title: High resolution physical mapping of single gene fragments on pachytene chromosome 4 and 7 of Rosa.
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.
authors.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.|Center of Molecular Biotechnology, Russian State Agrarian University - Moscow Timiryazev Agricultural Academy, Listvennichnaya Alleya 5, 127550, Moscow, Russia. kirovez@gmail.com.|Plant Sciences Unit, Applied Genetics and Breeding, Institute for Agricultural and Fisheries Research (ILVO), Caritasstraat 21, 9090, Melle, Belgium. kirovez@gmail.com.
authors.forename: Ilya V
authors.initials: IV
authors.lastname: Kirov
authors.affiliation: Plant Sciences Unit, Applied Genetics and Breeding, Institute for Agricultural and Fisheries Research (ILVO), Caritasstraat 21, 9090, Melle, Belgium. Katrijn.Vanlaere@ilvo.vlaanderen.be.
authors.forename: Katrijn
authors.initials: K
authors.lastname: Van Laere
authors.affiliation: Department of Genetics, Biotechnology, Plant Breeding and Seed Science, Russian State Agrarian University - Moscow Timiryazev Agricultural Academy, Timiryazevskay str.49, 127550, Moscow, Russia. ludmila.khrustaleva19@gmail.com.|Center of Molecular Biotechnology, Russian State Agrarian University - Moscow Timiryazev Agricultural Academy, Listvennichnaya Alleya 5, 127550, Moscow, Russia. ludmila.khrustaleva19@gmail.com.
authors.forename: Ludmila I
authors.initials: LI
authors.lastname: Khrustaleva
mesh_terms: D032461:Chromosomes, Plant; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D049471:Pachytene Stage; D020161:Physical Chromosome Mapping; D027826:Rosa / Q000235:genetics*