Gene Symbol: orb
Description: oo18 RNA-binding protein
Alias: 151666_s_at, CG10868, Dmel\CG10868, ORB, Oo18, Orb, Orb1, fs(3)00107, oo18, oo18 RNA-binding protein, CG10868-PA, CG10868-PB, CG10868-PC, CG10868-PD, CG10868-PE, CG10868-PF, CG10868-PG, ORB, Oo18 RNA-binding protein, oo18 RNA binding, oo18 RNA binding protein, orb-PA, orb-PB, orb-PC, orb-PD, orb-PE, orb-PF, orb-PG
Species: fruit fly
Products:     orb

Top Publications

  1. Narbonne K, Besse F, Brissard Zahraoui J, Pret A, Busson D. polyhomeotic is required for somatic cell proliferation and differentiation during ovarian follicle formation in Drosophila. Development. 2004;131:1389-400 pubmed
    ..Our results provide a new model system, the Drosophila ovary, in which the function of Pc-G genes, distinct from that of control of homeotic gene expression, can be explored. ..
  2. Bécam I, Tanentzapf G, Lepesant J, Brown N, Huynh J. Integrin-independent repression of cadherin transcription by talin during axis formation in Drosophila. Nat Cell Biol. 2005;7:510-6 pubmed
    ..Surprisingly, this function of talin is independent of integrins. These results uncover a new role for talin in regulating cadherin-mediated cell adhesion. ..
  3. Malmanche N, Owen S, Gegick S, Steffensen S, Tomkiel J, Sunkel C. Drosophila BubR1 is essential for meiotic sister-chromatid cohesion and maintenance of synaptonemal complex. Curr Biol. 2007;17:1489-97 pubmed
    ..Our results demonstrate that BubR1 is essential to maintain sister-chromatid cohesion during meiotic progression in both sexes and for normal maintenance of SC in females...
  4. Bogard N, Lan L, Xu J, Cohen R. Rab11 maintains connections between germline stem cells and niche cells in the Drosophila ovary. Development. 2007;134:3413-8 pubmed
    ..These studies bring into focus the important role of membrane trafficking in stem cell biology. ..
  5. Styhler S, Nakamura A, Swan A, Suter B, Lasko P. vasa is required for GURKEN accumulation in the oocyte, and is involved in oocyte differentiation and germline cyst development. Development. 1998;125:1569-78 pubmed
    ..vasa-null oocytes fail to efficiently accumulate many localized RNAs, such as Bicaudal-D, orb, oskar, and nanos, but still accumulate gurken RNA...
  6. Findley S, Tamanaha M, Clegg N, Ruohola Baker H. Maelstrom, a Drosophila spindle-class gene, encodes a protein that colocalizes with Vasa and RDE1/AGO1 homolog, Aubergine, in nuage. Development. 2003;130:859-71 pubmed
    ..Furthermore, maelstrom mutant ovaries show mislocalization of two proteins involved in the microRNA and/or RNAi pathways, Dicer and Argonaute2, suggesting a potential connection between nuage and the microRNA-pathway. ..
  7. Lantz V, Chang J, Horabin J, Bopp D, Schedl P. The Drosophila orb RNA-binding protein is required for the formation of the egg chamber and establishment of polarity. Genes Dev. 1994;8:598-613 pubmed
    The orb gene of Drosophila encodes sex-specific germ-line proteins that contain two RRM-type RNA-binding domains. Here we report the distribution of Orb protein in wild-type, tumorous, and orb mutant ovaries...
  8. Deng W, Lin H. Spectrosomes and fusomes anchor mitotic spindles during asymmetric germ cell divisions and facilitate the formation of a polarized microtubule array for oocyte specification in Drosophila. Dev Biol. 1997;189:79-94 pubmed
    ..polarized microtubule networks do not form, the dynamics of cytoplasmic dynein is disrupted, and oskar and orb RNAs fail to be transported to the future oocyte...
  9. Assa Kunik E, Torres I, Schejter E, Johnston D, Shilo B. Drosophila follicle cells are patterned by multiple levels of Notch signaling and antagonism between the Notch and JAK/STAT pathways. Development. 2007;134:1161-9 pubmed

More Information


  1. Benoit P, Papin C, Kwak J, Wickens M, Simonelig M. PAP- and GLD-2-type poly(A) polymerases are required sequentially in cytoplasmic polyadenylation and oogenesis in Drosophila. Development. 2008;135:1969-79 pubmed publisher
    ..In Drosophila, canonical PAP is involved in cytoplasmic polyadenylation with Orb, the Drosophila CPEB, during mid-oogenesis. We show that the female germline GLD-2 is encoded by wispy...
  2. Christerson L, McKearin D. orb is required for anteroposterior and dorsoventral patterning during Drosophila oogenesis. Genes Dev. 1994;8:614-28 pubmed
    We describe mutations in the orb gene, identified previously as an ovarian-specific member of a large family of RNA-binding proteins...
  3. Fichelson P, Moch C, Ivanovitch K, Martin C, Sidor C, Lepesant J, et al. Live-imaging of single stem cells within their niche reveals that a U3snoRNP component segregates asymmetrically and is required for self-renewal in Drosophila. Nat Cell Biol. 2009;11:685-93 pubmed publisher
    ..In the absence of Wcd, NSCs became smaller and produced fewer neurons. Our results show that regulation of ribosome synthesis is a crucial parameter for stem cell maintenance and function. ..
  4. Sherizen D, Jang J, Bhagat R, Kato N, McKim K. Meiotic recombination in Drosophila females depends on chromosome continuity between genetically defined boundaries. Genetics. 2005;169:767-81 pubmed
    ..These sites are not required for homolog pairing. Instead, the initiation of meiotic recombination requires continuity of the meiotic chromosome structure within each of these domains. ..
  5. Reveal B, Yan N, Snee M, Pai C, Gim Y, Macdonald P. BREs mediate both repression and activation of oskar mRNA translation and act in trans. Dev Cell. 2010;18:496-502 pubmed publisher
    ..Regulation in trans is likely enabled by assembly of oskar transcripts in cytoplasmic RNPs. Concentration of transcripts in such RNPs is common, and trans regulation of mRNAs may therefore be widespread...
  6. Kim Ha J, Kerr K, Macdonald P. Translational regulation of oskar mRNA by bruno, an ovarian RNA-binding protein, is essential. Cell. 1995;81:403-12 pubmed
    ..Addition of BREs to a heterologous mRNA renders it sensitive to translational repression in the ovary. ..
  7. Narbonne Reveau K, Lilly M. The Cyclin-dependent kinase inhibitor Dacapo promotes genomic stability during premeiotic S phase. Mol Biol Cell. 2009;20:1960-9 pubmed publisher
    ..Finally, we report that dap(-/-) ovarian cysts frequently undergo an extramitotic division before meiotic entry, indicating that Dap influences the timing of the mitotic/meiotic transition. ..
  8. Ivshina M, Lasko P, Richter J. Cytoplasmic polyadenylation element binding proteins in development, health, and disease. Annu Rev Cell Dev Biol. 2014;30:393-415 pubmed publisher
    ..In Drosophila, the CPEB proteins Orb and Orb2 play key roles in oogenesis and in neuronal function, as do related proteins in Caenorhabditis elegans and ..
  9. Deng W, Schneider M, Frock R, Castillejo Lopez C, Gaman E, Baumgartner S, et al. Dystroglycan is required for polarizing the epithelial cells and the oocyte in Drosophila. Development. 2003;130:173-84 pubmed
    ..These data suggest that the primary function of Dystroglycan in oogenesis is to organize cellular polarity; and this study sets the stage for analyzing the Dystroglycan complex by using the power of Drosophila molecular genetics. ..
  10. Nakamura A, Amikura R, Hanyu K, Kobayashi S. Me31B silences translation of oocyte-localizing RNAs through the formation of cytoplasmic RNP complex during Drosophila oogenesis. Development. 2001;128:3233-42 pubmed
    ..These results suggest that Me31B mediates translational silencing of RNAs during their transport to the oocyte. Our data provide evidence that RNA transport and translational control are linked through the assembly of RNP complex. ..
  11. Huynh J, Petronczki M, Knoblich J, St Johnston D. Bazooka and PAR-6 are required with PAR-1 for the maintenance of oocyte fate in Drosophila. Curr Biol. 2001;11:901-6 pubmed
    ..Furthermore, oocyte-specific factors, such as Orb protein and the centrosomes, still localize to one cell but fail to move from the anterior to the posterior cortex...
  12. Iida T, Lilly M. missing oocyte encodes a highly conserved nuclear protein required for the maintenance of the meiotic cycle and oocyte identity in Drosophila. Development. 2004;131:1029-39 pubmed
    ..Our data strongly suggest that the product of the missing oocyte gene acts in the oocyte nucleus to facilitate the execution of the unique cell cycle and developmental programs that produce the mature haploid gamete. ..
  13. Pokrywka N, Stephenson E. Microtubules are a general component of mRNA localization systems in Drosophila oocytes. Dev Biol. 1995;167:363-70 pubmed
    ..For example, Bicaudal-D, fs (1) K10, and orb RNAs are transiently localized at the anterior oocyte margin in mid oogenesis, and oskar RNA is localized at the ..
  14. Page S, Hawley R. c(3)G encodes a Drosophila synaptonemal complex protein. Genes Dev. 2001;15:3130-43 pubmed
    ..Moreover, the observation of interference among the residual exchanges in these mutant oocytes implies that complete SC formation is not required for crossover interference in Drosophila. ..
  15. Jang J, Sherizen D, Bhagat R, Manheim E, McKim K. Relationship of DNA double-strand breaks to synapsis in Drosophila. J Cell Sci. 2003;116:3069-77 pubmed
    ..There may also be an interaction between the recruitment of repair proteins and phosphorylation. ..
  16. Huynh J, St Johnston D. The role of BicD, Egl, Orb and the microtubules in the restriction of meiosis to the Drosophila oocyte. Development. 2000;127:2785-94 pubmed
    ..of the SC: none of the cells in the cyst form SC in BicD null mutants, whereas all of the cells do in egl and orb mutants...
  17. Navarro C, Puthalakath H, Adams J, Strasser A, Lehmann R. Egalitarian binds dynein light chain to establish oocyte polarity and maintain oocyte fate. Nat Cell Biol. 2004;6:427-35 pubmed
    ..Our data provide a direct link between a molecule necessary for oocyte specification and the microtubule motor complex, and supports the hypothesis that microtubule-mediated transport is important for preserving oocyte fate. ..
  18. Gervais L, Claret S, Januschke J, Roth S, Guichet A. PIP5K-dependent production of PIP2 sustains microtubule organization to establish polarized transport in the Drosophila oocyte. Development. 2008;135:3829-38 pubmed publisher
  19. Deshpande G, Samuels M, Schedl P. Sex-lethal interacts with splicing factors in vitro and in vivo. Mol Cell Biol. 1996;16:5036-47 pubmed
    ..This model helps explain how the Sxl protein is able to promote the sex-specific splicing of Sxl transcripts, utilizing target sequences that are distant from the regulated splice sites. ..
  20. Castagnetti S, Ephrussi A. Orb and a long poly(A) tail are required for efficient oskar translation at the posterior pole of the Drosophila oocyte. Development. 2003;130:835-43 pubmed
    ..of Oskar activity requires the Drosophila homolog of Cytoplasmic Polyadenylation Element Binding protein (CPEB), Orb. As posterior localization of oskar mRNA is an essential prerequisite for its translation, it was critical to ..
  21. Shcherbata H, Yatsenko A, Patterson L, Sood V, Nudel U, Yaffe D, et al. Dissecting muscle and neuronal disorders in a Drosophila model of muscular dystrophy. EMBO J. 2007;26:481-93 pubmed
    ..Importantly, we now report that Dg interacts with insulin receptor and Nck/Dock SH2/SH3-adaptor molecule in photoreceptor path-finding. This is the first demonstration of a genetic interaction between Dg and InR. ..
  22. Lantz V, Schedl P. Multiple cis-acting targeting sequences are required for orb mRNA localization during Drosophila oogenesis. Mol Cell Biol. 1994;14:2235-42 pubmed
    ..In many developmental systems, this is accomplished by localization of mRNAs. The germ line-specific Drosophila orb gene plays a critical role in defining both axes of the developing oocyte, and its mRNA is localized in a complex ..
  23. González Reyes A, St Johnston D. The Drosophila AP axis is polarised by the cadherin-mediated positioning of the oocyte. Development. 1998;125:3635-44 pubmed
    ..The Drosophila anterior-posterior axis therefore becomes polarised by an unusual cadherin-mediated adhesion between a germ cell and mesodermal follicle cells. ..
  24. Cox D, Seyfried S, Jan L, Jan Y. Bazooka and atypical protein kinase C are required to regulate oocyte differentiation in the Drosophila ovary. Proc Natl Acad Sci U S A. 2001;98:14475-80 pubmed
  25. Brendza R, Serbus L, Duffy J, Saxton W. A function for kinesin I in the posterior transport of oskar mRNA and Staufen protein. Science. 2000;289:2120-2 pubmed
    ..Thus, a complex containing oskar mRNA and Staufen may be transported along microtubules to the posterior pole by kinesin I. ..
  26. Cox D, Lu B, Sun T, Williams L, Jan Y. Drosophila par-1 is required for oocyte differentiation and microtubule organization. Curr Biol. 2001;11:75-87 pubmed
    ..In both cases, par-1 appears to exert its effects through the regulation of microtubule dynamics and/or stability, and this finding is consistent with the defined role of the mammalian PAR-1 homologs. ..
  27. Lantz V, Ambrosio L, Schedl P. The Drosophila orb gene is predicted to encode sex-specific germline RNA-binding proteins and has localized transcripts in ovaries and early embryos. Development. 1992;115:75-88 pubmed
    We report the identification of a new gene, orb, which appears to be expressed only in the germline and encodes ovarian- and testis-specific transcripts...
  28. Benoit B, Mitou G, Chartier A, Temme C, Zaessinger S, Wahle E, et al. An essential cytoplasmic function for the nuclear poly(A) binding protein, PABP2, in poly(A) tail length control and early development in Drosophila. Dev Cell. 2005;9:511-22 pubmed
    ..Both Cyclin B protein levels and embryonic development depend upon this regulation. These results identify a regulator of maternal mRNA poly(A) tail length and highlight the importance of this mode of translational control. ..
  29. Schupbach T, Roth S. Dorsoventral patterning in Drosophila oogenesis. Curr Opin Genet Dev. 1994;4:502-7 pubmed
    ..This localized signal from the oocyte to the follicle cells appears to initiate a cascade of events leading to dorsal follicle cell differentiation, and delimiting and orienting the future dorsoventral axis of the embryo. ..
  30. Hafer N, Xu S, Bhat K, Schedl P. The Drosophila CPEB protein Orb2 has a novel expression pattern and is important for asymmetric cell division and nervous system function. Genetics. 2011;189:907-21 pubmed publisher
    ..Drosophila has two CPEB family members. One of these, orb, plays a key role in the establishment of polarity axes in the developing egg and early embryo, but has no known ..
  31. Torres I, Lopez Schier H, St Johnston D. A Notch/Delta-dependent relay mechanism establishes anterior-posterior polarity in Drosophila. Dev Cell. 2003;5:547-58 pubmed
    ..The anterior-posterior axis is therefore established by a relay mechanism, which propagates polarity from one cyst to the next. ..
  32. Staeva Vieira E, Yoo S, Lehmann R. An essential role of DmRad51/SpnA in DNA repair and meiotic checkpoint control. EMBO J. 2003;22:5863-74 pubmed
    ..We therefore propose that under normal conditions a second, Rad51-independent, repair pathway prevents the lethal effects of DNA damage. ..
  33. Bolivar J, Huynh J, Lopez Schier H, Gonzalez C, St Johnston D, González Reyes A. Centrosome migration into the Drosophila oocyte is independent of BicD and egl, and of the organisation of the microtubule cytoskeleton. Development. 2001;128:1889-97 pubmed
    ..Thus, centrosome migration is independent of the organisation of the microtubule cytoskeleton, and seems to depend instead on the polarity of the fusome. ..
  34. Yatsenko A, Gray E, Shcherbata H, Patterson L, Sood V, Kucherenko M, et al. A putative Src homology 3 domain binding motif but not the C-terminal dystrophin WW domain binding motif is required for dystroglycan function in cellular polarity in Drosophila. J Biol Chem. 2007;282:15159-69 pubmed
    ..This suggests that an SH3-containing protein, which has yet to be identified, functionally interacts with Dg. ..
  35. Spradling A. Germline cysts: communes that work. Cell. 1993;72:649-51 pubmed
  36. Roth S, Schupbach T. The relationship between ovarian and embryonic dorsoventral patterning in Drosophila. Development. 1994;120:2245-57 pubmed
    ..A change in distribution of the germ-line signal as caused by fs(1)K10, squid and orb mutations leads to a shift in the orientation of the embryonic dorsoventral axis relative to the anterior-posterior ..
  37. Costa A, Wang Y, Dockendorff T, Erdjument Bromage H, Tempst P, Schedl P, et al. The Drosophila fragile X protein functions as a negative regulator in the orb autoregulatory pathway. Dev Cell. 2005;8:331-42 pubmed
    ..In Drosophila, Orb is responsible for mediating the translational activation of mRNAs localized within the developing oocyte...
  38. Chang J, Tan L, Schedl P. The Drosophila CPEB homolog, orb, is required for oskar protein expression in oocytes. Dev Biol. 1999;215:91-106 pubmed
    ..Here we have investigated the role of the Drosophila CPEB homolog, the orb gene, in the osk mRNA localization pathway...
  39. McCaffrey R, St Johnston D, González Reyes A. Drosophila mus301/spindle-C encodes a helicase with an essential role in double-strand DNA break repair and meiotic progression. Genetics. 2006;174:1273-85 pubmed
    ..However, neither mei-W68 nor mei-41 rescue the defects in oocyte specification of mus301 mutants, suggesting that this helicase has another function in oocyte selection that is independent from its role in meiotic recombination. ..
  40. Capri M, Santoni M, Thomas Delaage M, Ait Ahmed O. Implication of a 5' coding sequence in targeting maternal mRNA to the Drosophila oocyte. Mech Dev. 1997;68:91-100 pubmed
    ..We show that the 5' coding sequence is necessary for the early accumulation of yem-alpha RNA in the oocyte and for its localization pattern during oogenesis. ..
  41. Besse F, López de Quinto S, Marchand V, Trucco A, Ephrussi A. Drosophila PTB promotes formation of high-order RNP particles and represses oskar translation. Genes Dev. 2009;23:195-207 pubmed publisher
    ..Thus, PTB is a key structural component of oskar RNP complexes that dually controls formation of high-order RNP particles and translational silencing. ..
  42. Cox R, Spradling A. A Balbiani body and the fusome mediate mitochondrial inheritance during Drosophila oogenesis. Development. 2003;130:1579-90 pubmed
    ..Our findings reveal new similarities between oogenesis in Drosophila and vertebrates, and support our hypothesis that developing oocytes contain specific mechanisms to ensure that germ plasm is endowed with highly functional organelles. ..
  43. Wong L, Schedl P. Cup blocks the precocious activation of the orb autoregulatory loop. PLoS ONE. 2011;6:e28261 pubmed publisher
    ..In the Drosophila ovary, the germline-specific Orb protein mediates the translational activation of a variety of mRNAs localized in the oocyte...
  44. Liu H, Jang J, Kato N, McKim K. mei-P22 encodes a chromosome-associated protein required for the initiation of meiotic recombination in Drosophila melanogaster. Genetics. 2002;162:245-58 pubmed
    ..We propose that MEI-P22 interacts with meiosis-specific chromosome proteins to facilitate DSB creation by MEI-W68. ..
  45. Peifer M, Orsulic S, Sweeton D, Wieschaus E. A role for the Drosophila segment polarity gene armadillo in cell adhesion and cytoskeletal integrity during oogenesis. Development. 1993;118:1191-207 pubmed
    ..The implications of these results for the role of adhesive junctions during development are discussed. ..
  46. Huynh J, Shulman J, Benton R, St Johnston D. PAR-1 is required for the maintenance of oocyte fate in Drosophila. Development. 2001;128:1201-9 pubmed
    ..oocyte determination are delayed, three markers for oocyte identity, the synaptonemal complex, the centrosomes and Orb protein, still become restricted to one cell in mutant clones...
  47. Bullock S, Ish Horowicz D. Conserved signals and machinery for RNA transport in Drosophila oogenesis and embryogenesis. Nature. 2001;414:611-6 pubmed
    ..We propose that Egl and BicD are core components of a selective dynein motor complex that drives transcript localization in a variety of tissues. ..
  48. Weil T, Parton R, Herpers B, Soetaert J, Veenendaal T, Xanthakis D, et al. Drosophila patterning is established by differential association of mRNAs with P bodies. Nat Cell Biol. 2012;14:1305-13 pubmed publisher
    ..that become docked and translated at the periphery of P bodies, where we show that the translational activator Oo18 RNA-binding protein (Orb, a homologue of CEPB) and the anchoring factor Squid (Sqd) are also enriched...
  49. Tastan O, Maines J, Li Y, McKearin D, Buszczak M. Drosophila ataxin 2-binding protein 1 marks an intermediate step in the molecular differentiation of female germline cysts. Development. 2010;137:3167-76 pubmed publisher
    ..4-, 8- and 16-cell cysts, bridging the expression of the early differentiation factor Bam with late markers such as Orb, Rbp9 and Bruno encoded by arrest...
  50. Snee M, Macdonald P. Dynamic organization and plasticity of sponge bodies. Dev Dyn. 2009;238:918-30 pubmed publisher
    ..Based on these and other results we propose a model for the relationship between P bodies and the various cytoplasmic bodies containing P body proteins in the Drosophila ovary. ..
  51. Tan L, Chang J, Costa A, Schedl P. An autoregulatory feedback loop directs the localized expression of the Drosophila CPEB protein Orb in the developing oocyte. Development. 2001;128:1159-69 pubmed
    The RRM-type RNA binding protein Orb plays a central role in the establishment of polarity in the Drosophila egg and embryo...
  52. Joyce E, McKim K. Drosophila PCH2 is required for a pachytene checkpoint that monitors double-strand-break-independent events leading to meiotic crossover formation. Genetics. 2009;181:39-51 pubmed publisher
    ..Interestingly, PCH2-dependent delays in prophase may allow additional crossovers to form. ..
  53. Chang J, Tan L, Wolf M, Schedl P. Functioning of the Drosophila orb gene in gurken mRNA localization and translation. Development. 2001;128:3169-77 pubmed
    The orb gene encodes an RNA recognition motif (RRM)-type RNA-binding protein that is a member of the cytoplasmic polyadenylation element binding protein (CPEB) family of translational regulators...
  54. Jeffress J, Page S, Royer S, Belden E, Blumenstiel J, Anderson L, et al. The formation of the central element of the synaptonemal complex may occur by multiple mechanisms: the roles of the N- and C-terminal domains of the Drosophila C(3)G protein in mediating synapsis and recombination. Genetics. 2007;177:2445-56 pubmed
  55. McGregor J, Xi R, Harrison D. JAK signaling is somatically required for follicle cell differentiation in Drosophila. Development. 2002;129:705-17 pubmed
    ..Consistent with these data is a model in which Notch signaling determines a pool of cells to be competent to adopt stalk or polar fate, while JAK signaling assigns specific identity within that competent pool. ..
  56. Zappavigna V, Piccioni F, Villaescusa J, Verrotti A. Cup is a nucleocytoplasmic shuttling protein that interacts with the eukaryotic translation initiation factor 4E to modulate Drosophila ovary development. Proc Natl Acad Sci U S A. 2004;101:14800-5 pubmed
    ..Our results reveal a crucial role for the Cup-eIF4E complex in ovary-specific developmental programs. ..
  57. Navarro C, Bullock S, Lehmann R. Altered dynein-dependent transport in piRNA pathway mutants. Proc Natl Acad Sci U S A. 2009;106:9691-6 pubmed publisher
    ..We propose that aggregate formation is a cellular response to protect germ cells from DNA damage caused by elevated retrotransposon expression. ..
  58. González Reyes A, Elliott H, St Johnston D. Polarization of both major body axes in Drosophila by gurken-torpedo signalling. Nature. 1995;375:654-8 pubmed
    ..As the gurken-torpedo/DER pathway also establishes dorsoventral polarity later in oogenesis, Drosophila uses the same germline to soma signalling pathway to determine both embryonic axes. ..
  59. Wong L, Costa A, McLeod I, Sarkeshik A, Yates J, Kyin S, et al. The functioning of the Drosophila CPEB protein Orb is regulated by phosphorylation and requires casein kinase 2 activity. PLoS ONE. 2011;6:e24355 pubmed publisher
    The Orb CPEB protein regulates translation of localized mRNAs in Drosophila ovaries...
  60. Gong W, McKim K, Hawley R. All paired up with no place to go: pairing, synapsis, and DSB formation in a balancer heterozygote. PLoS Genet. 2005;1:e67 pubmed
  61. Morris J, Navarro C, Lehmann R. Identification and analysis of mutations in bob, Doa and eight new genes required for oocyte specification and development in Drosophila melanogaster. Genetics. 2003;164:1435-46 pubmed
    ..We identified alleles of oo18 RNA binding protein (orb) and Darkener of apricot (Doa), which had previously been shown to exhibit oogenesis defects...