Occurrence and Origin of Supernumerary Chromosomes in <b><i>Partamona</i></b> (Hymenoptera: Apidae: Meliponini)

Abstract

Samples from 861 colonies of 12 Partamona species from 125 Brazilian localities were analysed for a SCAR marker specific to the B chromosomes of P. helleri. We identified the SCAR marker in 6 of the 12 species analysed, including 2 (P. gregaria and P. chapadicola) from the pearsoni clade. This is the first report on the presence of this marker in Partamona species that are not included in the cupira clade, which indicates that the B chromosomes probably are more widespread in this genus than previously thought. The analysis revealed a high frequency of the SCAR marker in the samples of P. helleri (0.47), P. cupira (0.46), and P. rustica (0.29), and a low frequency in P. aff. helleri (0.06). The frequency of the marker in P. helleri was correlated with the latitude of the sampling locality, decreasing from north to south. Sequence data on the SCAR marker from 50 individuals of the 6 species in which the presence of this marker was shown revealed a new scenario for the origin of the B chromosomes in Partamona.

Karyotypic description of the stingless bee Melipona quinquefasciata Lepeletier, 1836 (Hymenoptera, Meliponini) with emphasis on the presence of B chromosomes

“…Finally, in bees, B chromosomes have been reported in the genera Melipona Illiger, 1806 ( M.rufiventris Lepeletier, 1836 and M.quinquefasciata Lepeletier, 1836), Partamona Schwarz, 1939 ( P.cupira Smith, 1863, P.helleri Friese, 1900 and P.rustica Pedro et Camargo, 2003) and Tetragonisca Moure, 1946 ( T.fiebrigi Schwarz, 1938) (revision in Tavares et al 2017). They are also probably present in the species P.criptica Pedro et Camargo, 2003, P.seridoensis Pedro et Camargo, 2003, P.gregaria Pedro et Camargo, 2003, P.chapadicola Pedro et Camargo, 2003 and P.aff.helleri since molecular analysis demonstrated the presence of a sequence-characterized amplified region (SCAR) marker specific to the B chromosome of P.helleri in these genomes (Correia et al 2014, Tosta et al 2014, Machado et al 2016). However, for these species, the presence of B chromosomes needs to be confirmed through cytogenetic techniques, as does the variation found in the sawfly Tenthedrobrevicornis (Konow, 1886) (Sanderson 1970) and in the Braconidae, Aphidiuservi , Halliday, 1834 (Gokhman and Westendorff 2003).…”