Poster abstracts

Poster number 90 submitted by Mohammad Marhabaie

Identifying mRNA Targets of Nanos in Drosophila melanogaster

Mohammad Marhabaie (Department Molecular Genetics and Department of Cancer Biology and Genetics, The Ohio State University), Sung Y. Kim (Department Molecular Genetics and Department of Cancer Biology and Genetics, The Ohio State University), Tammy Wharton (Department Molecular Genetics and Department of Cancer Biology and Genetics, The Ohio State University), Sushmita Ghosh (Department Molecular Genetics and Department of Cancer Biology and Genetics, The Ohio State University), Robin P. Wharton (Department Molecular Genetics and Department of Cancer Biology and Genetics, The Ohio State University)

Abstract:
Nanos (Nos) is a translational regulator that specifies abdominal segmentation of the embryo by repressing a single mRNA, hunchback (hb) in the posterior. Ectopic Nos represses a second mRNA, bicoid (bcd), in the anterior. In addition to controlling body patterning, Nos regulates other, as yet unknown mRNAs to govern diverse processes including maintenance of germline stem cells, various aspects of primordial germ cell biology, and dendritic morphology.
To identify mRNAs regulated by Nos, we have expressed a Upf1-Nos fusion protein in flies, on the assumption that the chimera would degrade rather than repress targeted mRNAs. Several lines of evidence suggested this is indeed the case; for example, embryos from females expressing Upf1-Nos have neither bcd nor hb mRNA in the anterior and develop a bicaudal body plan. Quantitation of staged embryos reveals that hb mRNA is depleted ~140-fold from Upf1-Nos embryos.
We next used RNA-seq to identify mRNAs depleted in Upf1-Nos embryos, compared to control embryos expressing Upf1 or Nos alone. These experiments reveal that 2834 mRNAs, 42% of the maternal transcriptome, are significantly depleted by Upf1-Nos. We are currently focusing on the pathways that are over-represented among abundant mRNAs that are highly depleted by Upf1-Nos, testing the biological role of Nos-dependent regulation in vivo.

Keywords: Nanos, mRNA translation