INVESTIGADORES
SEIJO Jose Guillermo
congresos y reuniones científicas
Título:
6. Grabiele, M.; Debat, H. J.; Scaldaferro, M. A.; Seijo, J. G.; Ducasse, D. A.; Moscone, E. A.; Martí, D. A. 2012. 25S-18S ribosomal nature of the not NOR-associated highly GC-rich heterochromatin of chili peppers (Capsicum-Solanaceae)
Autor/es:
GRABIELE MARINAURO; DEBAT H J; SCALDAFERRO, M. A.; SEIJO JG; D. A. DUCASSE; E A. MOSCONE.; MARTÍ, D
Lugar:
Entre Ríos
Reunión:
Congreso; 3er Congreso Argentino de Bioinformática y Biología Computacional. ,; 2012
Institución organizadora:
Sociedad
Resumen:
25S-18S ribosomal nature of the not NOR-associated highly GC-rich heterochromatin of chili peppers (Capsicum-Solanaceae) Autor/es: GRABIELE, M.; DEBAT, H. J.; SCALDAFERRO, M. A.; SEIJO, J. G.; DUCASSE, D. A.; MOSCONE, E. A.; MARTÍ, D. A. Lugar: Oro Verde, Entre Rios Reunión: Congreso; 3er Congreso Argentino de Bioinformática y Biología Computacional; 2012 Institución organizadora: Asociacion Argentina de Bioinformatica y Biologia Computacional Resumen: Background Highly GC-rich heterochromatin (Het) is a universal component of the genome of chili peppers [1]. Fluorescent in situ hybridization (FISH) patterns using Arabidopsis and wheat derived ribosomal (rDNA) probes, embracing rRNA genes and intergenic spacer (IGS) with repetitive blocks segments, revealed a priori co-localization of rDNA and Het regions in Capsicum which promoted a further characterization of the 25S-18S rDNA unit in the genus [2] and the present work. Material and methods To reveal the unambiguous nature of the Het of chili peppers, combined bioinformatics (Database searching, sequence alignments, primary and secondary structures analysis) molecular cytogenetics (FISH) and molecular biology (PCR amplification, restriction enzymes assays, cloning and sequencing) approaches were carried out in 8 taxa representatives of the major lineages of Capsicum. Results A definite FISH co-localization pattern of Capsicum derived rDNA genes (18S, 25S, 5.8S) and spacers (ITS, IGS) probes and Het is exclusive for chili peppers based on x=12. FISH pattern of pCp200/33 probe, a mutated IGS element likely affecting rDNA transcripton, imitate that of rDNA/Het excluding the active NORs. Conclusion Highly GC-rich Het of chili peppers based on x=12 is formed by tandemly repeated mega satellite DNA sequences derived from the 25S-18S rDNA entire unit (7.8 kbp); its origin, expression and evolution are strongly related to its inherent heterochromatic and ribosomal double nature. Its absence in the Het constitution of taxa with x=13 has evolutionary relevance. References 1. Moscone EA, Scaldaferro MA, Grabiele M, Cecchini NM, Sánchez García Y, Jarret R, Daviña JR, Ducasse DA, Barboza GE, Ehrendofer F: The evolution of chili peppers (Capsicum ? Solanaceae): a cytogenetic perspective. Acta Hort 2007, 745:137-169. 2. Grabiele M, Debat HJ, Moscone EA, Ducasse DA: 25S-18S rDNA IGS of Capsicum: molecular structure and comparison. Pl Syst Evol 2012, 298: 313-321.
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