Spiroplasma (Mollicutes) is one of the heritable bacterial endosymbionts of Drosophila species. Several strains like S. poulsonii manipulate host reproduction in a selfish manner. When females of D. melanogaster are infected with natural S. poulsonii strain MSRO (melanogaster sex ratio organism), only male offspring are killed during embryogenesis, and this phenomenon is called male-killing. To understand the molecular mechanism of male-killing, we compared gene expression profiles between MSRO-infected and uninfected embryos of D. melanogaster by using RNA-sequencing (RNA-seq). For embryonic sexing, we employed a transgenic reporter strain Sex-lethal (Sxl)-Pe-EGFP, which expresses GFP only in females. We collected female and male embryos at stage 10-11, when abnormal apoptosis associated with male-killing starts to occur in male progenies. For each sample, we analyzed three biological replicates.