Influence of DNA methylation on rye B-chromosome nondisjunction

Neves, Nuno; Barão, Augusta; Castilho, Alexandra; Silva, M.; Morais, L.; Carvalho, Vitor Oliveira; Viegas, Wanda; Jones, Robert N.

doi:10.1139/g92-098

Cited by 17 publications

(6 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5-Azacytidine has also been reported to alter DNA replication patterns and disturb the cell cycle (34,35). Finally, 5-azacytidine has been reported to cause nondisjunction of B chromosomes in rye (36). The availability of a collection of methylation mutants in a model eukaryote will allow us to examine directly the possible ties between DNA methylation and important functions of the chromosome, including replication, segregation, and gene expression.…”

mentioning

confidence: 99%

Abnormal Chromosome Behavior in Neurospora Mutants Defective in DNA Methylation

Foss

Roberts

Claeys

et al. 1993

Science

125

View full text Add to dashboard Cite

The function and regulation of DNA methylation in eukaryotes remain unclear. Genes affecting methylation were identified in the fungus Neurospora crassa. A mutation in one gene, dim-2, resulted in the loss of all detectable DNA methylation. Abnormal segregation of the methylation defects in crosses led to the discovery that the methylation mutants frequently generate strains with extra chromosomes or chromosomal parts. Starvation for S-adenosylmethionine, the presumed methyl group donor for DNA methylation, also produced aneuploidy. These results suggest that DNA methylation plays a role in the normal control of chromosome behavior.

show abstract

mentioning

confidence: 99%

Abnormal Chromosome Behavior in Neurospora Mutants Defective in DNA Methylation

Foss

Roberts

Claeys

et al. 1993

Science

125

View full text Add to dashboard Cite

show abstract

“…It is known that both in animals and in plants some DNA methylation patterns are modified during meiosis (Holliday 1987, Monk 1987, Neves et al 1992. We suggested that nucleolar dominance in triticale could also be reprogrammed in meiosis through the alteration of rDNA methylation patterns established in somatic cells during early stages of seed development (Castilho et al 1995).…”

Section: Introductionmentioning

confidence: 91%

Reprogramming of rye rDNA in triticale during microsporogenesis

Silva¹,

Queiroz²,

Neves³

et al. 1995

Chromosome Res

Self Cite

View full text Add to dashboard Cite

To test the hypothesis that interspecific genomic and chromosome interactions leading to nucleolar dominance could be reprogrammed in meiosis, we compared the expression of distinct nucleolar organizing region (NOR) loci in hexaploid triticale root tip meristematic cells, pollen mother cells and young pollen grains. Interphase and metaphase cells were silver stained to quantify nucleoli and active NOR loci respectively. A marked difference in the ribosomal RNA gene activity of each locus was observed when different types of cells were compared: in somatic and pollen mother cells, rRNA gene activity was mainly restricted to major wheat NORs (1B and 6B) with only a small contribution from rye NORs (1R). In contrast, in young pollen grains, all NORs present, including the 1R NORs, were consistently active. The expression of all NORs just after meiosis is considered to be a consequence of meiotic reprogramming of rye origin rDNA. Gene reprogramming mediated by the resetting of methylation patterns established early in embryogenesis is suggested to be responsible for the differential expression of the NORs of rye origin in distinct developmental stages of triticale.

show abstract

“…In addition to e¡ects on transcription, non-Mendelian B-chromosome behaviour may also be in£uenced by methylation. Neves et al (1992) showed that induced demethylation (or blocking of methylation) in rye (Secale cerale) causes B chromosomes to undergo mitotic non-disjunction, a known B-chromosome accumulation mechanism.…”

Section: (D) Epigenetic Changes In B Chromosomesmentioning

confidence: 99%

B-chromosome evolution

Camacho

Sharbel

Beukeboom

2000

Phil. Trans. R. Soc. Lond. B

577

631

View full text Add to dashboard Cite

B chromosomes are extra chromosomes to the standard complement that occur in many organisms. They can originate in a number of ways including derivation from autosomes and sex chromosomes in intra- and interspecies crosses. Their subsequent molecular evolution resembles that of univalent sex chromosomes, which involves gene silencing, heterochromatinization and the accumulation of repetitive DNA and transposons. B-chromosome frequencies in populations result from a balance between their transmission rates and their effects on host fitness. Their long-term evolution is considered to be the outcome of selection on the host genome to eliminate B chromosomes or suppress their effects and on the B chromosome's ability to escape through the generation of new variants. Because B chromosomes interact with the standard chromosomes, they can play an important role in genome evolution and may be useful for studying molecular evolutionary processes.

show abstract

Influence of DNA methylation on rye B-chromosome nondisjunction

Cited by 17 publications

References 12 publications

Abnormal Chromosome Behavior in Neurospora Mutants Defective in DNA Methylation

Abnormal Chromosome Behavior in Neurospora Mutants Defective in DNA Methylation

Reprogramming of rye rDNA in triticale during microsporogenesis

B-chromosome evolution

Contact Info

Product

Resources

About