Physical mapping of the B-hordein loci on barley chromosome 5 by in situ hybridization

Genome ◽  
1989 ◽  
Vol 32 (5) ◽  
pp. 925-929 ◽  
Author(s):  
Melody Clark ◽  
Angela Karp ◽  
Simon Archer

Physical mapping of the B-hordein genes in barley (Hordeum vulgare cv. Betzes) was achieved by in situ hybridization of a biotin-labelled B-hordein cRNA probe to chromosome spreads. Lines trisomic for chromosome 5 showed up to 3 signals on interphase nuclei, while no more than 2 signals were observed in normal diploids. An enzyme pretreatment, which produced broken cells, increased the frequency of signal detection. A clear signal was observed on 23% of interphase nuclei and 0.025% of metaphase spreads. The B-hordein genes mapped to 46% of the distance from the centromere on the short arm of chromosome 5. These results are discussed in relation to the barley genetic map and to previous reports of in situ hybridization of low-copy and unique-copy genes in plants.Key words: in situ hybridization, Hordeum vulgare, B-hordein genes, genetic map.

Genome ◽  
2004 ◽  
Vol 47 (1) ◽  
pp. 179-189 ◽  
Author(s):  
J L Stephens ◽  
S E Brown ◽  
N L.V Lapitan ◽  
D L Knudson

The primary objective of this study was to elucidate gene organization and to integrate the genetic linkage map for barley (Hordeum vulgare L.) with a physical map using ultrasensitive fluorescence in situ hybridization (FISH) techniques for detecting signals from restriction fragment length polymorphism (RFLP) clones. In the process, a single landmark plasmid, p18S5Shor, was constructed that identified and oriented all seven of the chromosome pairs. Plasmid p18S5Shor was used in all hybridizations. Fourteen cDNA probes selected from the linkage map for barley H. vulgare 'Steptoe' × H. vulgare 'Morex' (Kleinhofs et al. 1993) were mapped using an indirect tyramide signal amplification technique and assigned to a physical location on one or more chromosomes. The haploid barley genome is large and a complete physical map of the genome is not yet available; however, it was possible to integrate the linkage map and the physical locations of these cDNAs. An estimate of the ratio of base pairs to centimorgans was an average of 1.5 Mb/cM in the distal portions of the chromosome arms and 89 Mb/cM near the centromere. Furthermore, while it appears that the current linkage maps are well covered with markers along the length of each arm, the physical map showed that there are large areas of the genome that have yet to be mapped.Key words: Hordeum vulgare, barley, physical mapping, FISH, cDNA, genetics, linkage, chromosome, BACs.


Genome ◽  
1993 ◽  
Vol 36 (3) ◽  
pp. 517-523 ◽  
Author(s):  
I. J. Leitch ◽  
J. S. Heslop-Harrison

The 5S rDNA sequences have been mapped on four pairs of barley (Hordeum vulgare L.) chromosomes using in situ hybridization and barley monotelotrisomic lines. The 5S rDNA sequences are located, genetically and physically, on the short arm of chromosome 1 (7I) and the long arms of chromosomes 2 (2I) and 3 (3I). The 5S rDNA sequence is also located on the physically long arm of chromosome 4 (4I). Only one site on chromosome 2(2I) has previously been reported. The characteristic locations of the 5S rDNA sequences make them useful as molecular markers to identify each barley chromosome. The physical position of the low-copy α-amylase-2 gene was determined using in situ hybridization; the location of this gene on the long arm of chromosome 1 (7I) was confirmed by reprobing the same preparation with the 5S rDNA probe. The results show that there is a discrepancy between the physical and genetic position of the α-amylase-2 gene.Key words: genetic mapping, physical mapping, barley, mapping, 5S DNA, α-amylase, in situ hybridization.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Liuyang Fu ◽  
Qian Wang ◽  
Lina Li ◽  
Tao Lang ◽  
Junjia Guo ◽  
...  

Abstract Background Chromosomal variants play important roles in crop breeding and genetic research. The development of single-stranded oligonucleotide (oligo) probes simplifies the process of fluorescence in situ hybridization (FISH) and facilitates chromosomal identification in many species. Genome sequencing provides rich resources for the development of oligo probes. However, little progress has been made in peanut due to the lack of efficient chromosomal markers. Until now, the identification of chromosomal variants in peanut has remained a challenge. Results A total of 114 new oligo probes were developed based on the genome-wide tandem repeats (TRs) identified from the reference sequences of the peanut variety Tifrunner (AABB, 2n = 4x = 40) and the diploid species Arachis ipaensis (BB, 2n = 2x = 20). These oligo probes were classified into 28 types based on their positions and overlapping signals in chromosomes. For each type, a representative oligo was selected and modified with green fluorescein 6-carboxyfluorescein (FAM) or red fluorescein 6-carboxytetramethylrhodamine (TAMRA). Two cocktails, Multiplex #3 and Multiplex #4, were developed by pooling the fluorophore conjugated probes. Multiplex #3 included FAM-modified oligo TIF-439, oligo TIF-185-1, oligo TIF-134-3 and oligo TIF-165. Multiplex #4 included TAMRA-modified oligo Ipa-1162, oligo Ipa-1137, oligo DP-1 and oligo DP-5. Each cocktail enabled the establishment of a genome map-based karyotype after sequential FISH/genomic in situ hybridization (GISH) and in silico mapping. Furthermore, we identified 14 chromosomal variants of the peanut induced by radiation exposure. A total of 28 representative probes were further chromosomally mapped onto the new karyotype. Among the probes, eight were mapped in the secondary constrictions, intercalary and terminal regions; four were B genome-specific; one was chromosome-specific; and the remaining 15 were extensively mapped in the pericentric regions of the chromosomes. Conclusions The development of new oligo probes provides an effective set of tools which can be used to distinguish the various chromosomes of the peanut. Physical mapping by FISH reveals the genomic organization of repetitive oligos in peanut chromosomes. A genome map-based karyotype was established and used for the identification of chromosome variations in peanut following comparisons with their reference sequence positions.


1991 ◽  
Vol 112 (4) ◽  
pp. 1480-1483 ◽  
Author(s):  
S. G. Vorsanova ◽  
Yu. B. Yurov ◽  
G. V. Deryagin ◽  
I. V. Solov'ev ◽  
G. A. Bytenskaya

1998 ◽  
Vol 89 (4) ◽  
pp. 366-370 ◽  
Author(s):  
G Butnaru ◽  
J Chen ◽  
P Goicoechea ◽  
JP Gustafson

Genome ◽  
2001 ◽  
Vol 44 (3) ◽  
pp. 401-412 ◽  
Author(s):  
X -F. Ma ◽  
K Ross ◽  
J P Gustafson

Using wheat ditelosomic lines and in situ hybridization of biotin-labelled DNA probes, 18 restriction fragment length polymorphism (RFLP) markers were physically located on homoeologous groups 1 and 3 chromosomes of wheat. Most of the markers hybridized to chromosome arms in a physical order concordant with the genetic maps. A majority of the markers studied were clustered in non-C-banded, distal euchromatic areas, indicating the presence of recombination hot spots and cold spots in those regions. However, on 1BS the markers were well dispersed, which could be due to the abundance of heterochromatin throughout the arm. An inversion between Xpsr653 and Xpsr953 was observed on 1AL. One new Xpsr688 locus, approximately 20–26% from the centromere, was found on 1AS and 1BS. The physical location of Xpsr170 on group 3 chromosomes probably represents an alternative to the loci on the genetic map. Finally, Xpsr313 was mapped to two physical loci on 1DL. Five markers were located to bins consistent with the deletion-based physical maps.Key words: wheat, physical mapping, in situ hybridization.


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