scholarly journals Defining the Deletion Size in Williams-Beuren Syndrome by Fluorescent In Situ Hybridization with Bacterial Artificial Chromosomes

Author(s):  
Audrey Basinko ◽  
Nathalie Douet-Guilbert ◽  
Severine Audebert-Bellanger ◽  
Philippe Parent ◽  
Clemence Chabay-Vichot ◽  
...  
Genome ◽  
1997 ◽  
Vol 40 (4) ◽  
pp. 475-478 ◽  
Author(s):  
Martha I. Gómez ◽  
M. Nurul Islam-Faridi ◽  
Sung-Sick Woo ◽  
Don Czeschin Jr. ◽  
Michael S. Zwick ◽  
...  

Fluorescence in situ hybridization (FISH) of a 205 kb Sorghum bicolor bacterial artificial chromosome (BAC) containing a sequence complementary to maize sh2 cDNA produced a large pair of FISH signals at one end of a midsize metacentric chromosome of S. bicolor. Three pairs of signals were observed in metaphase spreads of chromosomes of a sorghum plant containing an extra copy of one arm of the sorghum chromosome arbitrarily designated with the letter D. Therefore, the sequence cloned in this BAC must reside in the arm of chromosome D represented by this monotelosome. This demonstrates a novel procedure for physically mapping cloned genes or other single-copy sequences by FISH, sh2 in this case, by using BACs containing their complementary sequences. The results reported herein suggest homology, at least in part, between one arm of chromosome D in sorghum and the long arm of chromosome 3 in maize.Key words: sorghum, maize, shrunken locus, physical mapping, fluorescence in situ hybridization, bacterial artificial chromosomes.


Genome ◽  
2004 ◽  
Vol 47 (4) ◽  
pp. 764-768 ◽  
Author(s):  
Janice Pagel ◽  
Jason G Walling ◽  
Nevin D Young ◽  
Randy C Shoemaker ◽  
Scott A Jackson

Soybean (Glycine max L. Merr.) is presumed to be an ancient polyploid based on chromosome number and multiple RFLP fragments in genetic mapping. Direct cytogenetic observation of duplicated regions within the soybean genome has not heretofore been reported. Employing flourescence in situ hybridization (FISH) of genetically anchored bacterial artificial chromosomes (BACs) in soybean, we were able to observe that the distal ends of molecular linkage group E had duplicated regions on linkage groups A2 and B2. Further, using fiber-FISH, it was possible to measure the molecular size and organization of one of the duplicated regions. As FISH did not require repetitive DNA for blocking fluorescence signals, we assume that the 200-kb genome region is relatively low in repetitive sequences. This observation, along with the observation that the BACs are located in distal euchromatin regions, has implications for genome structure/evolution and the approach used to sequence the soybean genome.Key words: soybean, genome evolution, FISH, chromosomes, physical mapping.


Genetics ◽  
1993 ◽  
Vol 134 (1) ◽  
pp. 211-219
Author(s):  
D G Albertson

Abstract A scheme for rapidly mapping chromosome rearrangements relative to the physical map of Caenorhabditis elegans is described that is based on hybridization patterns of cloned DNA on meiotic nuclei, as visualized by fluorescent in situ hybridization. From the nearly complete physical map, DNA clones, in yeast artificial chromosomes (YACs), spanning the rearrangement breakpoint were selected. The purified YAC DNAs were first amplified by degenerate oligonucleotide-primed polymerase chain reaction, then reamplified to incorporate fluorescein dUTP or rhodamine dUTP. The site of hybridization was visualized directly (without the use of antibodies) on meiotic bivalents. This allows chromosome rearrangements to be mapped readily if the duplicated, deficient or translocated regions do not pair with a normal homologous region, because the site or sites of hybridization of the probe on meiotic prophase nuclei will be spatially distinct. The pattern, or number, of hybridization signals from probes from within, or adjacent to, the rearranged region of the genome can be predicted from the genetic constitution of the strain. Characterization of the physical extent of the genetically mapped rearrangements places genetic landmarks on the physical map, and so provides linkage between the two types of map.


Genome ◽  
2014 ◽  
Vol 57 (11/12) ◽  
pp. 609-620 ◽  
Author(s):  
Radim J. Vašut ◽  
Kitty Vijverberg ◽  
Peter J. van Dijk ◽  
Hans de Jong

Apomixis in dandelions (Taraxacum: Asteraceae) is encoded by two unlinked dominant loci and a third yet undefined genetic factor: diplosporous omission of meiosis (DIPLOSPOROUS, DIP), parthenogenetic embryo development (PARTHENOGENESIS, PAR), and autonomous endosperm formation, respectively. In this study, we determined the chromosomal position of the DIP locus in Taraxacum by using fluorescent in situ hybridization (FISH) with bacterial artificial chromosomes (BACs) that genetically map within 1.2–0.2 cM of DIP. The BACs showed dispersed fluorescent signals, except for S4-BAC 83 that displayed strong unique signals as well. Under stringent blocking of repeats by C0t-DNA fragments, only a few fluorescent foci restricted to defined chromosome regions remained, including one on the nucleolus organizer region (NOR) chromosomes that contains the 45S rDNAs. FISH with S4-BAC 83 alone and optimal blocking showed discrete foci in the middle of the long arm of one of the NOR chromosomes only in triploid and tetraploid diplosporous dandelions, while signals in sexual diploids were lacking. This agrees with the genetic model of a single dose, dominant DIP allele, absent in sexuals. The length of the DIP region is estimated to cover a region of 1–10 Mb. FISH in various accessions of Taraxacum and the apomictic sister species Chondrilla juncea, confirmed the chromosomal position of DIP within Taraxacum but not outside the genus. Our results endorse that, compared to other model apomictic species, expressing either diplospory or apospory, the genome of Taraxacum shows a more similar and less diverged chromosome structure at the DIP locus. The different levels of allele sequence divergence at apomeiosis loci may reflect different terms of asexual reproduction. The association of apomeiosis loci with repetitiveness, dispersed repeats, and retrotransposons commonly observed in apomictic species may imply a functional role of these shared features in apomictic reproduction, as is discussed.


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