title: Occurrence of multiple nucleolus organizer regions and intraspecific karyotype variation in Scaptotrigona xanthotricha Moure (Hymenoptera, Meliponini).
abstract: 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.
authors.affiliation: Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Ilhéus, BA, Brasil.
authors.forename: O M P
authors.initials: OM
authors.lastname: Duarte
authors.forename: C C C
authors.initials: CC
authors.lastname: Martins
authors.forename: A M
authors.initials: AM
authors.lastname: Waldschmidt
authors.forename: M A
authors.initials: MA
authors.lastname: Costa
mesh_terms: D000818:Animals; D002871:Chromosome Banding; D005260:Female; D014644:Genetic Variation; D005843:Geography; D006927:Hymenoptera / Q000235:genetics*; D007621:Karyotyping; D008297:Male; D008677:Metaphase; D009697:Nucleolus Organizer Region / Q000235:genetics*; D013045:Species Specificity