Artículo
Highly GC-rich heterochromatin in chili peppers (Capsicum-Solanaceae): A cytogenetic and molecular characterization
Grabiele, Mauro
; Debat, Humberto Julio
; Scaldaferro, Marisel Analía
; Aguilera, Patricia Mabel
; Moscone, Eduardo Alberto
; Seijo, José Guillermo
; Ducasse, Daniel Adrián






Fecha de publicación:
08/2018
Editorial:
Elsevier Science
Revista:
Scientia Horticulturae
ISSN:
0304-4238
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Resumen
Capsicum comprises 35 species of chili peppers and five of them are cultivated worldwide as spices or vegetables. Diploid karyotypes based in x = 12 and x = 13 are common in Capsicum and the constitutive heterochromatin (cHet) is of particular interest in the genus since it is largely variable, particularly its highly GC-rich fraction. However, the repetitive DNA components of this heterochromatic regions are unknown. Given the co-localization of rDNA loci with the CMA+DAPI– heterochromatic bands, we tested the hypothesis that the highly GC-rich cHet fraction is composed of the whole 18S-25S ribosomal DNA (rDNA) unit or some of its components. Here we report on a novel satellite for Capsicum and Solanaceae composed of the complete rDNA unit. We physically mapped six Capsicum derived specific 18S-25S rDNA probes that covered the entire span of the rDNA unit and analysed a DraI restriction product on eight chromosomally different taxa of Capsicum, representative of the major phylogenetic clades of chili peppers. The co-localization of every gene and spacer probes of the 18S-25S rDNA unit suggest their structural function as a major repetitive component of the highly GC-rich cHet in Capsicum species with x = 12. In addition, analyses of the clones derived from restriction assays in C. pubescens suggested that the differential functional status of 18S-25S rDNA loci (nucleolar organizer regions -NORs- or cHet) in this species is related to a divergence in a short sequence upstream the regulatory transcription initiation site (TIS) of the intergenic spacer (IGS). The results here provided evidence that an rDNA mega satellite played a significant role in the evolution of the karyotype features of x = 12 Capsicum species. The finding of a mega satellite family derived from the whole rDNA unit is a novelty for plant genomes.
Archivos asociados
http://dx.doi.org/10.1016/j.scienta.2018.04.060
https://www.sciencedirect.com/science/article/pii/S0304423818303157
https://www.sciencedirect.com/science/article/pii/S0304423818303157

Citación:
Grabiele, Mauro; Debat, Humberto Julio; Scaldaferro, Marisel Analía; Aguilera, Patricia Mabel; Moscone, Eduardo Alberto; et al.; Highly GC-rich heterochromatin in chili peppers (Capsicum-Solanaceae): A cytogenetic and molecular characterization; Elsevier Science; Scientia Horticulturae; 238; 8-2018; 391-399
Comunidades y colecciones
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Articulos(IMBIV) [1462]
Articulos de INST.MULTIDISCIPL.DE BIOLOGIA VEGETAL (P) -
Articulos(IBS) [197]
Articulos de INSTITUTO DE BIOLOGIA SUBTROPICAL -
Articulos(IBONE) [650]
Articulos de INST.DE BOTANICA DEL NORDESTE (I)