Chromosome elimination in maize induced by supernumerary B chromosomes.

Rhoades, M. M.; Dempsey, Ellen; Ghidoni, A.

doi:10.1073/pnas.57.6.1626

Cited by 44 publications

(22 citation statements)

References 7 publications

(2 reference statements)

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“…Chromosomes containing knobs are especially susceptible to B chromosome-induced instability. Additionally, for chromosomes containing large knobs, addition of two or more B chromosomes causes an increase in breakage and loss at the second pollen mitosis in a specific line of maize (Rhoades et al, 1967;Rhoades and Dempsey, 1972). Thus, in this line, the behavior of knobbed chromosomes with regard to breakage is similar to 9Bic-1 and 7Bic-1 except that the frequency is much lower.…”

Section: Discussionmentioning

confidence: 76%

Centromere Function and Nondisjunction Are Independent Components of the Maize B Chromosome Accumulation Mechanism

Han

Lamb

et al. 2007

The Plant Cell

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Supernumerary or B chromosomes are selfish entities that maintain themselves in populations by accumulation mechanisms. The accumulation mechanism of the B chromosome of maize (Zea mays) involves nondisjunction at the second pollen mitosis, placing two copies of the B chromosome into one of the two sperm. The B chromosome long arm must be present in the same nucleus for the centromere to undergo nondisjunction. A centromere, containing all of the normal DNA elements, translocated from the B chromosome to the short arm of chromosome 9 was recently found to be epigenetically silenced for centromeric function. When intact B chromosomes were added to this genotype, thus supplying the long arm, the inactive centromere regained the property of nondisjunction causing the translocation chromosome 9 to be differentially distributed to the two sperm or resulted in chromosome breaks in 9S, occasionally producing new translocations. Translocation of the inactive B centromere to chromosome 7 transferred the nondisjunction property to this chromosome. The results provide insight into the molecular and evolutionary basis of this B chromosome accumulation mechanism by demonstrating that nondisjunction is caused by a process that does not depend on normal centromere function but that the region of the chromosome required for nondisjunction resides in the centromeric region.

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Section: Discussionmentioning

confidence: 76%

Centromere Function and Nondisjunction Are Independent Components of the Maize B Chromosome Accumulation Mechanism

Han

Lamb

et al. 2007

The Plant Cell

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“…The B chromosomes show instability during meiosis, but present preferential segregation for the nuclei which form gametes, and normal behaviour during the mitotic process, except in the second division of the microspores in the endosperm and tapetal cell, where they show high nondisjunction rates (RANDOLPH, 1941;RHOADES et al, 1967;CARLSON, 1986;GONZÁLEZ-SÁNCHEZ et al, 2004). In the last case, Bs induce instability in the As chromosomes (RHOADES et al, 1967;RHOADES & DEMPSEY, 1972;RHOADES & DEMPSEY, 1973;ALFENITO & BIRCHLER, 1990;CHIAVARINO et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

“…In the last case, Bs induce instability in the As chromosomes (RHOADES et al, 1967;RHOADES & DEMPSEY, 1972;RHOADES & DEMPSEY, 1973;ALFENITO & BIRCHLER, 1990;CHIAVARINO et al, 2000). Such alterations may induce deleterious quantitative phenotypical effects, particularly related to seed fertility reduced, seed germination and flowering time delayed, heading date delayed and seed weight increased (RHOADES et al, 1967;BOUGOURD & JONES, 1997;GONZÁLEZ-SÁNCHEZ et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Meiotic and mitotic behaviour of B chromosomes of ryegrass

Techio

Mittelmann

Marció³

et al. 2009

Cienc. Rural

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“…There is much evidence, from both plants and animals, that B chromosomes can affect many cellular and physiological processes; generally, they have a quantitative effect on characteristics associated with vigour, fertility and fecundity (BOUGOURD 1993). RHOADES et al (1967) discovered an unexpected and dramatic effect resulting from the interac-tion of B chromosomes with the heterochromatic knobs of the A chromosomes, the "high-loss phenomenon". It is characterized by breaks in knobbearing chromosomes and the consequent loss of the acentric portion of the chromosome arm distal to the breakpoint.…”

Section: Introductionmentioning

confidence: 99%