Genome size variation inMeliponaspecies (Hymenoptera: Apidae) and sub-grouping by their DNA content

Abstract

The stingless bees of the genus Melipona comprise a group with approximately 40 Neotropical species. Despite their ecological and economic importance, the size of the genomes of these species remains poorly known. Thus, the present study measured the DNA content of 15 Melipona species. The mean genome size (1C) of the females ranged from 0.27 pg to 1.38 pg, with increments of, approximately, 0.12 pg. It was possible to recognize two groups of species: the first presented relatively low DNA content (average = 0.29 pg), while the second showed high DNA content (average = 0.98 pg). This result corroborates the cytogenetic classification of these species into two groups, one of them comprising species with a low heterochromatin content (<50%), and the other species with high heterochromatin content (>50%). Amongst the groups with low and high DNA content, there was no significant correlation between the DNA content and the size of the bees. The data obtained may aid in the selection of species which are suitable for sequencing projects, besides providing an overview of the diversity in the genome size of the Melipona genus. flow cytometry / genome size / Hymenoptera / Melipona

Repetitive DNAs in Melipona scutellaris (Hymenoptera: Apidae: Meliponidae): chromosomal distribution and test of multiple heterochromatin amplification in the genus

“…The differences in the heterochromatin amounts and distribution are remarkable aspects of Melipona , and based in these differences, Rocha and Pompolo (1998) divided the genus into two groups (see introduction). Species with high heterochromatic contents also display larger genome sizes, such as M. scutellaris , whose genome is 1.08 pg (Tavares et al 2010). The notion of the amplification of repetitive DNAs, which is associated with large heterochromatic blocks, is reinforced in this work by the analysis of the DOP-PCR and C 0 t -DNA fraction probe hybridization that labeled the same regions corresponding to heterochromatin (Figure 2b, c).…”

Intraspecific variation in the karyotype length and genome size of fungus-farming ants (genus Mycetophylax), with remarks on procedures for the estimation of genome size in the Formicidae by flow cytometry

“…Most of the estimates of genome size available for formicides have been obtained using Drosophila melanogaster as the internal standard [ 6 , 34 ], although Cardoso et al [ 14 ] also used females of Scaptotrigona xantotricha to analyze hymenopterans, in particular, stingless bees [ 35 – 37 ]. In the present study, D .…”

“…By contrast, only Lopes et al [37] and Tavares et al [35,36] have estimated the genome size of Scapitotrigona xantotricha, and found a difference in the values recorded for males and females. This is probably because bees, like ants, have a haplodiploid sex determination system, with haploid males and diploid females (workers and queens).…”

“…These standards are Drosophila melanogaster and Scaptotrigona xantotricha (e.g. [6,14,[34][35][36] [37]. Both these standards were tested so that we could determine the internal reference standard for estimating the nuclear genome size of the ants collected in the present study.…”

“…Most of the estimates of genome size available for formicides have been obtained using Drosophila melanogaster as the internal standard [6,34], although Cardoso et al [14] also used females of Scaptotrigona xantotricha to analyze hymenopterans, in particular, stingless bees [35][36][37]. In the present study, D. melanogaster proved to be a good internal standard for the ants analyzed, and was more appropriate than S. xantotricha, due primarily to the small 1C value of D. melanogaster, which avoids potential overlap between the peaks of the target species and the internal standard.…”