Molecular cytogenetic physical mapping of Sorghum bicolor chromosomes /
S. bicolor (Moench.) BAC clones were selected from the TAMU
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1997.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=736824351&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | S. bicolor (Moench.) BAC clones were selected from the TAMU sorghum BAC library after screening with twenty three PUC18 clones previously used to construct a sorghum RFLP map and two cDNA clones, one containing the sorghum alcohol dehydrogenase (adh) gene, and the other the maize shrunken-2 (sh2) gene. The BACs were used for fluorescent in situ hybridization (FISH) to chromosome spreads from root tips of disomic and trisomic S. bicolor plants. BAC 86 B6 (205 Kb) and 51 H9 (200 Kb) containing sequences complementary to maize sh-2 and sorghum adh cDNAs, were localized by FISH to trisomic chromosome Dt and chromosome A, respectively. FISH of the selected BAC clones collectively marked 19 single-copy sites on seven different chromosomes. One marked chromosome Dt (86 B6); 2 marked chromosome It (129 E8 and 122 D4); 2 marked chromosome Ht (128 H10 and 135 D6); 3 marked the short arm of chromosome A (110 G5, 146 D5, and 116 B9); 4 marked the long arm of chromosome A (24 B2, 24 B5, 125 H5, and 51 H9); and one marked each of three different but unidentified chromosomes (126 H5, 114 H5, and 16 B12). Dualcolor FISH was used to order four different BACs on chromosome A (24 B2, 125 H5, 110 G5, and 146 D5), and two different BACs on chromosome Ht (128 H10 and 135 D6). BACs 22 B2 (45 Kb) and 128 H4 preferentially hybridized to centromeric regions. Moreover, hybridization was much stronger on 5 of the 10 pairs of S. bicolor chromosomes, providing extremely strong evidence that S. bicolor is tetraploid, with five chromosomes per set. Each set of five chromosomes can be termed a subgenome. Both, molecular recombinational mapping and physical mapping utilizing FISH of RFLP-selected BACs suggest that extensive rearrangement has occurred among the sorghum chromosomes following polyploidization. |
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| Item Description: | Vita. "Major Subject: Genetics". |
| Physical Description: | xiii, 70 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 62-69. |