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FISH and GISH analysis of Brassica genomes

100%

Hasterok R. , Ksiazczyk T. , Wolny E. , Maluszynska J.

Acta Biologica Cracoviensia. Series Botanica

2005

tom 47

nr 1

Fluorescence and genomic in situ hybridization (FISH and GISH) methods were used for discrimination of Brassica genomes. The three diploid and three allotetraploid species of Brassica, known as the "U-triangle," represent an attractive model for molecular and cytologieal analysis of genome changes during phylogeny in the genus Brassica. The use of genomic DNA probes enabled unambiguous discrimination of the ancestral genomes in B. juncea and B. carinata, and was only partially successful in B. napus. GISH signals in all genomes were localized predominantly in pericentromeric regions of chromosomes. Simultaneous application of genomic and ribosomal DNA probes in multicolor GISH and FISH allowed identification of a significant number of chromosomes in the B. juncea complement. The study also revealed that species of Brassica possess Arabidopsis-type telomeric repeats which in all genomes occupied exclusively terminal, that is, telomeric, locations of chromosomes.

Molecular cytogenetic analysis of genome structure in Chenopodium album complex

100%

Kolano B. , Siwinska D. , Maluszynska J.

Seria Biologiczna. Uniwersytet im. Adama Mickiewicza w Poznaniu

2005

tom 72

Intraspecific polymorphism of ribosomal DNA loci number and morphology in Brachypodium pinnatum and Brachypodium sylvaticum

80%

Breda E. , Wolny E. , Hasterok R.

Cellular and Molecular Biology Letters

2012

tom 17

nr 4

The genus Brachypodium has become the target of extensive cytomolecular studies since one of its representatives, B. distachyon, has been accepted as a model plant for temperate cereals and forage grasses. Recent preliminary studies suggested that intraspecific rDNA polymorphism can occur in at least two members of the genus, B. sylvaticum and B. pinnatum, so the aim of this study was to further analyse this phenomenon. FISH with 25S rDNA and 5S rDNA probes was performed on somatic metaphase chromosomes, supplemented by the silver staining technique which distinguishes transcriptionally active from inactive 18S-5.8S-25S rDNA loci. The number, size and chromosomal distribution of 5S rDNA loci were very constant: two loci were invariably observed in all studied diploid accessions of both species, while four 5S rDNA loci were present in the tetraploid B. pinnatum. In contrast to 5S rDNA loci, those of the 35S rDNA were more variable. Two or three loci were observed in the diploid B. pinnatum and four in tetraploid accessions. In chromosome complements of B. sylvaticum accessions from two to six 35S rDNA sites were detected. Regardless of total rDNA locus number, only two were transcriptionally active in diploid accessions of both species, while two or four were active in the tetraploid B. pinnatum. Additionally, the fluorescent CMA/DAPI banding method was used to identify the relation between rDNA sites and CMA+ bands. It was revealed that the number and chromosomal distribution of CMA+ bands are in congruence only with 35S rDNA loci which gave strong FISH signals.

Variability of ribosomal DNA sites in Festuca pratensis, Lolium perenne, and their intergeneric hybrids, revealed by FISH and GISH

80%

Ksiazczyk T. , Taciak M. , Zwierzykowski Z.

Journal of Applied Genetics

2010

tom 51

nr 4

This study focuses on the variability of chromosomal location and number of ribosomal DNA (rDNA) sites in some diploid and autotetraploid Festuca pratensis and Lolium perenne cultivars, as well as on identification of rDNA-bearing chromosomes in their triploid and tetraploid F. pratensis × L. perenne hybrids. The rDNA loci were mapped using fluorescence in situ hybridization (FISH) with 5S and 25S rDNA probes, and the origin of parental genomes was verified by genomic in situ hybridization (GISH) with L. perenne genomic DNA as a probe, and F. pratensis genomic DNA as a block. FISH detected variation in the number and chromosomal location of both 5S and 45S rDNA sites. In F. pratensis mostly additional signals of 5S rDNA loci occurred, as compared with standard F. pratensis karyotypes. Losses of 45S rDNA loci were more frequent in L. perenne cultivars and intergeneric hybrids. Comparison of the F. pratensis and L. perenne genomes approved a higher number of rDNA sites as well as variation in chromosomal rDNA location in L. perenne. A greater instability of F. pratensis-genome-like and L. perenne-genome-like chromosomes in tetraploid hybrids was revealed, indicating gains and losses of rDNA loci, respectively. Our data indicate that the rDNA loci physically mapped on chromosomes 2 and 3 in F. pratensis and on chromosome 3 in L. perenne are useful markers for these chromosomes in intergeneric Festuca × Lolium hybrids.