Artigo
CYTOGENETIC AND DNA CONTENT IN 6 GENERA OF THE FAMILY CALLICHTHYIDAE (PISCES, SILURIFORMES)
Fecha
1993-04-01Registro en:
Caryologia. Florence: Univ Florence Botany Inst, v. 46, n. 2-3, p. 171-188, 1993.
0008-7114
WOS:A1993MH88400009
Autor
Universidade de São Paulo (USP)
Universidade Estadual Paulista (Unesp)
Resumen
Cytogenetic studies involving conventional Giemsa staining, C-banding analysis and silver staining of NORs were performed on nine species belonging to six genera of the family Callichthyidae. The diploid number ranged from 2n = 44 to 2n = 100, the number of chromosomal pairs with NORs ranged from 1 to 4 and constitutive heterochromatin was mainly distributed in the centromeric and/or pericentromeric position of the chromosomes. The DNA content of erythrocytes from six species studied ranged from 1.18 +/- 0.07 to 2.77 +/- 0.22 pg/nucleus. The extensive variability in karyotypes and in nuclear DNA content detected are in accordance with the initial hypothesis that chromosome rearrangements and polyploidy have played a significant role in the evolutionary history of Callichthyidae.