Meiotic recombination in the ZW pair of a tinamid bird shows a differential pattern compared to neognaths

PIGOZZI MI; SOLARI AJ

GENOME

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Año: 2005 vol. 48 p. 286 - 290

0831-2796

Abstract: The tinamid bird Nothura maculosa, along with other species of the order Tinamiformes and all of the existent ratites, form the infraclass Paleognathae, the most primitive living birds. Previous work has shown that in all studied Neognathae, the ZW pair shows strictly localized recombination in a very short pseudoautosomal region, while in paleognath birds, the ZW pairs have mostly free recombination. The present observations show that the ZW pair of N. maculosa has a recombination pattern departing from both neognaths and other Paleognath birds, as there is a single crossover but occurring at random points along a significant part of the long arm of the W chromosome. This recombination pattern agrees with the presence of intercalary and terminal heterochromatin in the W chromosome, suggesting an exceptional, additional step of recombination suppression.