Microsatellite megatracts in the maize (Zea mays L.) genome

Long tracts (megatracts) of (CAG)n, (TAG)n, and (GAA)n microsatellite sequences capable of forming composite DNA segments were found in the maize (Zea mays L.) genome. Some of the (CAG)n and (TAG)n megatracts were organized in clusters of up to 1 Mb on several chromosomes, as detected by fluorescence in situ hybridization (FISH), as well as on extended DNA fibers. Extensive polymorphism was found among different maize inbred lines with respect to the number and size of microsatellite megatract clusters on the A chromosomes. Polymorphism was also common among B chromosomes of different nuclei in the inbred line Zapalote Chico. Different retrotransposable elements were often inserted into the microsatellite tracts. Size variation in some (TAG)n and (GAA)n megatracts was observed in consecutive generations among siblings of the inbred lines, indicating that these loci are highly unstable and predisposed to dynamic mutations similar to those described in mammalian systems.Key words: maize, microsatellites, SSR, markers, FISH.

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Physical localization of single-copy sequences on pachytene chromosomes in maize (Zea mays L.) by chromosome in situ suppression hybridization

Genome ◽

10.1139/g00-085 ◽

2000 ◽

Vol 43 (6) ◽

pp. 1081-1083 ◽

Cited By ~ 13

Author(s):

Monther T Sadder ◽

Norbert Ponelies ◽

Ute Born ◽

Gerd Weber

Keyword(s):

Zea Mays ◽

In Situ Hybridization ◽

Fluorescence In Situ Hybridization ◽

Dna Sequence ◽

Zea Mays L ◽

Single Copy ◽

Chromosome 9 ◽

Copy Dna ◽

Single Copy Dna

A new approach for locating single-copy DNA sequences on pachytene chromosomes of maize (Zea mays L.) was developed. A cosmid clone with homologous sequences to a molecular marker (umc105a) linked to a quantitative trait locus (QTL) for resistance against sugarcane borer (SCB) was physically mapped by fluorescence in situ hybridization (FISH) to the short arm of chromosome 9. The marker umc105a was genetically placed in the centromeric region. To suppress signals generated by maize repetitive DNA, competitive in situ suppression (CISS) hybridization was necessary to obtain specific signals from umc105a. A centromere specific DNA probe (CentC) was used in a double-labeling technique as a reference marker. Fluorescence signals generated by umc105a cosmid and CentC were specific and highly reproducible. Thus the single-copy DNA sequence of umc105a was physically localized on the short arm of chromosome 9 near the telomere. This is the first report of physical localization of single-copy DNA sequence by CISS hybridization to a maize pachytene chromosome.Key words: fluorescence in situ hybridization, maize, pachytene chromosome, single-copy sequence, CISS hybridization.

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Fluorescence In Situ Hybridization to Maize (Zea mays) Chromosomes

Current Protocols in Plant Biology ◽

10.1002/cppb.20033 ◽

2016 ◽

Vol 1 (3) ◽

pp. 530-545 ◽

Cited By ~ 2

Author(s):

Morgan McCaw ◽

Nathaniel Graham ◽

Jon Cody ◽

Nathan Swyers ◽

Changzeng Zhao ◽

...

Keyword(s):

Zea Mays ◽

In Situ Hybridization ◽

Fluorescence In Situ Hybridization

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RAPD markers encoding retrotransposable elements are linked to the male sex in Cannabis sativa L.

Genome ◽

10.1139/g05-056 ◽

2005 ◽

Vol 48 (5) ◽

pp. 931-936 ◽

Cited By ~ 37

Author(s):

Koichi Sakamoto ◽

Tomoko Abe ◽

Tomoki Matsuyama ◽

Shigeo Yoshida ◽

Nobuko Ohmido ◽

...

Keyword(s):

In Situ Hybridization ◽

Fluorescence In Situ Hybridization ◽

Y Chromosome ◽

Dna Sequences ◽

Blot Analysis ◽

Cannabis Sativa ◽

Random Amplified Polymorphic Dna ◽

Male And Female ◽

Retrotransposable Elements

Male-associated DNA sequences were analyzed in Cannabis sativa L. (hemp), a dioecious plant with heteromorphic sex chromosomes. DNA was isolated from male and female plants and subjected to random amplified polymorphic DNA analysis. Of 120 primers, 17 yielded 400 to 1500-bp fragments detectable in male, but not female, plants. These fragments were cloned and used as probes in gel-blot analysis of genomic DNA. When male and female DNA was hybridized with 2 of these male-specific fragments, MADC(male-associated DNA sequences in C. sativa)3 and MADC4, particularly intense bands specific to male plants were detected in addition to bands common to both sexes. The MADC3 and MADC4 sequences were shown to encode gag/pol polyproteins of copia-like retrotransposons. Fluorescence in situ hybridization with MADC3 and MADC4 as probes revealed a number of intense signals on the Y chromosome as well as dispersed signals on all chromosomes. The gel-blot analysis and fluorescence in situ hybridization results presented here support the hypothesis that accumulation of retrotransposable elements on the Y chromosome might be 1 cause of heteromorphism of sex chromosomes.Key words: Cannabis sativa, FISH, RAPD, retrotransposon, sex chromosome.

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