Polymorphism of Sooty-fronted Spinetail (Synallaxis frontalis Aves: Furnariidae): Evidence of chromosomal rearrangements by pericentric inversion in autosomal macrochromosomes

Abstract

The Passeriformes is the most diverse and cytogenetically well-known clade of birds, comprising approximately 5,000 species. The sooty-fronted spinetail (Synallaxis frontalis Aves: Furnariidae) species, which belongs to the order Passeriformes, is typically found in South America, where it is widely distributed. Polymorphisms provide genetic variability, important for several evolutionary processes, including speciation and adaptation to the environment. The aim of this work was to analyze the possible cytotypes and systemic events involved in the species polymorphism. Of the sampled 19 individuals, two thirds were polymorphic, an event supposedly linked to mutations resulting from genomic evolution that can be transmitted hereditarily. A chromosomal polymorphism was detected between the 1st and 3rdpairs of autosomal macrochromosomes. This type of polymorphism is related to a pericentric inversion in regions involving chromosomal rearrangements. Differently from other polymorphism studies that report a link between polymorphic chromosomes and phenotypic changes, S. frontalis did not present any morphological variation in the sampled individuals.

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

“…A possible break followed by pericentric inversion may have occurred, resulting in the changes found in biarmed chromosome, which has 2 bands in region 1 of the short arm in the two species. This is a rearrangement type that has been previously found in Treron phoenicoptera and Synallaxis frontalis by GTG-bands (Gupta and Kaul 2014;de Souza et al 2019).…”

“…Examples of this are the chromosomal rearrangements already reported by GTG and RBG bands in Gallus gallus (Galliformes), which identified a paracentric inversion in the long arm of chromosome 2 (Nanda et al 1994). Chromosomal polymorphisms were identified by GTG bands in Synallaxis frontalis (Passeriformes), where pericentric inversion involving the first and third pairs was observed (de Souza et al 2019), and in Treron phoenicoptera (Columbiformes) in the first and second pairs (Gupta and Kaul 2014).…”

“…For this differentiation, a possible paracentric inversion and deletion may have occurred. In Synallaxis frontalis species, there is a pericentric inversion involving the first and third pairs (de Souza et al 2019). Nevertheless, this diversity of rearrangements involving chromosomes 1, 2, and 3 is not restricted to Passeriformes.…”