Physical location of terminal markers belonging to five linkage groups in maize RFLP map using in situ hybridization

1997 ◽  
Vol 2 (4) ◽  
pp. 496-502
Author(s):  
Mao Ninghui ◽  
Song Yunchun ◽  
Liu Lihua ◽  
Hang Chao ◽  
Yan Chunhong
Genome ◽  
1996 ◽  
Vol 39 (4) ◽  
pp. 784-792 ◽  
Author(s):  
M. Humberto Reyes-Valdés ◽  
Yuanfu Ji ◽  
Charles F. Crane ◽  
M. Nurul Islam-Faridi ◽  
H. James Price ◽  
...  

Chiasmata constitute one of the cornerstones of sexual reproduction in most eukaryotes. They mediate the reciprocal genetic exchange between homologues and are essential to the proper orientation of the homologous centromeres in meiosis I. As markers of recombination, they offer a cytological means of mapping. Rather than trying to accurately count individual chiasmata, we have examined properties of the mathematical relationship between frequencies of nonadorned disomic configurations in meiosis (ring, rods, and univalents) and the probabilities at which arms of the respective chromosomes are chiasmate (one or more chiasma per arm). Numerical analyses indicated that conventionally analyzed bivalents with nonidentified arms yield statistically biased estimates of chiasma probabilities under a broad range of circumstances. We subsequently analyzed estimators derived from adorned configurations with ISH-marked arms, which were found to be statistically far superior, and with no assumptions concerning interference across the centromere. We applied this methodology in the study of chromosomes 16 and 23 of cotton (Gossypium hirsutum), and estimated their arm lengths in centimorgans. The results for chromosome 23, the only one of the two chromosomes with a documented RFLP map, were consistent with the literature. Similar molecular-meiotic configuration analyses can be used for a wide variety of eukaryotic organisms and purposes: for example, providing far more powerful meiotic comparisons of genomes of chromosomes, and a rapid means of evaluating effects on recombination. Key words : meiotic configurations, chiasma frequencies, in situ hybridization, cotton.


Genome ◽  
2002 ◽  
Vol 45 (2) ◽  
pp. 402-412 ◽  
Author(s):  
Jeong-Soon Kim ◽  
Kevin L Childs ◽  
M Nurul Islam-Faridi ◽  
Monica A Menz ◽  
Robert R Klein ◽  
...  

The reliability of genome analysis and proficiency of genetic manipulation are increased by assignment of linkage groups to specific chromosomes, placement of centromeres, and orientation with respect to telomeres. We have endeavored to establish means to enable these steps in sorghum (Sorghum bicolor (L.) Moench), the genome of which contains ca. 780 Mbp spread across n = 10 chromosomes. Our approach relies on fluorescence in situ hybridization (FISH) and integrated structural genomic resources, including large-insert genomic clones in bacterial artificial chromosome (BAC) libraries. To develop robust FISH probes, we selected sorghum BACs by association with molecular markers that map near the ends of linkage groups, in regions inferred to be high in recombination. Overall, we selected 22 BACs that encompass the 10 linkage groups. As a prelude to development of a multiprobe FISH cocktail, we evaluated BAC-derived probes individually and in small groups. Biotin- and digoxygenin-labeled probes were made directly from the BAC clones and hybridized in situ to chromosomes without using suppressive unlabelled C0t-1 DNA. Based on FISH-signal strength and the relative degree of background signal, we judged 19 BAC-derived probes to be satisfactory. Based on their relative position, and collective association with all 10 linkage groups, we chose 17 of the 19 BACs to develop a 17-locus probe cocktail for dual-color detection. FISH of the cocktail allowed simultaneous identification of all 10 chromosomes. The results indicate that linkage and physical maps of sorghum allow facile selection of BAC clones according to position and FISH-signal quality. This capability will enable development of a high-quality molecular cytogenetic map and an integrated genomics system for sorghum, without need of chromosome flow sorting or microdissection. Moreover, transgeneric FISH experiments suggest that the sorghum system might be applicable to other Gramineae.Key words: integrated karyotyping, FISH, sorghum, BAC.


Genetics ◽  
1996 ◽  
Vol 144 (1) ◽  
pp. 279-305 ◽  
Author(s):  
Daniel Vaiman ◽  
Laurent Schibler ◽  
Florence Bourgeois ◽  
Anne Oustry ◽  
Yves Amigues ◽  
...  

Abstract This paper presents a first genetic linkage map of the goat genome. Primers derived from the flanking sequences of 612 bovine, ovine and goat microsatellite markers were gathered and tested for amplification with goat DNA under standardized PCR conditions. This screen made it possible to choose a set of 55 polymorphic markers that can be used in the three species and to define a panel of 223 microsatellites suitable for the goat. Twelve half-sib paternal goat families were then used to build a linkage map of the goat genome. The linkage analysis made it possible to construct a meiotic map covering 2300 cM, i.e., >SO% of the total estimated length of the goat genome. Moreover, eight cosmids containing microsatellites were mapped by fluorescence in situ hybridization in goat and sheep. Together with 11 microsatellite-containing cosmids previously mapped in cattle (and supposing conservation of the banding pattern between this species and the goat) and data from the sheep map, these results made the orientation of 15 linkage groups possible. Furthermore, 12 coding sequences were mapped either genetically or physically, providing useful data for comparative mapping.


Author(s):  
Barbara Trask ◽  
Susan Allen ◽  
Anne Bergmann ◽  
Mari Christensen ◽  
Anne Fertitta ◽  
...  

Using fluorescence in situ hybridization (FISH), the positions of DNA sequences can be discretely marked with a fluorescent spot. The efficiency of marking DNA sequences of the size cloned in cosmids is 90-95%, and the fluorescent spots produced after FISH are ≈0.3 μm in diameter. Sites of two sequences can be distinguished using two-color FISH. Different reporter molecules, such as biotin or digoxigenin, are incorporated into DNA sequence probes by nick translation. These reporter molecules are labeled after hybridization with different fluorochromes, e.g., FITC and Texas Red. The development of dual band pass filters (Chromatechnology) allows these fluorochromes to be photographed simultaneously without registration shift.


Author(s):  
Gary Bassell ◽  
Robert H. Singer

We have been investigating the spatial distribution of nucleic acids intracellularly using in situ hybridization. The use of non-isotopic nucleotide analogs incorporated into the DNA probe allows the detection of the probe at its site of hybridization within the cell. This approach therefore is compatible with the high resolution available by electron microscopy. Biotinated or digoxigenated probe can be detected by antibodies conjugated to colloidal gold. Because mRNA serves as a template for the probe fragments, the colloidal gold particles are detected as arrays which allow it to be unequivocally distinguished from background.


2007 ◽  
Vol 177 (4S) ◽  
pp. 596-597
Author(s):  
Joseph P. Alukal ◽  
Bobby B. Najari ◽  
Wilson Chuang ◽  
Lata Murthy ◽  
Monica Lopez-Perdomo ◽  
...  

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