INVESTIGADORES
FERRUCCI Maria silvia
artículos
Título:
Differences and resemblances in banding patterns and ribosomal DNA distribution in four species of Paullinieae tribe (Sapindaceae)
Autor/es:
URDAMPILLETA J.D., FERRUCCI M.S., VANZELA A.L.L. & FORNI MARTINS E.R.
Revista:
CYTOLOGIA
Editorial:
The Japon Mendel Society, International Society of Cytology
Referencias:
Lugar: Tokyo; Año: 2008 vol. 73 p. 283 - 291
ISSN:
0011-4545
Resumen:
The tribe Paullinieae (Sapindaceae) is exclusively neotropicallydistributed, and is characterized by apomorphic characters and considered amonophyletic natural group. Recently explored cytogenetical aspects suggestthat the disploid chromosomal reduction, the increase in the chromosomal sizeand the diversification of highly repetitive DNA sequences are associated withthe karyotypic evolution of this tribe. This work compares patterns ofchromosome banding and the distribution of ribosomal DNA 18S-5.8S-26S in Cardiospermumgrandiflorum Sw., Pullinia elegans Cambess., Urvillea chacoensis Hunz.and U. ulmacea Kunth. The studied species share the presence of apattern of terminal C-Giemsa bands, differentiated for characteristics ofheterochromatic regions. Terminal AT-rich bands occurred in C. grandiflorum (2n_2x_20)and U. chacoensis (2n_2x_22). Differing from the others, U.chacoensis presented prominent bands in the majority of chromosomes. Thepolyploid cytotype of U. ulmacea (2n_8x_88) possessedterminal bands CMA_ and DAPI_, forming heterochromatic blocks constituted byGC- and AT-rich repetitive DNA. On the other hand, P. elegans (2n_2x_24)presented a pattern of neutral bands after staining with CMA3/DAPI. Thepresence of GC-rich regions associated with 45S rDNA sites was a commoncharacteristic in the studied species, nevertheless, variations in the NORnumber might be useful for the differentiation of some species. Our results onkaryological differences and resemblances of the studied species are discussedin relation to the systematics of the Paullinieae tribe.