Cis-regulatory elements affecting the Nanos gene promoter in the germline stem cells

Abstract: Drosophila Nanos gene plays an important role in stem cell maintenance and body patterning. With the purpose of understanding the cis-regulatory machinery involved in the transcription of the nanos gene in the germline stem cells, we examined its promoter fragment from +97 to −708 relative to the transcription start site and identified enhancer elements located between position −108 and +97. Experiments with transgenic flies revealed that the minimal promoter (from −108 to +20) is sufficient in the germline stem cells for the GFP expression in transgenic Drosophila. Moreover, the flag-tagged nanos protein blotting experiments revealed that a short promoter fragment plus some sequences of the nos 5′UTR spanning −108 to +97 could efficiently drive the expression of the flag-tagged [Nos-mRNA-nos3′UTR] transgene in transgenic flies indicating that the cis-regulatory elements located between positions −108 and +97 of the nanos promoter are sufficient to fully transcribe the nanos mRNA. Deletion of the identified cis-acting sequences from the promoter rendered it non-functional as it could no longer transcribe the nanos mRNA in transgenic flies thus revealing the importance of these sequences for the transcription of the nanos gene. [Copyright &y& Elsevier]