In situ hybridization mapping of histone genes in Anopheles albimanus

The histone genes of Anopheles albimanus were mapped by in situ hybridization to 6 bands in Region 34A on the right arm of chromosome 3. A genomic library was made by cloning fragments of 15 to 23 kb (derived from partial EcoRI digestion) into the phage vector, EMBL4, and probed with the histone gene repeat of Drosophila melanogaster. Thirty-two phages containing histone gene sequences were isolated from about 10(5) plaque-forming units (pfu). Complete EcoRI digestion of DNA from 5 of the 32 recombinant phages and the genomic DNA of An. albimanus yielded a single 3.84-kb fragment that contained sequences homologous to the 5 histone genes of D. melanogaster. This 3.84-kb unit of mosquito histone genes was subcloned into puc19 plasmid, and the resulting clone (palbi34A) was used for in situ hybridization to salivary gland chromosomes.