Karyotype, C-and fluorescence banding pattern, NOR location and FISH study of five Scarabaeidae (Coleoptera) species

Edgar Bione,Reginaldo De Carvalho,Rita De Cássia De Moura,Maria José De Souza

doi:10.1590/s1415-47572005000300006

Edgar Bione, Reginaldo De Carvalho + Show 2 more

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https://doi.org/10.1590/s1415-47572005000300006

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Abstract

Meiotic chromosomes obtained from members of the coleopteran subfamilies Rutelinae and Dynastinae were studied using standard and silver nitrate staining, C-banding, base-specific fluorochromes and fluorescent in situ hybridization (FISH). The study presents detailed karyotipic descripitions of three Rutelinae species (Geniates borelli, Macraspis festiva and Pelidnota pallidipennis), and two Dynastinae species (Lygirus ebenus and Strategus surinamensis hirtus) with special emphasis on the distribution and variability of constitutive heterochromatin and the nucleolar organizer region (NOR). We found that for G. borelli, P. pallidipennis, L. ebenus and S. s hirtus the karyotype was 2n = 20 (9II + Xy p), with G. borelli, P. pallidipennis and L. ebenus showed meta-submetacentric chromosomes which gradually decreased in size. For Macraspis festiva the karyotype was 2n = 18 (8II + Xy p). In L. ebenus we found that the NOR was located on an autosome, but in the other four species it occurred on the sex bivalents. In all five species the constitutive heterochromatin (CH) was predominantly pericentromeric while the X chromosomes were almost completely heterochomatic, although CMA3/DA/DAPI staining showed intra and interspecific variation in the bright fluorescence of the constitutive heterochromatin. The FISH technique showed rDNA sites on the X chromosome of the Rutelinae species.

Highlights

The coleopteran family Scarabaeidae is made up of a cosmopolitan group of approximately 2,300 genera and 27,000 species worldwide distributed with a highly conserved diploid chromosome number (2n = 20) and Xy typeparachute’ (Xyp) sex-determining mechanism, there is variation in chromosome morphology (Smith and Virkki, 1978; Yadav and Pillai, 1979; Colomba et al, 1996)
Data regarding the localization of the nucleolar organizer regions (NORs) in the scarab Phyllophaga (Phytalus) vestita and Lyogenys fuscus obtained by silver nitrate staining and fluorescence in situ hybridization (FISH) have shown that the ribosomal sites are preferentially located on the sex chromosomes (Moura et al, 2003), in Gymnopleurus sturmi and Phyllophaga (P.) aff capillata (Scarabaeidae), Trotectes intermedius (Geotrupidae), Eriopis connexa (Coccinellidae) and in 19 Zabrus species (Carabidae), the NORs are located on the autosomes (Vitturi et al, 1999; Colomba et al, 2000; Maffei et al, 2000; Sánchez-Géa et al, 2000; Moura et al, 2003)
We found that G. borelli, P. pallidipennis, L. ebenus and S. s. hirtus had the 2n = 20 (9II + Xyp) karyotype typical of the suborder Polyphaga, but M. festiva karyotype of 2n = 18 (8II+ Xyp) which coincided with the karyotype of Macraspis dichroa (Vidal, 1984)

Summary

Introduction

The coleopteran family Scarabaeidae is made up of a cosmopolitan group of approximately 2,300 genera and 27,000 species worldwide distributed with a highly conserved diploid chromosome number (2n = 20) and Xy typeparachute’ (Xyp) sex-determining mechanism, there is variation in chromosome morphology (Smith and Virkki, 1978; Yadav and Pillai, 1979; Colomba et al, 1996). Differential techniques have rarely been applied to chromosome studies of the Coleoptera, but data from the species so far analyzed have shown that the autosomal constitutive heterochromatin (CH) is preferentially located on pericentromeric region and is less frequent on interstitial and telomeric regions while the position of sex chomosome constitutive heterochromatin is more variable in that it may be pericentromeric or entirely heterochromatic (Vidal et al, 1977; Angus, 1983; Drets et al, 1983; Virkki, 1983; Juan and Petitpierre, 1989; Rozek and Lachowska, 2001). Data regarding the localization of the nucleolar organizer regions (NORs) in the scarab Phyllophaga (Phytalus) vestita and Lyogenys fuscus obtained by silver nitrate staining and fluorescence in situ hybridization (FISH) have shown that the ribosomal sites are preferentially located on the sex chromosomes (Moura et al, 2003), in Gymnopleurus sturmi and Phyllophaga (P.) aff capillata (Scarabaeidae), Trotectes intermedius (Geotrupidae), Eriopis connexa (Coccinellidae) and in 19 Zabrus species (Carabidae), the NORs are located on the autosomes (Vitturi et al, 1999; Colomba et al, 2000; Maffei et al, 2000; Sánchez-Géa et al, 2000; Moura et al, 2003).

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