Chromosome Painting in Tyrant Flycatchers Confirms a Set of Inversions Shared by Oscines and Suboscines (Aves, Passeriformes)

Abstract

Tyrannidae is the largest family of Passeriformes in the Neotropical region. However, despite an interesting chromosomal diversity, there are only few cytogenetic studies of this family, and most of these are based on conventional cytogenetics. Hence, we analyzed here the chromosomal diversity and karyotypical evolution of this group by chromosome painting in 3 different species - Pitangus sulphuratus, Serpophaga subcristata, and Satrapa icterophrys - and make comparisons with previous data. In addition to chromosome painting with Gallus gallus (GGA) and Leucopternis albicollis (LAL) probes, karyotypes were analyzed by conventional staining, C-banding, and FISH with 18S rDNA and telomeric probes. Although this family is characterized by extensive chromosomal variation, we found similar karyotypes and diploid numbers ranging from 2n = 80 in P. sulphuratus to 2n = 82 in S. subcristata and S. icterophrys. Constitutive heterochromatin was located centromerically in all 3 species. Clusters of 18S rDNA were present in 1 pair of microchromosomes, except in S. subcristata, where 2 pairs of microchromosomes were labeled. No interstitial telomeric sequences were detected. GGA and LAL whole-chromosome probes revealed the occurrence of fissions and both paracentric and pericentric inversions commonly seen in other Passeriformes. In general terms, tyrants show the typical karyotype found in Passeriformes, suggesting that the observed rearrangements occurred before the division of the suborders Oscines and Suboscines.

Multidirectional chromosome painting in Synallaxis frontalis (Passeriformes, Furnariidae) reveals high chromosomal reorganization, involving fissions and inversions

“…Probably this characteristic is shared by all Passeriformes , since it was found in species of both suborders, Oscines (14 species) and Suboscines (5 species, including S. frontalis ). The presence of this characteristic in the genome of S. frontalis is important for the confirmation of this hypothesis, since only four species of the Suboscines suborder had been studied by chromosome painting, and now we can verify that this characteristic is shared between two species in different families, Tyrannidae and Furnariidae ( Kretschmer et al 2015 , Rodrigues et al In press ). In addition, the Furnariidae family is more basal than the family Tyrannidae ( Selvatti et al 2015 ).…”

“…Unlike the fission of the GGA1 chromosome, the fission of the GGA2 chromosome has been described previously in only one species of the order Passeriformes , Satrapa icterophrys Vieillot, 1818 ( Rodrigues et al In press ). This rearrangement is probably shared with two other species of the Furnariidae family described by Barbosa et al (2013) , because in these species the two first autosomes pairs are similar in size, a fact also observed in S. frontalis .…”

“…Only the first two pairs (GGA1 and GGA2) are not conserved, due to the occurrence of fissions, and correspond to SFR1 and SFR5, SFR3 and SFR7 pairs, respectively. The fission of the ancestral chromosome 1 has been found in all species of the order Passeriformes studied to date (19 species, including S. frontalis ) ( Guttenbach et al 2003 , Derjusheva et al 2004 , Itoh and Arnold 2005 , Nanda et al 2011 , Kretschmer et al 2014 , 2015 , dos Santos et al 2015 , 2017 , Rodrigues et al In press ). Probably this characteristic is shared by all Passeriformes , since it was found in species of both suborders, Oscines (14 species) and Suboscines (5 species, including S. frontalis ).…”

“…Fourteen species of the suborder Oscines have been analyzed by chromosome painting ( Guttenbach et al 2003 , Derjusheva et al 2004 , Itoh and Arnold 2005 , Nanda et al 2011 , Kretschmer et al 2014 , dos Santos et al 2015 , 2017 ), and only four species of Suboscines ( Kretschmer et al 2015 , Rodrigues et al In press ). Eight of these species were compared using only whole chromosome probes of Gallus gallus Linnaeus, 1758 (GGA) ( Guttenbach et al 2003 , Derjusheva et al 2004 , Itoh and Arnold 2005 , Nanda et al 2011 ).…”

“…The results have shown mostly the same syntenic groups found in the putative avian ancestral karyotype (PAK) proposed by Griffin et al (2007) , with the exception of PAK1 (GGA1), which is split into two chromosome pairs, representing a synapomorphy shared by all the species of Passeriformes analyzed so far. However, the other ten species were analyzed with whole chromosome probes from two different species – GGA and Leucopternis albicollis Latham, 1790 (LAL), an Accipitridae with 2n=66, in which syntenic groups corresponding to PAK pairs 1, 2, 3 and 5 each correspond to 2–5 different pairs ( de Oliveira et al 2010 , Kretschmer et al 2014 , 2015 , dos Santos et al 2015 , 2017 , Rodrigues et al In press ). This approach revealed additional rearrangements in which chromosome pairs corresponding to PAK1p and PAK1q were reshuffled through a series of paracentric and pericentric inversions in both Oscines and Suboscines species, suggesting that these rearrangements had occurred early in the history of Passeriformes , before their split into two suborders ( Kretschmer et al 2014 , 2015 , dos Santos et al 2015 , 2017 ).…”