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High resolution physical mapping of single gene fragments on pachytene chromosome 4 and 7 of Rosa.

Kirov IV, Van Laere K, Khrustaleva LI - BMC Genet. (2015)

Bottom Line: Using high resolution Tyramide-FISH and multicolor Tyramide-FISH, 7 genes (1.7-3 kb) were successfully mapped on pachytene chromosomes 4 and 7 of Rosa wichurana.Comparison of the gene order between Rosa wichurana and Fragaria vesca revealed a poor collinearity for chromosome 7, but a perfect collinearity for chromosome 4.Application of Tyramide-FISH on pachytene chromosomes allowed the mapping resolution to be increased up to 20 times compared to mitotic metaphase chromosomes.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetics, Biotechnology, Plant Breeding and Seed Science, Russian State Agrarian University - Moscow Timiryazev Agricultural Academy, Timiryazevskay str.49, 127550, Moscow, Russia. kirovez@gmail.com.

ABSTRACT

Background: Rosaceae is a family containing many economically important fruit and ornamental species. Although fluorescence in situ hybridization (FISH)-based physical mapping of plant genomes is a valuable tool for map-based cloning, comparative genomics and evolutionary studies, no studies using high resolution physical mapping have been performed in this family. Previously we proved that physical mapping of single-copy genes as small as 1.1 kb is possible on mitotic metaphase chromosomes of Rosa wichurana using Tyramide-FISH. In this study we aimed to further improve the physical map of Rosa wichurana by applying high resolution FISH to pachytene chromosomes.

Results: Using high resolution Tyramide-FISH and multicolor Tyramide-FISH, 7 genes (1.7-3 kb) were successfully mapped on pachytene chromosomes 4 and 7 of Rosa wichurana. Additionally, by using multicolor Tyramide-FISH three closely located genes were simultaneously visualized on chromosome 7. A detailed map of heterochromatine/euchromatine patterns of chromosome 4 and 7 was developed with indication of the physical position of these 7 genes. Comparison of the gene order between Rosa wichurana and Fragaria vesca revealed a poor collinearity for chromosome 7, but a perfect collinearity for chromosome 4.

Conclusions: High resolution physical mapping of short probes on pachytene chromosomes of Rosa wichurana was successfully performed for the first time. Application of Tyramide-FISH on pachytene chromosomes allowed the mapping resolution to be increased up to 20 times compared to mitotic metaphase chromosomes. High resolution Tyramide-FISH and multicolor Tyramide-FISH might become useful tools for further physical mapping of single-copy genes and for the integration of physical and genetic maps of Rosa wichurana and other members of the Rosaceae.

No MeSH data available.


Physical location of 7 target genes on R. wichurana chromosome 7 (RwChr7, left) and 4 (RwChr4, right) versus Fragaria vesca pseudochromosomes 6 (FvChr6) and 7 (FvChr6), correspondently. Signals are shown on digitally straightened pachytene chromosomes and on an ideogram of R. wichurana and compared with pseudochromosome 6 (FvChr6) and 7 (FvChr7) of the F. vesca genome sequence
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Fig4: Physical location of 7 target genes on R. wichurana chromosome 7 (RwChr7, left) and 4 (RwChr4, right) versus Fragaria vesca pseudochromosomes 6 (FvChr6) and 7 (FvChr6), correspondently. Signals are shown on digitally straightened pachytene chromosomes and on an ideogram of R. wichurana and compared with pseudochromosome 6 (FvChr6) and 7 (FvChr7) of the F. vesca genome sequence

Mentions: Because PAL and MLO2 are very closely located on chromosome 7, Tyramide-FISH with PAL and MLO2 resulted in one large signal. Therefore, to determine the order of PAL and MLO2 genes on chromosome 7, multicolor Tyramide-FISH was applied (Fig. 3f). Two-color Tyramide-FISH revealed the order of MLO2, PAL and MGM genes on the same chromosome. In 58 % of the observed pachytene cells (n = 17) closely located red (PAL) and green (MLO2) signals were observed, while the red and green signals in the other 42 % of pachytene cells partially overlapped. These results suggest that the distance between MLO2 and PAL genes is on the border of the spatial resolution of Tyramide-FISH on pachytene chromosome of R. wichurana. Based on the length of the pachytene bivalents carrying non-overlapped signals (41 ± 1.5 μm), the relative length of the mitotic chromosome 7 (10.0 ± 0.1 %; Kirov et al. [47]), the genome size for R. wichurana (562 Mb/1C, [52]) and 0.2 μm - resolution limit for light microscope, we may calculate the physical distance between the MLO2 and PAL genes which is about 270 kb. An overview of the genes located on chromosome 4 and chromosome 7 and their order is shown in Fig. 4.Fig. 4


High resolution physical mapping of single gene fragments on pachytene chromosome 4 and 7 of Rosa.

Kirov IV, Van Laere K, Khrustaleva LI - BMC Genet. (2015)

Physical location of 7 target genes on R. wichurana chromosome 7 (RwChr7, left) and 4 (RwChr4, right) versus Fragaria vesca pseudochromosomes 6 (FvChr6) and 7 (FvChr6), correspondently. Signals are shown on digitally straightened pachytene chromosomes and on an ideogram of R. wichurana and compared with pseudochromosome 6 (FvChr6) and 7 (FvChr7) of the F. vesca genome sequence
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4488978&req=5

Fig4: Physical location of 7 target genes on R. wichurana chromosome 7 (RwChr7, left) and 4 (RwChr4, right) versus Fragaria vesca pseudochromosomes 6 (FvChr6) and 7 (FvChr6), correspondently. Signals are shown on digitally straightened pachytene chromosomes and on an ideogram of R. wichurana and compared with pseudochromosome 6 (FvChr6) and 7 (FvChr7) of the F. vesca genome sequence
Mentions: Because PAL and MLO2 are very closely located on chromosome 7, Tyramide-FISH with PAL and MLO2 resulted in one large signal. Therefore, to determine the order of PAL and MLO2 genes on chromosome 7, multicolor Tyramide-FISH was applied (Fig. 3f). Two-color Tyramide-FISH revealed the order of MLO2, PAL and MGM genes on the same chromosome. In 58 % of the observed pachytene cells (n = 17) closely located red (PAL) and green (MLO2) signals were observed, while the red and green signals in the other 42 % of pachytene cells partially overlapped. These results suggest that the distance between MLO2 and PAL genes is on the border of the spatial resolution of Tyramide-FISH on pachytene chromosome of R. wichurana. Based on the length of the pachytene bivalents carrying non-overlapped signals (41 ± 1.5 μm), the relative length of the mitotic chromosome 7 (10.0 ± 0.1 %; Kirov et al. [47]), the genome size for R. wichurana (562 Mb/1C, [52]) and 0.2 μm - resolution limit for light microscope, we may calculate the physical distance between the MLO2 and PAL genes which is about 270 kb. An overview of the genes located on chromosome 4 and chromosome 7 and their order is shown in Fig. 4.Fig. 4

Bottom Line: Using high resolution Tyramide-FISH and multicolor Tyramide-FISH, 7 genes (1.7-3 kb) were successfully mapped on pachytene chromosomes 4 and 7 of Rosa wichurana.Comparison of the gene order between Rosa wichurana and Fragaria vesca revealed a poor collinearity for chromosome 7, but a perfect collinearity for chromosome 4.Application of Tyramide-FISH on pachytene chromosomes allowed the mapping resolution to be increased up to 20 times compared to mitotic metaphase chromosomes.

View Article: PubMed Central - PubMed

Affiliation: Department of Genetics, Biotechnology, Plant Breeding and Seed Science, Russian State Agrarian University - Moscow Timiryazev Agricultural Academy, Timiryazevskay str.49, 127550, Moscow, Russia. kirovez@gmail.com.

ABSTRACT

Background: Rosaceae is a family containing many economically important fruit and ornamental species. Although fluorescence in situ hybridization (FISH)-based physical mapping of plant genomes is a valuable tool for map-based cloning, comparative genomics and evolutionary studies, no studies using high resolution physical mapping have been performed in this family. Previously we proved that physical mapping of single-copy genes as small as 1.1 kb is possible on mitotic metaphase chromosomes of Rosa wichurana using Tyramide-FISH. In this study we aimed to further improve the physical map of Rosa wichurana by applying high resolution FISH to pachytene chromosomes.

Results: Using high resolution Tyramide-FISH and multicolor Tyramide-FISH, 7 genes (1.7-3 kb) were successfully mapped on pachytene chromosomes 4 and 7 of Rosa wichurana. Additionally, by using multicolor Tyramide-FISH three closely located genes were simultaneously visualized on chromosome 7. A detailed map of heterochromatine/euchromatine patterns of chromosome 4 and 7 was developed with indication of the physical position of these 7 genes. Comparison of the gene order between Rosa wichurana and Fragaria vesca revealed a poor collinearity for chromosome 7, but a perfect collinearity for chromosome 4.

Conclusions: High resolution physical mapping of short probes on pachytene chromosomes of Rosa wichurana was successfully performed for the first time. Application of Tyramide-FISH on pachytene chromosomes allowed the mapping resolution to be increased up to 20 times compared to mitotic metaphase chromosomes. High resolution Tyramide-FISH and multicolor Tyramide-FISH might become useful tools for further physical mapping of single-copy genes and for the integration of physical and genetic maps of Rosa wichurana and other members of the Rosaceae.

No MeSH data available.