Limits...
Genome-dependent chromosome dynamics in three successive generations of the allotetraploid Festuca pratensis × Lolium perenne hybrid.

Książczyk T, Zwierzykowska E, Molik K, Taciak M, Krajewski P, Zwierzykowski Z - Protoplasma (2014)

Bottom Line: The results revealed that plants of the three generations share various rDNA loci profiles with chromosome structural changes, possibly as a result of chromosomal inter- and intra-rearrangements.Statistically significant differences between L. perenne and F. pratensis genomes concerned the number of recombined chromosomes without rDNA, and the number of recombined rDNA-bearing chromosomal arms of marked chromosomes, showing a tendency of F. pratensis genome-like chromosomes to be less stable, compared with L. perenne.We postulate a novel genome-dependent range and type of chromosome variation in plants of the F2-F4 generations derived from F. pratensis × L. perenne hybrid.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Stress Biology, Institute of Plant Genetics of the Polish Academy of Sciences, Strzeszyńska 34, 60-479, Poznań, Poland, tksi@igr.poznan.pl.

ABSTRACT
We focus on the identification of complete and recombined ribosomal DNA-bearing chromosomes, and the dynamics of chromosomal number and position of ribosomal DNA (rDNA) loci in the F2-F4 generations derived from the F1 hybrid of Festuca pratensis Huds. (2n = 4x = 28) × Lolium perenne L. (2n = 4x = 28). Lolium genomic DNA and rRNA genes were mapped by means of genomic and fluorescence in situ hybridization (GISH and FISH). The results revealed that plants of the three generations share various rDNA loci profiles with chromosome structural changes, possibly as a result of chromosomal inter- and intra-rearrangements. We observed an asymmetrical variation in the number of recombinant arms with and without rDNA loci between parental genomes. The Lolium genome was more affected by rearrangements in arms with rDNA loci, while Festuca was more affected in arms without them. Statistically significant differences between L. perenne and F. pratensis genomes concerned the number of recombined chromosomes without rDNA, and the number of recombined rDNA-bearing chromosomal arms of marked chromosomes, showing a tendency of F. pratensis genome-like chromosomes to be less stable, compared with L. perenne. We postulate a novel genome-dependent range and type of chromosome variation in plants of the F2-F4 generations derived from F. pratensis × L. perenne hybrid.

No MeSH data available.


Related in: MedlinePlus

rDNA-FISH/GISH of known Lp and Fp rDNA-bearing chromosomes in plants of the F2-F4 generations derived from F. pratensis (4x) × L. perenne (4x) hybrid. Data of FISH/GISH analyses of base rDNA-bearing chromosomes from the F1 generation were published previously (Książczyk et al. 2010). The color of the chromosome band label indicates the fluorochrome used in each experiment (pink for rhodamine; 5S rDNA, green and green/yellow for FITC; 35S rDNA and Lp genomic DNA, respectively). FISH painted chromosomes were counterstained with DAPI (blue), while GISH ones were counterstained with propidium iodide (red)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4491343&req=5

Fig2: rDNA-FISH/GISH of known Lp and Fp rDNA-bearing chromosomes in plants of the F2-F4 generations derived from F. pratensis (4x) × L. perenne (4x) hybrid. Data of FISH/GISH analyses of base rDNA-bearing chromosomes from the F1 generation were published previously (Książczyk et al. 2010). The color of the chromosome band label indicates the fluorochrome used in each experiment (pink for rhodamine; 5S rDNA, green and green/yellow for FITC; 35S rDNA and Lp genomic DNA, respectively). FISH painted chromosomes were counterstained with DAPI (blue), while GISH ones were counterstained with propidium iodide (red)

Mentions: Sixty-five Lp homologues of chromosome 3 were observed in Fp × Lp plants (Table 1), and 48 of these chromosomes did not undergo numerical changes, while among 157 Lp homologues of chromosomes 1, 2, and 7, only 16 Lp rDNA-carrying ones were stable, and their number was consistent with the hypothetical model (Online Resource S1). In the F2-F4 plants studied, among 63 homologues of Fp chromosome 2, and 54 homologues of Fp chromosome 3, no numerical changes were noted in 48 and 50 homologues, respectively. In the F2 generation, Lp homologue(s) of chromosome 3 was rarely involved in recombination, showing rearrangement (only one case; Figs. 1a, b and 2), while no Fp homologues of chromosomes 2 and 3 were found to be rearranged. In the F3 generation, the Lp homologue of chromosome 3 and Fp homologues of chromosomes 2 and 3 were involved in recombination, showing rearrangements (14 cases; Fig. 2), and, in turn, in the F4 generation, the Lp homologue of chromosome 3 and Fp homologues of chromosomes 2 and 3 (Fig. 1e, f) were also recombined (21 cases; Fig. 2). Over the generations, the variation in the number of rDNA-carrying chromosomes of both parental genomes seemed to be asymmetrical and genome-dependent (Table 1); statistically significant difference for rDNA-bearing chromosomes between generations was found for Fp chromosome 2 (35S rDNA) at P = 0.022.Fig. 1


Genome-dependent chromosome dynamics in three successive generations of the allotetraploid Festuca pratensis × Lolium perenne hybrid.

Książczyk T, Zwierzykowska E, Molik K, Taciak M, Krajewski P, Zwierzykowski Z - Protoplasma (2014)

rDNA-FISH/GISH of known Lp and Fp rDNA-bearing chromosomes in plants of the F2-F4 generations derived from F. pratensis (4x) × L. perenne (4x) hybrid. Data of FISH/GISH analyses of base rDNA-bearing chromosomes from the F1 generation were published previously (Książczyk et al. 2010). The color of the chromosome band label indicates the fluorochrome used in each experiment (pink for rhodamine; 5S rDNA, green and green/yellow for FITC; 35S rDNA and Lp genomic DNA, respectively). FISH painted chromosomes were counterstained with DAPI (blue), while GISH ones were counterstained with propidium iodide (red)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4491343&req=5

Fig2: rDNA-FISH/GISH of known Lp and Fp rDNA-bearing chromosomes in plants of the F2-F4 generations derived from F. pratensis (4x) × L. perenne (4x) hybrid. Data of FISH/GISH analyses of base rDNA-bearing chromosomes from the F1 generation were published previously (Książczyk et al. 2010). The color of the chromosome band label indicates the fluorochrome used in each experiment (pink for rhodamine; 5S rDNA, green and green/yellow for FITC; 35S rDNA and Lp genomic DNA, respectively). FISH painted chromosomes were counterstained with DAPI (blue), while GISH ones were counterstained with propidium iodide (red)
Mentions: Sixty-five Lp homologues of chromosome 3 were observed in Fp × Lp plants (Table 1), and 48 of these chromosomes did not undergo numerical changes, while among 157 Lp homologues of chromosomes 1, 2, and 7, only 16 Lp rDNA-carrying ones were stable, and their number was consistent with the hypothetical model (Online Resource S1). In the F2-F4 plants studied, among 63 homologues of Fp chromosome 2, and 54 homologues of Fp chromosome 3, no numerical changes were noted in 48 and 50 homologues, respectively. In the F2 generation, Lp homologue(s) of chromosome 3 was rarely involved in recombination, showing rearrangement (only one case; Figs. 1a, b and 2), while no Fp homologues of chromosomes 2 and 3 were found to be rearranged. In the F3 generation, the Lp homologue of chromosome 3 and Fp homologues of chromosomes 2 and 3 were involved in recombination, showing rearrangements (14 cases; Fig. 2), and, in turn, in the F4 generation, the Lp homologue of chromosome 3 and Fp homologues of chromosomes 2 and 3 (Fig. 1e, f) were also recombined (21 cases; Fig. 2). Over the generations, the variation in the number of rDNA-carrying chromosomes of both parental genomes seemed to be asymmetrical and genome-dependent (Table 1); statistically significant difference for rDNA-bearing chromosomes between generations was found for Fp chromosome 2 (35S rDNA) at P = 0.022.Fig. 1

Bottom Line: The results revealed that plants of the three generations share various rDNA loci profiles with chromosome structural changes, possibly as a result of chromosomal inter- and intra-rearrangements.Statistically significant differences between L. perenne and F. pratensis genomes concerned the number of recombined chromosomes without rDNA, and the number of recombined rDNA-bearing chromosomal arms of marked chromosomes, showing a tendency of F. pratensis genome-like chromosomes to be less stable, compared with L. perenne.We postulate a novel genome-dependent range and type of chromosome variation in plants of the F2-F4 generations derived from F. pratensis × L. perenne hybrid.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Stress Biology, Institute of Plant Genetics of the Polish Academy of Sciences, Strzeszyńska 34, 60-479, Poznań, Poland, tksi@igr.poznan.pl.

ABSTRACT
We focus on the identification of complete and recombined ribosomal DNA-bearing chromosomes, and the dynamics of chromosomal number and position of ribosomal DNA (rDNA) loci in the F2-F4 generations derived from the F1 hybrid of Festuca pratensis Huds. (2n = 4x = 28) × Lolium perenne L. (2n = 4x = 28). Lolium genomic DNA and rRNA genes were mapped by means of genomic and fluorescence in situ hybridization (GISH and FISH). The results revealed that plants of the three generations share various rDNA loci profiles with chromosome structural changes, possibly as a result of chromosomal inter- and intra-rearrangements. We observed an asymmetrical variation in the number of recombinant arms with and without rDNA loci between parental genomes. The Lolium genome was more affected by rearrangements in arms with rDNA loci, while Festuca was more affected in arms without them. Statistically significant differences between L. perenne and F. pratensis genomes concerned the number of recombined chromosomes without rDNA, and the number of recombined rDNA-bearing chromosomal arms of marked chromosomes, showing a tendency of F. pratensis genome-like chromosomes to be less stable, compared with L. perenne. We postulate a novel genome-dependent range and type of chromosome variation in plants of the F2-F4 generations derived from F. pratensis × L. perenne hybrid.

No MeSH data available.


Related in: MedlinePlus