Comparative cytogenetics in three species of Wood-Warblers (Aves: Passeriformes: Parulidae) reveal divergent banding patterns and chromatic heterogeneity for the W chromosome

Abstract

Chromosomal rearrangements are an important process in the evolution of species. It is assumed that these rearrangements occur near repetitive sequences and heterochromatic regions. Bird karyotypes have diverse chromosomal band patterns and have been used as the parameters for phylogenetic studies. Although the group has a high diversity of species, no more than 12% has been analysed cytogenetically, and the Parulidae family are extremely underrepresented in these studies. The aim of this study was to detect independent or simultaneous chromosomal rearrangements, and also analyze chromosomal banding convergences and divergences of three species of Wood-Warblers: Myiothlypis leucoblephara, Basileuterus culicivorus, and Setophaga pitiayumi. Our CBG-band results reveal an unusual W sex chromosome in the three studied species, containing a telomeric euchromatic region. The GTG and RBG bands identify specific regions in the macrochromosomes involved in the rearrangements. Our cytogenetic data confirm the identification of speciation processes at the karyotypic in this group.

Keywords

• Chromosome Evolution
• Karyotype
• Diploid Number
• Chromosomal Banding
• Constitutive Heterochromatin