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J. Biotec. Biodivers. v. 5, N.2: pp. 140-147 May 2014

chromosomes of Mimus saturninus present the Z and W typical for Carinatas, which usually have significant differences in size and morphology as it is showed in other studies (Gunski et al. 2000,Stiglec et al. 2007, Correia et al. 2009). The GTG-banding was similar to Gallus gallus and other bird species studied by Takagi and Sasaki (1974). Takagi and co-worker(1974) have shown an almost identical G-banding

pattern in the three first pairsin nine species of different orders (Casuariiformes, Rheiformes,

Ciconiiformes, Pelecaniformes, Anseriformes,

Falconiformes, Phoenicopteriformes, Gruiformes and Galliformes). In Cathartiformes, the GTG-banding also showed very similar patterns in three species of theCathartidae family (Tagliarini et al. 2009).

Figure 2 – Characterization of Chalk-browed Mockingbird ( Mimus saturninus ) karyotype by classical cytogenetics: (a) female metaphase by conventional Giemsa-staining, arrows show the Z and W sex chromosomes with differences in size and morphology; (b) male metaphase by conventional Giemsa-staining, arrows show the Z sex chromosomes; (c) Complete karyotype, 2n=80; (d) Macrochromosomes 1-5 GTG-banded.

The only species of the Mimidae family described ( Toxostomarufum , 2n=78) has a diploid number close to the Mimus saturninus , however, it differs in the morphology of some macrochromosomes pairs (fourth to tenth) and in the Z sex chromosome (metacentric). The W sex chromosome from Toxostomarufum was not identified (Jovanovic 1969).

In the CBG-banding we observed positive staining in the pericentromeric region of most macrochromosomes and microchromosomes, including in the Z sex chromosome, while in the W sex chromosome it was totally heterochromatic (Fig. 3). According to the classification proposed by Imai (1991) the species studied here is included in the Type I, once it has only pericentromeric CBG-banding,