RRM - RNA binding protein - Drosophila's cytoplasmic polyadenylation element binding protein (CPEB) - functions in the transport of mRNAs coding for two essential proteins that govern polarity in the egg: Oskar, an anterior/posterior determinate and Gurken, a dorsal/ventral determinant
Low-frequency RNA-Seq exon junction(s) not annotated.
Striking stage and tissue-specific differences in 3' UTR extent apparent in RNA-seq expression profile data.
Gene model reviewed during 5.47
4.7, 3.2, 2.0 (northern blot)
915, 913 (aa); 99 (kD predicted)
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\orb using the Feature Mapper tool.
orb transcripts are detected at low levels in primary spermatocytes and are barely detected in early elongation spermatids. Robust signals are detected in more elongated spermatids at the distal ends. Transcripts localize in shallow cup-like shapes at the ends of spermatids bundles (called a cup pattern).
orb expression starts in all cystocytes between the 8- and 16- cell stage but is restricted to the oocyte in later stages.
orb protein is first observed in the cytoplasm of the oocyte and several adjacent cells in germarium region 2a just after the completion of premeiotic S-phase.
orb protein expression is restricted to the germline during oogenesis. Significant levels of orb protein are first seen in the 16-cell stage in germarium region 2. Protein is observed in all cells of the cyst but begins to preferentially localize in the presumptive oocyte. By stage S7, it is concentrated at the posterior edge of the oocyte. Unlike the RNA, orb protein is distributed along the entire cortex of the oocyte in stages S8-S10. Graded expression is also observed in nurse cells with the highest levels in the nurse cells closest to the oocyte.
GBrowse - Visual display of RNA-Seq signalsView Dmel\orb in GBrowse 2
Please Note FlyBase no longer curates genomic clone accessions so this list may not be complete
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
Source for identity of: orb CG10868
RNAi generated by PCR using primers directed to this gene causes a cell growth and viability phenotype when assayed in Kc167 and S2R+ cells.
All of the cells in the female germline cyst form synaptonemal complex in orb mutants.
Anterior localisation of RNA during oogenesis is very sensitive to microtubule inhibitors, taxol and other microtubule depolymerising agents. These results, together with colchicine treatment studies, demonstrate that microtubules are required for RNA transport to the oocyte.
Mutant analysis suggests that orb is required for A/P axis formation and D/V patterning.
280bp sequence from the orb 3' untranslated region is capable of reproducing orb mRNA complex localisation pattern during oogenesis. Multiple cis-acting elements appear to be required for proper targeting of orb mRNA.
Distribution of orb protein in wild type and mutant ovaries has been studies using antibodies.