Characterization of maize B-chromosome-related transcripts isolated via cDNA-AFLP.
Chromosoma
; 123(6): 597-607, 2014 Dec.
Article
em En
| MEDLINE
| ID: mdl-25082399
ABSTRACT
The maize B-chromosome consists mainly of heterochromatin and is considered to be genetically inert. However, the B-chromosome contains euchromatin that carries control elements that direct its behaviors during cell division, such as nondisjunction during the second pollen mitosis. To determine the transcriptional activity of the B-chromosome, complementary DNA-amplified fragment length polymorphism analysis was applied to five inbred maize lines with and without B-chromosomes. Six putative B-chromosome-related transcripts were identified, four of which were cloned and characterized via Southern hybridization, fluorescence in situ hybridization, and sequence comparison to further confirm their B-chromosome origin. All the analyzed B-chromosome-related transcript sequences were repetitive and showed homology to A-chromosomes. Quantitative real-time reverse transcriptase-polymerase chain reaction revealed that the B-chromosome-specific transcribed sequences B3547-179 and B3849-212 were transcribed in a B-chromosome-dosage-dependent manner. Expression of B3849-189 and B3849-147 was not specific to the B-chromosome; however, the former showed a transcriptional pattern with B-chromosome dosage compensation, and the latter displayed down-regulation of transcription due to higher B-chromosome numbers. Using four B-10L translocations, B3849-212 was mapped to the B-chromosome region that contains the nondisjunction control elements of the B-chromosome. Taken together, our results suggested that the maize B-chromosome harbors few transcriptionally active sequences and might influence the transcription of A-chromosomes.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transcrição Gênica
/
Mecanismo Genético de Compensação de Dose
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Zea mays
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Eucromatina
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Cromossomos de Plantas
Idioma:
En
Revista:
Chromosoma
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Taiwan