INVESTIGADORES
PESSINO Silvina Claudia
congresos y reuniones científicas
Título:
Characterization of retroelements differentially expressed in inflorescences of apomictic and sexual Paspalum notatum plants
Autor/es:
OCHOGAVÍA A; SEIJO G; GONZÁLEZ AM; PODIO M; ORTIZ JPA; PESSINO SC
Lugar:
La Plata
Reunión:
Congreso; XXVIII Reunión Argentina de Fisiología Vegetal; 2010
Institución organizadora:
Sociedad Argentina de Fisiología Vegetal
Resumen:
Apomixis is an asexual mode of reproduction through seeds. The aim of this work was to characterize two unknown RNA fragments (N17 and N22) differentially expressed in inflorescences of apomictic and sexual Paspalum notatum plants, which had been identified in previous experiments. RACE-extended N17 sequence showed similarity to a centromeric retrotransposon and included a protein-coding gene fragment. Genetic mapping revealed location onto the linkage group M8 centromeric region. N22 RACE experiments allowed the isolation of a group of related transcripts homologous to gypsy retroelements, which included short segments of genes that had been associated with apomixis in previous reports (serk, cytP450). Chronological real-time PCR analysis showed a highly significant differential activation in apomicts at the meiotic stage. Surprisingly, reproductive tissue in situ hybridization experiments revealed a higher representation of N17 and N22 related sequences in ovules of the sexual genotype. We hypothesized that N17 and N22 belonged to retrotransposon families with specific members expressed in apomictic and sexual plant types. A retrotransposon-specific differential display analysis was conducted to identify several members of N22 retrotransposon family, which were preferentially represented in the sexual genotype. Our results indicate that N17 and N22 are retrotransposon sequences carrying protein-coding gene segments and belong to complex families of retroelements with differential expression in apomictic and sexual plants. The presence of segments of genes previously associated with apomictic development within the retrotransposon sequences strongly suggest that these elements could be participating in regulatory pathways related with apomixis and sexuality.