Abstract: Drosophila melanogaster is a widely used model organism for genetic dissection of developmental processes. It is an ideal multicellular organism for the rapid toxicological screening of substances for mutagenicity. Boule gene was shown to be a key regulator of meiosis in Drosophila. Boule-deficient fruit flies are infertile and display meiotic arrest in the male germ cells. Investigation of the impact of some nitrogenous fertilizers on the expression of Drosophila boule gene had been performed. Newly hatched larvae were treated with the LC25 and LC50 of the three tested nitrogenous fertilizers Urea, Ammonium nitrate and Calcium nitrate. The study includes the isolation and molecular characterization of the Drosophila boule gene homolog to the human DAZ gene. Total RNA have been isolated from untreated and treated D. melanogaster adult male flies. Fragments of the boule gene were recovered with RT-PCR for sequencing. Treated and untreated Drosophila melanogaster boule gene express the same pattern of transcripts. The sequence of the boule fragments of the treated adult males with the LC25 and LC50 of the three tested nitrogenous fertilizers showed different types of mutations such as substitution, deletion and insertion mutations. These results indicate that the three nitrogenous fertilizers used posses mutagenic potentialities. The mutagenic activity is due to their Nitrogen (N) content. Another possible interpretation for the mutagenicity of the tested compounds is the ability of nitrogenous fertilizers to methylate DNA resulting in different types of genetic alterations. Analysis of these mutations should provide insight into the genetic networks that control male fertility in Drosophila and other organisms, including humans.