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. 1998 Oct 27;95(22):13073-8.
doi: 10.1073/pnas.95.22.13073.

Chromosome-specific molecular organization of maize (Zea mays L.) centromeric regions

E V Ananiev  1 , R L Phillips, H W Rines
Affiliations

Chromosome-specific molecular organization of maize (Zea mays L.) centromeric regions

E V Ananiev et al. Proc Natl Acad Sci U S A. .

Abstract

A set of oat-maize chromosome addition lines with individual maize (Zea mays L.) chromosomes present in plants with a complete oat (Avena sativa L.) chromosome complement provides a unique opportunity to analyze the organization of centromeric regions of each maize chromosome. A DNA sequence, MCS1a, described previously as a maize centromere-associated sequence, was used as a probe to isolate cosmid clones from a genomic library made of DNA purified from a maize chromosome 9 addition line. Analysis of six cosmid clones containing centromeric DNA segments revealed a complex organization. The MCS1a sequence was found to comprise a portion of the long terminal repeats of a retrotransposon-like repeated element, termed CentA. Two of the six cosmid clones contained regions composed of a newly identified family of tandem repeats, termed CentC. Copies of CentA and tandem arrays of CentC are interspersed with other repetitive elements, including the previously identified maize retroelements Huck and Prem2. Fluorescence in situ hybridization revealed that CentC and CentA elements are limited to the centromeric region of each maize chromosome. The retroelements Huck and Prem2 are dispersed along all maize chromosomes, although Huck elements are present in an increased concentration around centromeric regions. Significant variation in the size of the blocks of CentC and in the copy number of CentA elements, as well as restriction fragment length variations were detected within the centromeric region of each maize chromosome studied. The different proportions and arrangements of these elements and likely others provide each centromeric region with a unique overall structure.

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Figures

Figure 1
Figure 1
Composition of cloned centromeric DNA segments from maize chromosome 9. (A) Six cosmid clones (3, 6, 16, 27, 29, and 31) containing centromeric DNA sequence MCS1a have different restriction profiles after digestion with XmnI restriction enzyme. (B) Hybridization with labeled genomic DNA indicates that almost all the subfragments contain medium or highly repetitive DNA sequences, some of which were identified as Huck and Prem2 retrotransposable elements. (C) Hybridization with the labeled CentC element shows that this repeated element is present in two cosmid clones, 3 and 29. Monomeric or dimeric units of this element are seen as a 156–312 bp group of fragments. (D) Hybridization with the labeled CentA element shows that it is present in all six cosmid clones, but in fragments of different lengths.
Figure 2
Figure 2
Molecular maps of the centromeric DNA segments cloned in cosmids 3 and 29 isolated from maize chromosome 9. The XmnI restriction sites are indicated by vertical lines within the bars. Positions for the Sau3A restriction sites are indicated by solid vertical arrows for the CentC tandem arrays only. The left vertically hatched parts of the cloned segments are composed of arrays of the CentC elements about 10 kb in length in cosmid 29 and 23 kb in length in cosmid 3. Some segments of the right portions of cosmids 3 and 29 were sequenced. Stippled bars represent sequenced segments of cosmid 3, and the upper, heavily shaded bars represent sequenced segments of cosmid 29 as they correspond to cosmid 3 sequences. A new retrotransposon-like element, CentA, was identified between nucleotides 1309 and 5944 of the large sequenced segment of cosmid 3; this element contains two LTRs, 1,304 and 1,305 bp in length, respectively (indicated by arrows). To the left of this element, ORF1 was identified. The right end of cosmid 3 contains a portion of the Prem2 retrotransposable (10) element that corresponds to the section of the published DNA sequence of this element included between nucleotides 3357 and 9416.
Figure 3
Figure 3
FISH of maize metaphase chromosomes with fluorescein-labeled CentA element (A) (the 3.3-kb XmnI fragment on Fig. 2) and rhodamine-labeled CentC element (B). Both probes hybridize with centromeric regions. There is variation among different chromosomes in the intensity of hybridization signals (C–E). FISH of maize prophase chromosomes (C) (4′,6-diamino-2-phenylindole-counterstained after in situ hybridization) with rhodamine-labeled CentC element (D) and fluorescein-labeled Huck element (E). The Huck element is dispersed along all maize chromosomes with an increased concentration around centromeric regions.
Figure 4
Figure 4
Polymorphic organization of centromeric sequences of maize chromosomes. Southern blot hybridization of labeled CentA (B) and CentC (C) probes to a panel of chromosome addition lines of maize. (A) Ethidium bromide stained gel of EcoRI digested DNA samples from maize, oat, and six chromosome addition lines with maize chromosomes 2, 3, 4, 7, 8, and 9, respectively. The CentA element hybridizes to 10–20 polymorphic fragments in each maize chromosome. There is a faint hybridization with oat genomic DNA. The CentC element mostly hybridizes to high molecular weight DNA in each chromosome. Increased copy numbers exist in chromosomes 7, 8, and 9.
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References

    1. Rines H W, Riera-Lizarazu O, Phillips R L. In: Modification of Gene Expression and Non-Mendelian Inheritance. Oono K, Takiwa F, editors. Tsukuba, Japan: NIAR; 1995. pp. 235–251.
    1. Riera-Lizarazu O, Rines H W, Phillips R L. Theor Appl Genet. 1996;93:123–135. - PubMed
    1. Cox D R, Burmeister M, Price E R, Kim S, Myers R M. Science. 1990;250:245–250. - PubMed
    1. Olson M V. Proc Natl Acad Sci USA. 1993;90:4338–4344. - PMC - PubMed
    1. Ananiev E V, Riera-Lizarazu O, Rines H W, Phillips R L. Proc Natl Acad Sci USA. 1997;94:3524–3529. - PMC - PubMed

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