Cloning and characterization of a histone gene family in Tilapia fish

Genomic organization and expression of a histone gene family in the Tilapia (Cichlidae) fish was determined. A genomic library was prepared; four clones containing the complete set of core histones were analyzed. These clones differed significantly in their restriction maps, although three of them revealed a uniform internal gene arrangement of the core histone genes. Differential expression between two of the cloned clusters was observed when the hybridization pattern of those clusters to various RNA preparations was compared. The copy number of histone genes was estimated to be 100 to 110 for haploid Tilapia genome.