Occurrence of B chromosomes in Tetragonisca Latreille, 1811 (Hymenoptera, Apidae, Meliponini): A new contribution to the cytotaxonomy of the genus

• Published in: Genetics and molecular biology Vol. 34; no. 1; pp. 77 - 79
• Main Authors: Barth, Adriane, Fernandes, Anderson, Pompolo, Silvia das Graças, Costa, Marco Antônio
• Format: Journal Article
• Language: English; Portuguese
• Published: Brazil Sociedade Brasileira de Genética 01.01.2011
• Subjects: Animal Genetics; B chromosomes; BIOCHEMISTRY & MOLECULAR BIOLOGY; cytogenetics; GENETICS & HEREDITY; interspecific differentiation; stingless bees; stingless bees; B chromosomes; cytogenetics; interspecific differentiation
• ISSN: 1415-4757; 1678-4685; 1678-4685
• DOI: 10.1590/S1415-47572010005000100

Tetragonisca angustula and Tetragonisca fiebrigi have recently been listed as valid species. This study aimed to cytogenetically investigate both species, emphasizing the new registry of B chromosomes in the tribe Meliponini. We analyzed colonies of T. angustula and T. fiebrigi collected at Tangará da Serra, Mato Grosso, Brazil, through conventional Giemsa staining, C-banding, and base-specific fluorochrome staining (CMA(3)/DAPI). T. angustula showed 2n = 34 chromosomes in females and n = 17 in males, with karyotype formula 2K = 34A(M). T. fiebrigi showed numeric variation, with chromosome number varying from 2n = 34 to 2n = 36 in females and from n = 17 to n = 18 in males, with karyotype formula 2K = 32A(M)+2A(Mc) and 2K = 32A(M)+2A(Mc) + 1 or 2 B-chromosomes. The B chromosomes are heterochromatic. In T. fiebrigi, the CMA(3)/DAPI staining revealed four chromosomes with a CMA(3) positive band. All individuals from the same colony showed the same number of B chromosomes. T. angustula and T. fiebrigi showed karyotype divergence, principally due to the presence of B chromosomes, which are found only in T. fiebrigi. Our data corroborate the status of valid species for both T. angustula and T. fiebrigi, as recently proposed.