Comparative analysis of sex chromosomes in Leporinus species (Teleostei, Characiformes) using chromosome painting
1 Departamento de Biologia, Laboratório de Citogenética, Instituto de Biociências, Universidade Estadual Paulista “Julio de Mesquita Filho” - UNESP, Rio Claro, Av. 24A, 1515, CEP 13506-900 Rio Claro, SP, Brazil
2 Department of Veterinary Medicine, University of Cambridge, Cambridge Resource Centre for Comparative Genomics, Madingley Road, CB3 0ES Cambridge, UK
3 Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
BMC Genetics 2013, 14:60 doi:10.1186/1471-2156-14-60Published: 3 July 2013
The Leporinus genus, belonging to the Anostomidae family, is an interesting model for studies of sex chromosome evolution in fish, particularly because of the presence of heteromorphic sex chromosomes only in some species of the genus. In this study we used W chromosome-derived probes in a series of cross species chromosome painting experiments to try to understand events of sex chromosome evolution in this family.
W chromosome painting probes from Leporinus elongatus, L. macrocephalus and L. obtusidens were hybridized to each others chromosomes. The results showed signals along their W chromosomes and the use of L. elongatus W probe against L. macrocephalus and L. obtusidens also showed signals over the Z chromosome. No signals were observed when the later aforementioned probe was used in hybridization procedures against other four Anostomidae species without sex chromosomes.
Our results demonstrate a common origin of sex chromosomes in L. elongatus, L. macrocephalus and L. obtusidens but suggest that the L. elongatus chromosome system is at a different evolutionary stage. The absence of signals in the species without differentiated sex chromosomes does not exclude the possibility of cryptic sex chromosomes, but they must contain other Leporinus W sequences than those described here.