Movement ability of rye terminal neocentromeres
Author(s)
Puertas, M.
Garcia-Chico, R.
Sotillo, E.
Gonzalez-Sanchez, M.
Manzanero, S.
Griffith University Author(s)
Year published
2005
Metadata
Show full item recordAbstract
Rye terminal neocentromeres were analyzed in various aspects. Plants with and without neocentromeres were crossed to determine the possible genetic control on their formation. The segregation obtained in our work is consistent with the hypothesis of two trans-acting genes determining neocentric activity in such a way that individuals with no neocentromeres at all would carry all non-activating alleles, whereas one activating allele might permit the activation of a few neocentromeres. Individuals with four activating alleles would show the maximum frequency of neocentromeres per cell. Anti-tubulin immunolabelling was used to ...
View more >Rye terminal neocentromeres were analyzed in various aspects. Plants with and without neocentromeres were crossed to determine the possible genetic control on their formation. The segregation obtained in our work is consistent with the hypothesis of two trans-acting genes determining neocentric activity in such a way that individuals with no neocentromeres at all would carry all non-activating alleles, whereas one activating allele might permit the activation of a few neocentromeres. Individuals with four activating alleles would show the maximum frequency of neocentromeres per cell. Anti-tubulin immunolabelling was used to visualize the interaction between the neocentromeres and the microtubules. In most cases an end-on interaction between neocentromeres and microtubules was observed, but a few neocentromeres were observed free of them. Spikes were irradiated at early meiosis to determine whether acentric fragments carrying subtelomeric heterochromatin were able to behave as neocentromeres. In no case were acentric fragments observed to form an extension polewards as they did in whole chromosomes. Broken chromosomes joined by a thin thread of chromatin to the centromeric region showed neocentric activity, strongly suggesting that subtelomeric sequences need a cis-acting centromere to be active as neocentromeres.
View less >
View more >Rye terminal neocentromeres were analyzed in various aspects. Plants with and without neocentromeres were crossed to determine the possible genetic control on their formation. The segregation obtained in our work is consistent with the hypothesis of two trans-acting genes determining neocentric activity in such a way that individuals with no neocentromeres at all would carry all non-activating alleles, whereas one activating allele might permit the activation of a few neocentromeres. Individuals with four activating alleles would show the maximum frequency of neocentromeres per cell. Anti-tubulin immunolabelling was used to visualize the interaction between the neocentromeres and the microtubules. In most cases an end-on interaction between neocentromeres and microtubules was observed, but a few neocentromeres were observed free of them. Spikes were irradiated at early meiosis to determine whether acentric fragments carrying subtelomeric heterochromatin were able to behave as neocentromeres. In no case were acentric fragments observed to form an extension polewards as they did in whole chromosomes. Broken chromosomes joined by a thin thread of chromatin to the centromeric region showed neocentric activity, strongly suggesting that subtelomeric sequences need a cis-acting centromere to be active as neocentromeres.
View less >
Journal Title
Cytogenetic and Genome Research
Volume
109
Issue
1-3
Subject
Genetics