Identification and validation by FISH of subtelomeric sequences in long arms of wheat chromosomes 5 and 6
| Autor: | Osuna, Daniel, Calderón, M. Carmen, Aguilar, M. I., Prieto, Pilar |
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| Přispěvatelé: | European Research Council, Ministerio de Economía y Competitividad (España) |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | Trabajo presentado en el XL Congreso de la Sociedad Española de Genética, celebrado en Córdoba del 16 al 18 de septiembre de 2015. Meiosis is a type of cell division that results in the formation of haploid daughter cells. Bread wheat is an hexaploid species (2n = 6x = 42) which has three related genomes (A, B and D). At early meiosis, homologous (identical) chromosomes need to be distinguished from homoeologues (related) to properly associate in pairs. The mechanism by which homologues identify one another is the most poorly understood aspect of meiosis. Recent observations have shown that the subtelomeric region plays a key role in the processes of homologue recognition and subsequent pairing during early meiosis in wheat, but the molecular bases are still unclear. The Wheat Genome Initiative has followed a flow cytometry strategy to separate 10 chromosomes one by one or in groups, the construction of a tiling BAC physical map, and subsequent sequencing of each chromosome using a BAC-by-BAC strategy. The limitations of a shotgun correct assembly and annotations of wheat genome hinder sequencing and assembly of large and repetitive genomes. Currently only a pseudochromosome for wheat chromosome 3B is available. Therefore, the identification and molecular characterization of subtelomeric sequences in wheat chromosome arms is a challenge. Our strategy consisted in considering a specific subtelomeric B-wheat probe contained in BAC clone 205008, which is located in the terminal bin 4BL-10 (0,95-1,0). In order to get a chromosome 4BL contig including the subtelomeric region, we used the application Blastn.sh in a MobaXterm Personal Edition v7.6 terminal screen connected to Picasso supercomputer (Genomics and Bioinformatics Platform of Andalusia, University of Málaga), which provides a basic set of Linux commands. A 5356 nt contig from chromosome 4BL was extracted from 4BL genomic chromosome arm using the BAC clone 205008 subtelomeric fragment. This strategy allowed us to isolate hypothetical subtelomeric contigs from chromosomes 5 and 6 for A, B and D wheat genomes. The validation by FISH of such hypothetical subtelomeric probes is a necessary previous step to unravel the underlying molecular mechanisms involved in the association of each chromosome with 'the right partner' during meiosis. This work has been funded by the EU (ERC Starting Grant 243118) and the National Government (AGL-33264). |
| Databáze: | OpenAIRE |
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