Research Article

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

Published: July 21, 2009
Genet. Mol. Res. 8 (3) : 831-839 DOI: https://doi.org/10.4238/vol8-3gmr598
Cite this Article:
(2009). Occurrence of multiple nucleolus organizer regions and intraspecific karyotype variation in Scaptotrigona xanthotricha Moure (Hymenoptera, Meliponini). Genet. Mol. Res. 8(3): gmr598. https://doi.org/10.4238/vol8-3gmr598
1,241 views

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 CMA3-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.

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 CMA3-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.