INVESTIGADORES
PESSINO Silvina Claudia
congresos y reuniones científicas
Título:
Molecular mechanisms controlling sequence variation during polyploidization in grass species
Autor/es:
WEIHMULLER E; PODIO M; CORONEL C; ESPINOZA F; SARTOR M; SELVA JP; ECHENIQUE V; SPAMPINATO C; PESSINO S
Lugar:
Rosario
Reunión:
Congreso; XV Congreso Latinoamericano de Genética; 2012
Institución organizadora:
Sociendad Argentina de Genética
Resumen:
In several grass species autopolyploidization was associated with the occurrence of genetic modifications. The objectives of this work were: 1) confirm that the previously reported genetic variation involves specific loci; 2) analyze the role of the DNA repair system in establishing such modifications. Two pairs of P. plicatulum lines with a common genetic background but different ploidies (4C-2x/4C-4x and 7D-2x/7D-4x) were analyzed to detect genetic alterations associated with autopolyploidization. AFLP and RAPD profiles showed 23.98 % and 25.51 % polymorphic loci in the 4C and 7D-derived systems, respectively. Around 20% of these polymorphisms were detected concurrently in both polyploidization events. Prior work had revealed extensive genetic variation (29-32%) following autopolyploidization in Eragrostis curvula. We selected the latter model to quantify the DNA repair system transcript representation in plants with different ploidy and common genetic background. Thirteen genes corresponding to the MMR, BER, NER, nudix helicases, NHEJ, and HR subsystems were studied. None of them showed differential expression associated with polyploidy. Besides, most of the polymorphic fragments isolated from both the Paspalum and Eragrostis systems corresponded to retrotransposons, pseudogenes and retrotransposons+pseudogenes. Our results confirmed the occurrence of conserved genetic alterations during autopolyploidization in the grasses, which do not seem to involve the DNA repair system, but the insertion of retrotransposons into pseudogenes.