ABSTRACT
Molecular cytogenetics has made important contributions to genomic studies of fishes. Perhaps one of the most useful applications is the ability to document the existence of duplicate loci and to determine if duplicates are found in tandem or on different chromosomes. This chapter summarizes the genome mapping projects that are completed or in progress for fish species. It also summarizes on mapping of single copy genes, identification and mapping of sex chromosomes, production of chromosome specific probes and application of these probes to chromosome evolution. Several chromosomes or chromosome-arm specific probes have been made for rainbow trout and one made to the largest acrocentric chromosome pair also hybridizes to the telomere of the homologous metacentric chromosome pair. The paint probes made from rainbow trout can be applied to all species of salmonids examined to date, so if a complete set were made, they could be used to trace chromosome evolution in salmonids.
