title: Development and mapping of CL-repeat display markers on the maize B chromosome.
abstract: The CL-repeat is a repetitive sequence that is unique to the maize B chromosome, where it resides in the centromeric knob and the first 3 distal heterochromatic regions of the long arm. Given this organization, it would be desirable to identify molecular markers that are specifically distributed in the B chromosome. In this report, the CL-repeat has been used to develop a class of molecular markers for the maize B chromosome. To this end, a modified transposon display procedure designated as CL-repeat display was used to generate and display 26 genomic fragments that are specific to the B chromosome, all of which were cloned and sequenced. The sequences of 19 fragments were highly homologous to the 5' or 3' terminus of the CL-repeat. Five of these fragments also contained sequences that were homologous to sequences of the B chromosome centromere. Four of the other 7 fragments shared homology with B chromosome centromere sequences, and the remaining 3 were of unidentified sequences. Using 13 B-10L translocations with various breakpoints along the B chromosome long arm, the 26 CL-repeat display markers were mapped to definite regions of the B chromosome. This strategy should be feasible for the development of molecular markers for the B chromosome in maize and in other species where B chromosome-specific repeats have been identified.
authors.affiliation: Department of Agronomy, National Chung Hsing University, Taichung, Taiwan, ROC.
authors.forename: Yu-Lun
authors.initials: YL
authors.lastname: Chien
authors.forename: Chien-Yu
authors.initials: CY
authors.lastname: Lin
authors.forename: Kuan-Lin
authors.initials: KL
authors.lastname: Lo
authors.forename: Ya-Ming
authors.initials: YM
authors.lastname: Cheng
mesh_terms: D032461:Chromosomes, Plant / Q000235:genetics*; D005819:Genetic Markers; D006801:Humans; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D003313:Zea mays / Q000235:genetics*
chemical_list: D005819:Genetic Markers