Cytogenetic and Molecular Characterization of Three Mimetic Species of the GenusAlagoasaBechyne 1955 (Coleoptera: Alticinae) from the Neotropical Region

摘要

Coleoptera is a mega-diverse order, but only about 1% of its species have been analyzed cytogenetically. In this order, the subfamily Alticinae presents many identification problems, mainly due to the occurrence of mimicry. The objective of this work was to cytogenetically characterize 3 very similar species of the genusAlagoasa(A. pantina,A.areata, andA.scissa). We used classical and molecular cytogenetic as well as molecular genetic techniques. All 3 species showed a diploid chromosome number of 2n = 22 (20+X+y), but differences in the morphology of the chromosomes. All had a meiotic formula of 2n = 10II+X+y and an X+y sex determination system with giant, fully asynaptic sex chromosomes, concordant characteristics observed in the subtribe Oedionychina. FISH demonstrated the presence of 18S and 5S rDNA clusters in 1 pair of autosomes, syntenic and colocalizing in the 3 analyzed species. However, inA. areata, heteromorphism between the cistrons was observed. The telomeric (TTAGG)(n) probe showed signals in all 3 species, with proximal signals in the X and dispersed signals in the y chromosome ofA. areata, and 2 proximal signals in the X chromosome ofA. scissa. Molecular analysis of theCOIgene indicated that they are 3 distinct species, corroborating the observed cytogenetic characteristics.