Schematic representation of the origin of the multiple sex chromosome system and a formation of the gametes during the meiosis I in Pygoscelis adeliae a The chromosomal translocation, which involving a heterochromatic segment of the ancestral chromosome Z2 with a terminal portion of the q arm of W chromosome b The meiosis in females and males of proposing the balanced gametes formation.

 
 
  Part of: Gunski RJ, Cañedo AD, Garnero ADV, Ledesma MA, Coria N, Montalti D, Degrandi TM (2017) Multiple sex chromosome system in penguins (Pygoscelis, Spheniscidae). Comparative Cytogenetics 11(3): 541-552. https://doi.org/10.3897/CompCytogen.v11i3.13795