title: Molecular sexing of unusually  large numbers of Spheniscus magellanicus (Spheniscidae) washed ashore  along the Brazilian coast in 2008.
abstract: There  have been few studies on Magellanic penguins (Spheniscus magellanicus).  In 2008, these penguins washed ashore along the Brazilian coast in unusually  high numbers, some reaching as far as northeast Brazil. As Magellanic penguins  show little sexual dimorphism, sex determination by morphological features is  not accurate. Here, we tested a molecular procedure for sexing specimens of S.  magellanicus washed ashore along the coasts of Sergipe, Rio de Janeiro and  Rio Grande do Sul in 2008, comparing the sex ratio between these localities.  Tissue samples were collected from 135 dead, beached specimens. We carried out  total genomic DNA extraction and CHD-Z/CHD-W gene amplification by PCR using P2  and P8 primers. Amplicons were separated by 12% acrylamide gel electrophoresis.  We found a greater proportion of females (70%). Sex could be determined because  females have two intronic regions of CHD gene of different size in the sex  chromosomes, visualized as two bands on the gel (380 and 400 bp approximately),  while males have only one (400 bp). Therefore, this method proved to be  effective and sensitive for sex determination of S. magellanicus individuals.  Data on sex ratios are useful for understanding the dynamics and ecology of  Magellanic penguin populations.
authors.affiliation: Laboratório de Genética Marinha, Departamento de Genética, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brasil. est.cardinot@gmail.com
authors.forename: E C
authors.initials: EC
authors.lastname: Reis
authors.forename: R M
authors.initials: RM
authors.lastname: Aires
authors.forename: J F
authors.initials: JF
authors.lastname: Moura
authors.forename: C A R
authors.initials: CA
authors.lastname: Matias
authors.forename: M
authors.initials: M
authors.lastname: Tavares
authors.forename: P H
authors.initials: PH
authors.lastname: Ott
authors.forename: S
authors.initials: S
authors.lastname: Siciliano
authors.forename: G
authors.initials: G
authors.lastname: Lôbo-Hajdu
mesh_terms: D000818:Animals; D001938:Brazil; D017753:Ecosystem; D005260:Female; D005843:Geography; D007438:Introns / Q000235:genetics; D008297:Male; D012732:Sex Determination Analysis / Q000379:methods*; D012744:Sex Ratio; D046429:Spheniscidae / Q000235:genetics*