Occurrence of multiple nucleolus organizer regions and intraspecific karyotype variation in Scaptotrigona xanthotricha Moure (Hymenoptera, Meliponini)

• Published in: Genetics and molecular research Vol. 8; no. 3; pp. 831 - 839
• Main Authors: Duarte, O.M.P, Martins, C.C.C, Waldschmidt, A.M, Costa, M.A
• Format: Journal Article
• Language: English
• Published: Brazil 01.01.2009
• Subjects: Animals; Apidae; Chromosome Banding; chromosomes; Female; Genetic Variation; geographical variation; Geography; heterochromatin; Hymenoptera - genetics; Karyotyping; Male; Metaphase; nucleolus organizer region; Nucleolus Organizer Region - genetics; rain forests; Scaptotrigona xanthotricha; Species Specificity; stingless bees; Brazil
• ISSN: 1676-5680; 1676-5680
• DOI: 10.4238/vol8-3gmr598

Scaptotrigona xanthotricha has a wide geographic distribution in the Brazilian Atlantic rainforest. One population from southeast and two from northeast Brazil were analyzed and were found to have chromosome polymorphisms. Although the chromosome number 2n = 34 is conserved in this species, karyotypic analysis revealed clear differences between the three populations. Congruent and ubiquitous multiple nucleolus organizer regions, heterochromatin and CMA(3)-positive blocks were found. The variations suggest that this species is in a process of genetic differentiation. This differentiation process might have been enhanced by restricted nesting preferences, combined with recent extensive fragmentation of the Atlantic rainforest, which limits gene flow between populations.