Karyotype, C- and fluorescence banding patterns, NOR location and FISH in the grasshopperXestotrachelus robustus(Romaleidae)

Chromosome study in Schistocerca (Orthoptera-Acrididae-Cyrtacanthacridinae): karyotypes and distribution patterns of constitutive heterochromatin and nucleolus organizer regions (NORs)

“…In grasshoppers, chromosome localization of rDNA genes by FISH has been performed in Acrididae (López-León et al, 1999;Santos et al, 1990;Vaughn et al, 1999) and Romaleidae (Souza et al, 1998;Souza et al, 2003). Variation in the distribution of rDNA sites and/or Ag-NORs, as we observed in S. flavofasciata and S. pallens, have been found in many insect species pointing to the importance of these patterns as phylogenetic markers in the genus Schistocerca.…”

“…In the acridoids Chorthippus brunneus and C. jacobsi, the pericentromeric regions of all chromosomes showed CMA 3 -positive CH blocks (Bridle et al, 2002). The romaleids Xyleus angulatus, Phaeoparia megacephala and Xestotrachelus robustus (Souza et al, 1998;Pereira and Souza, 2000;Souza et al, 2003) also presented CMA 3 -positive CH blocks on all chromosomes. Differences in size and distribution of CH blocks have been described in several grasshopper species.…”

“…C-banding and Ag-NOR staining have been of great importance for inter and intra-specific characterization and karyotypic differentiation in grasshoppers (Santos el al., 1983, Cabrero and Camacho 1986a, 1986bSouza and Kido, 1995;Pereira and Souza, 2000;Rocha et al, 2004). Fluorochrome staining and fluorescent in situ hybridization (FISH) have also been used to, respectively, map AT-and GC-rich chromosome regions and locate ribosomal genes (López-León et al, 1999;Santos et al, 1990;Souza et al, 1998;Pereira and Souza 2000;Souza et al, 2003).…”

A Comparative Cytogenetic Analysis between the Grasshopper Species Chromacris nuptialis and C. speciosa (Romaleidae): Constitutive Heterochromatin Variability and rDNA Sites

“…Bar = 10 lm. Melo, 2003). Indeed, romaleid species have shown a highly conserved karyotype, with only a few cases of rearrangements being known (X-autosome and autosome-autosome fusion), what lead to a reduction in chromosome number (Mesa, Ferreira & Carbonell, 1982).…”

“…Nevertheless, analysis of constitutive heterochromatin (CH) by C-banding has revealed both variations in terms of the quantity and location of CH blocks, among different species. Pericentromeric location has been the most frequent having been observed in seven out of eight species studied so far (Vilardi, 1986;Souza & Kido, 1995;Pereira & Souza, 2000;Souza, Haver & Melo, 2003). Additionaly, ocurrence of interstitial and distal blocks has been reported for Xyleus angulatus (Souza & Kido, 1995;Souza, Rufas & Orellana, 1998), Radacridium mariajoseae, R. nordestinum (Rocha, Souza & Tashiro, 1997), and Chromacris speciosa (Souza & Kido, 1995).…”