Fluorescent Staining and Fluorescence in situ Hybridization of rDNA of Chromosomes in Pear (Pyrus spp.)

Abstract

Fluorescent banding patterns of pear chromosomes were determined from samples taken from root tips of openpollinated seedlings of Pyrus pyrifolia (Burm. F) Nakai (Japanese pear), P. calleryana Decne. (Callery pear), P. pyrifolia × P. ussuriensis var. aromatica (a hybrid of Japanese pear and Iwateyamanashi), and P. mikawana Koidz. (Toyotomi Nashi). All accessions used in this study had 2n = 34 chromosomes. Chromomycin A 3 (CMA)-positive (+) bands were observed in telomeric positions of four chromosomes in all accessions. 4'-6-diamidino-2-phenylindole (DAPI)-negative bands (−) corresponded with CMA+ bands. Fluorescence in situ hybridization (FISH) was conducted using open-pollinated seedlings of 'Osa Gold' (Pyrus pyrifolia) and Toyotomi Nashi (P. mikawana) as materials. Four out of six 18S-5.8S-25S ribosomal RNA gene (rDNA) sites corresponded with CMA+/DAPI− bands. The 5S rDNA sites were detected in centromeric positions of two chromosomes. Two centromeric 5S rDNA and six telomeric 18S-5.8S-25S rDNA sites were located on different chromosomes as determined from the results of multi-color FISH.

Enzyme Maceration, Fluorescent Staining, and FISH of rDNA of Pineapple (<i>Ananas comosus</i> (L.) Merr.) Chromosomes

“…The 18S-5.8S-25S rDNA sites corresponded with CMA+/ DAPI− bands. This agrees with the results of peach and pear, which showed CMA+ bands that corresponded with 18S-5.8S-25S rDNA sites (Yamamoto et al, 1999b(Yamamoto et al, , 2012. These results indicate that 18S-5.8S-25S rDNA sites of pineapple are in a region with a high GC content (Schweizer, 1976).…”

“…These results indicate that 18S-5.8S-25S rDNA sites of pineapple are in a region with a high GC content (Schweizer, 1976). The 18S-5.8S-25S and 5S rDNA sites have been detected in several fruit tree species (Choi et al, 2003;Corredor et al, 2004;De Melo and Guerra, 2003;Pedrosa et al, 2000;Yamamoto et al, 2012) and their detection is useful for chromosome identification and phylogenetic studies. Therefore, the results of the present study are considered to be the first step towards applying chromosome information to these studies in pineapple.…”

Recent Progress on Studies of Chromosome Observation in Deciduous Fruit Trees

“…The 5S rDNA sites were detected in centromeric positions of two chromosomes. Two centromeric 5S rDNA and six telomeric 18S-5.8S-25S rDNA sites were located at different chromosomes, as determined from the results of McFISH (Yamamoto et al, 2012) (Fig. 5).…”

“…The six signal sites were located in telomeric regions of the six chromosomes. Four CMA+/DAPI− bands corresponded with 18S-5.8S-25S rDNA sites (Yamamoto et al, 2010b(Yamamoto et al, , 2012 (Fig. 5).…”

“…This multi-color FISH (McFISH) should be useful in developing molecular cytogenetics (Mukai, 1996). Table 4 shows a list of FISH studies of deciduous fruit trees (Choi et al, 2003a(Choi et al, , 2003cCorredor et al, 2004;Kim et al, 2011;Maghuly et al, 2010;Minamikawa et al, 2010;Nakao et al, 2005;Schuster et al, 1997;Yamamoto et al, 1999b;2010b;2012). Physical mapping of rDNA genes has been performed in some species, such as Prunus, Malus, Pyrus, Diospyros, and Ginkgo.…”