DNA PROBES FOR 2 MICROSPORIDIA, NOSEMA-BOMBYCIS AND NOSEMA-COSTELYTRAE

Two DNA fragments which hybridize specifically with DNA of Nosema bomb ycis and Nosema costelytrae, respectively, were obtained from genomic DNA of each microsporidian species and sequenced. Neither fragment hyb ridized with genomic DNA from four other microsporidian isolates teste d: Nosema apis, Vairimorpha sp. from cabbage white butterfly (Pieris r apae), and two isolates of Vauraia oncoperae, one from New Zealand gra ss grubs, Costelytra zealandica, and another from porina caterpillars, Wiseana spp. The probe for N. bombycis did not hybridize with genomic DNA from N. costelytrae or with DNA from silkworms (Bombyx mori), the primary insect host of this microsporidium. Likewise, the probe for N . costelytrae did not hybridize with genomic DNA from N. bombycis or w ith DNA from grass grubs (C. zealandica). Both fragments were AT-rich (59 and 79% of total bases, respectively), had G+C/A+T ratios of 0.70 and 0.25, respectively, and represented repeated sequences dispersed t hroughout the genome. (C) 1995 Academic Press, Inc.