Nucleolar organizer regions in Sittasomus griseicapillus and Lepidocolaptes angustirostris (Aves, Dendrocolaptidae): evidence of a chromosome inversion

Abstract

Cytogenetic studies in birds are still scarce compared to other vertebrates. Woodcreepers (Dendrocolaptidae) are part of a highly specialized group within the Suboscines of the New World. They are forest birds exclusive to the Neotropical region and similar to woodpeckers, at a comparable evolutionary stage. This paper describes for the first time the karyotypes of the Olivaceous and the Narrow-billed Woodcreeper using conventional staining with Giemsa and silver nitrate staining of the nucleolar organizer regions (Ag-NORs). Metaphases were obtained by fibular bone marrow culture. The chromosome number of the Olivaceous Woodcreeper was 2n = 82 and of the Narrow-billed Woodcreeper, 2n = 82. Ag-NORs in the largest macrochromosome pair and evidence of a chromosome inversion are described herein for the first time for this group.

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

“…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 . Two species of the Formicariidae family ( Furnariidae sister group) also present the first two pairs with similar size, so the fission of the GGA2 chromosome may be a characteristic shared by the species of Parvordem Furnariida ( Ledesma et al 2002 , Selvatti et al 2015 ).…”

“…The genome of S. frontalis shows a chromosomal organization typical for Class Aves and order Passeriformes ( Gunski et al 2000 , Santos and Gunski 2006 , Kretschmer et al 2014 ), with 2n=82. The two species of the family Furnariidae described cytogenetically so far, Sittasomus griseicapillus and Lepidocolaptes angustirostris , also have the same diploid number found in S. frontalis , but with variations in the morphologies of some macrochromosomes ( Barbosa et al 2013 ). The Z chromosome of S. frontalis is submetacentric, unlike the acrocentric morphology found in S. griseicapillus , and L. angustirostris .…”

“…Most species show diploid numbers (2n) ranging between 76–80 chromosomes, although there are exceptions, such as Platyrinchus mystaceus Vieillot, 1818 a Suboscine species belonging to the Platyrinchidae family, which has 60 chromosomes ( Gunski et al 2000 , Santos and Gunski 2006 , Correia et al 2009 ). Among the Furnariidae , only two species have been described cytogenetically - Sittasomus griseicapillus Vieillot, 1818 and Lepidocolaptes angustirostris Vieillot, 1818, both with 2n=82 ( Barbosa et al 2013 ).…”

Comparative Cytogenetics between Two Important Songbird, Models: The Zebra Finch and the Canary

“…For instance, in birds, information on the number and distribution of 18/28S is available for a limited number of species, usually using the Ag-NOR technique. In most of these 18/28S rDNA clusters are found on only one pair, usually a microchromosome, although there are already well documented variations [ 36 – 39 ]. For Passeriformes, most species analyzed show only one pair of microchromosomes bearing 18/28S rDNA [ 22 , 40 ], such as we found in zebra finch and canary.…”

Karyotype Evolution in Birds: From Conventional Staining to Chromosome Painting

“…Because of their small size, no G-banding patterns are seen in the smallest macrochromosomes or in microchromosomes. Hence, other chromosomal markers, based on the distribution of constitutive heterochomatin or on the sites of nucleolar organization regions (NORs), have been important in studying evolutional relationships [ 35 ].…”