title: Evolutionary chromosomal differentiation among four species of Conoderus Eschscholtz, 1829 (Coleoptera, Elateridae, Agrypninae, Conoderini) detected by standard staining, C-banding, silver nitrate impregnation, and CMA3/DA/DAPI staining.
abstract: The speciose Brazilian Elateridae fauna is characterized by high karyotypic diversity, including one species (Chalcolepidius zonatus Eschscholtz, 1829) with the lowest diploid number within any Coleoptera order. Cytogenetic analysis of Conoderus dimidiatus Germar, 1839, C. scalaris (Germar, 1824,) C. ternarius Germar, 1839, and C. stigmosus Germar, 1839 by standard and differential staining was performed with the aim of establishing mechanisms of karyotypic differentiation in these species. Conoderus dimidiatus, C. scalaris, and C. ternarius have diploid numbers of 2n(male) = 17 and 2n(female) = 18, and a X0/XX sex determination system, similar to that encountered in the majority of Conoderini species. The karyotype of C. stigmosus was characterized by a diploid number of 2n = 16 and a neoXY/neoXX sex determination system that was highly differentiated from other species of the genus. Some features of the mitotic and meiotic chromosomes suggest an autosome/ancestral X chromosome fusion as the cause of the neoXY system origin in C. stigmosus. C-banding and silver impregnation techniques showed that the four Conoderus species possess similar chromosomal characteristics to those registered in most Polyphaga species, including pericentromeric C band and autosomal NORs. Triple staining techniques including CMA3/DA/DAPI also provided useful information for differentiating these Conoderus species. These techniques revealed unique GC-rich heterochromatin associated with NORs in C. scalaris and C. stigmosus and CMA3-heteromorphism in C. scalaris and C. ternarius.
authors.affiliation: Departamento de Biologia, Instituto de Biociências, Universidade Estadual Paulista-UNESP, Rio Claro, Av. 24-A, n 1515, CP 199, CEP 13506-900, Rio Claro, São Paulo, Brazil. marieb@rc.unesp.br
authors.forename: Marielle Cristina
authors.initials: MC
authors.lastname: Schneider
authors.forename: Mara Cristina
authors.initials: MC
authors.lastname: Almeida
authors.forename: Simone Policena
authors.initials: SP
authors.lastname: Rosa
authors.forename: Cleide
authors.initials: C
authors.lastname: Costa
authors.forename: Doralice Maria
authors.initials: DM
authors.lastname: Cella
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002871:Chromosome Banding; D002875:Chromosomes / Q000235:genetics; D001517:Coleoptera / Q000145:classification / Q000235:genetics*; D004171:Diploidy; D005260:Female; D007211:Indoles; D007621:Karyotyping; D008297:Male; D008540:Meiosis / Q000235:genetics; D008938:Mitosis / Q000235:genetics; D012730:Sex Chromosomes / Q000235:genetics; D012835:Silver Nitrate; D013045:Species Specificity; D013194:Staining and Labeling
chemical_list: D007211:Indoles; C007293:DAPI; D012835:Silver Nitrate