Molecular characterization of a maize B chromosome centric sequence

• Published in: Genetics (Austin) Vol. 135; no. 2; pp. 589 - 597
• Main Authors: Alfenito, M.R, Birchler, J.A
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Genetics Soc America 01-10-1993; Genetics Society of America
• Subjects: ADN; Base Sequence; Biological and medical sciences; Blotting, Southern; Centromere - ultrastructure; Chromatin. Chromosome; CHROMOSOME; Chromosome Mapping; Chromosomes - ultrastructure; Corn; CROMOSOMAS; DNA - isolation & purification; DNA Probes; Fundamental and applied biological sciences. Psychology; Genes; GENETICA; Genetics; GENETIQUE; Investigations; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Restriction Mapping; SECUENCIA NUCLEICA; SEQUENCE NUCLEIQUE; ZEA MAYS; Zea mays - genetics; Genetic mapping; Molecular hybridization; Monocotyledones; Zea mays; Nucleotide sequence; In situ; Accessory B chromosome; Homology; Centromere; Gramineae; Angiospermae; Chromosome DNA; Spermatophyta
• ISSN: 0016-6731; 1943-2631; 1943-2631
• DOI: 10.1093/genetics/135.2.589

Supernumerary chromosomes are widespread in the plant kingdom but little is known of their molecular nature or mechanism of origin. We report here the initial cloning of sequences from the maize B chromosome. Our analysis suggests that many sequences are highly repetitive and shared with the normal A chromosomes. However, all clones selected for B-specificity contain at least one copy of a particular repeat. Cytological mapping using B chromosome derivatives and in situ hybridization show that the B specific repeats are derived from the centric region of the chromosome. Sequence analysis of this repeat shows homology to motifs mapped to various plant and animal centromeres and to the maize neocentromere. A precise localization of these sequences among breakpoints within the B centromere and an homology to a facultative centromere, suggest a role for this sequence in centromere function