Cytogenetic characterization of two species of Frieseomelitta Ihering, 1912 (Hymenoptera, Apidae, Meliponini)

Abstract

The cytogenetic analysis of Frieseomelitta dispar and F. francoi revealed the chromosome numbers 2n = 30 and n = 15 and a karyotypic formula 2K = 4M+2Mt+4A+20AM. The number of chromosomes observed was consistent with those reported for other Frieseomelitta species. The occurrence of the Mt chromosome and other features of the karyotype formulae suggest a close relationship between F. dispar, F. francoi and F. varia. Nevertheless, it was possible to differentiate the karyotypes of the species by DAPI/CMA3 staining, which revealed GC-rich regions on two chromosome pairs of F. dispar: one acrocentric and one pseudoacrocentric. In F. francoi, the same kinds of regions were observed on a pair of metacentrics and on a pair of acrocentrics. Our analysis also confirmed the chromosome number conservation in Frieseomelitta and suggests that infrequent pericentric inversion could constitute a synapomorphy for the group including F. dispar, F. francoi, and F. varia.

Heterochromatin Distribution and Chromosomal Mapping of Microsatellite Repeats in the Genome ofFrieseomelittaStingless Bees (Hymenoptera: Apidae: Meliponini)

“…2). The karyotype formula of F. dispar (2K = 4M + 2M t + 6A + 18A M ) herein described differs from that previously reported (Carvalho & Costa 2011).…”

“…The karyotype formula of F. francoi (2K = 4M + 2M t + 4A + 20A M ) corroborates the report by Carvalho and Costa (2011).…”

“…All female specimens of Frieseomelitta sampled here shared 2n = 30 chromosomes, as reported in other congeneric species (Rocha et al 2003;Carvalho & Costa 2011). Similarly, the constitutive heterochromatin was distributed over centromeric, pericentromeric, and telomeric regions in the 6 analyzed species, with conspicuous C-bands in 1 arm of most chromosomes (Fig.…”

“…Cytogenetic reports are important to infer evolutionary processes and assess the genomic organization of species, thus being informative to taxonomy and systematics (Sumner 2003). Approximately 65 stingless bee species have been cytogenetically analyzed so far (Cristiano et al 2014), but only 5 of them include the genus Frieseomelitta, in which only conventional techniques (Giemsa staining, C-banding, and base-specific fluorochrome staining), have been applied (Rocha et al 2003;Carvalho & Costa 2011). Even though the number of cytogenetic studies in meliponines is underrepresented, the chromosomal data reported so far demonstrate a high amount of heterochromatin present in most species (Rocha et al 2003).…”

“…Alternatively, microsatellites probes already have been produced and successfully tested to evaluate heterochromatin composition in several groups of animals and plants (Kubat et al 2008;Martins et al 2013;Parise-Maltempi et al 2013;Lopes et al 2014). Cytogenetic data in Frieseomelitta are restricted to conventional analyses (Giemsa-staining and C-banding) and staining with base-specific fluorochromes (Rocha et al 2003;Carvalho& Costa 2011). Once the accumulation of repetitive DNA sequences plays a key role in chromosomal evolution (Charlesworth et al 2005), serving as hotspots for chromosomal rearrangements, the chromosomal mapping of these sequences is useful to infer evolutionary pathways for distinct animal groups.…”