinate analysis demonstrates that the two classes of 5S rDNA sequences found in cultivated barley, and subclasses (groups) of these sequences, can also be found in its closest wild relatives. The two classes of units, formerly categorized as containing short or long 5S rDNA repeats, are distinguishable by the presence or absence of a TAG repeating unit. Sequence comparisons of individual clones (units) isolated from different species have allowed us to confirm that orthology exists for several groups. This demonstration of orthologous groups suggests that the 5S rDNA sequence may be useful for further phylogenetic analysis in the genus Hordeum and possibly in the Triticeae. Key words : 5S rDNA, barley, sequence diversity, phylogenetic analysis.


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