Camargo, Crisley de [UNESP]Lisle Gibbs, H.Costa, Mariellen C.Silveira, Luis F.Rainho, Claudia A. [UNESP]Ribolla, Paulo E. M. [UNESP]Wasko, Adriane P. [UNESP]Francisco, Mercival R.2018-11-262018-11-262017-11-01Journal Of Avian Biology. Hoboken: Wiley, v. 48, n. 11, p. 1475-1480, 2017.0908-8857http://hdl.handle.net/11449/163526In birds, there are two main models for the determination of sex: the Z Dosage' model in which the number, or dose, of Z chromosomes determines sex, and the Dominant W' model which argues that a specific gene in the W chromosome may influence Z gene expression and determine sex. The best evidence for W determination of sex comes from birds with 2 copies of the Z chromosome paired with a single W (e.g. ZZW) which are nonetheless females. Here, we expand the species where such a mechanism may operate by reporting a case of a triploid Neotropical passerine bird with sexually dimorphic plumage, the SAo Paulo marsh antwren Formicivora paludicola. Evidence from 17 autosomal unlinked microsatellite loci, and CHD1 sex-linked locus, indicate that this individual is a 3n ZZW triploid with intermediate plumage pattern. This example expands our knowledge of sex determination mechanisms in birds by demonstrating that both the W and the two Z chromosomes affect the expression of morphological secondary sexual traits in a non-galliform bird.1475-1480engArtigo10.1111/jav.01504WOS:000416331100015Acesso restrito192686391737890935771497484568800000-0003-4600-03670000-0001-8735-6090