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Genetics. May 1999; 152(1): 299–305.
PMCID: PMC1460606

Tramtrack69 is positively and autonomously required for Drosophila photoreceptor development.


Cell-fate specification and cellular differentiation are tightly controlled by both positive and negative transcriptional factors during development. The Drosophila BTB/POZ (Bric-a-brac Tramtrack Broad complex/Pox virus and Zinc finger) domain-containing Tramtrack (Ttk) proteins have been previously shown to be transcriptional repressors and inhibitors of the neuronal fate of cells such as photoreceptors. Here we provide evidence that one of the Ttk proteins, Ttk69, also plays a positive and autonomous role in promoting or maintaining differentiation of photoreceptor neurons at the late stages of Drosophila eye development. Consistent with this notion, the Ttk69 protein, but not Ttk88, is expressed in all photoreceptor cells during pupal stage. Thus, Ttk69 appears to play a dual function by serving negative and positive regulatory roles at different stages of photoreceptor development.

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Selected References

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  • Badenhorst P, Harrison S, Travers A. End of the line? Tramtrack and cell fate determination in Drosophila. Genes Cells. 1996 Aug;1(8):707–716. [PubMed]
  • Brown JL, Wu C. Repression of Drosophila pair-rule segmentation genes by ectopic expression of tramtrack. Development. 1993 Jan;117(1):45–58. [PubMed]
  • Brown JL, Sonoda S, Ueda H, Scott MP, Wu C. Repression of the Drosophila fushi tarazu (ftz) segmentation gene. EMBO J. 1991 Mar;10(3):665–674. [PMC free article] [PubMed]
  • Li S, Li Y, Carthew RW, Lai ZC. Photoreceptor cell differentiation requires regulated proteolysis of the transcriptional repressor Tramtrack. Cell. 1997 Aug 8;90(3):469–478. [PubMed]
  • Burke R, Basler K. Hedgehog signaling in Drosophila eye and limb development - conserved machinery, divergent roles? Curr Opin Neurobiol. 1997 Feb;7(1):55–61. [PubMed]
  • Cutforth T, Gaul U. The genetics of visual system development in Drosophila: specification, connectivity and asymmetry. Curr Opin Neurobiol. 1997 Feb;7(1):48–54. [PubMed]
  • Read D, Manley JL. Alternatively spliced transcripts of the Drosophila tramtrack gene encode zinc finger proteins with distinct DNA binding specificities. EMBO J. 1992 Mar;11(3):1035–1044. [PMC free article] [PubMed]
  • Read D, Levine M, Manley JL. Ectopic expression of the Drosophila tramtrack gene results in multiple embryonic defects, including repression of even-skipped and fushi tarazu. Mech Dev. 1992 Sep;38(3):183–195. [PubMed]
  • Salzberg A, D'Evelyn D, Schulze KL, Lee JK, Strumpf D, Tsai L, Bellen HJ. Mutations affecting the pattern of the PNS in Drosophila reveal novel aspects of neuronal development. Neuron. 1994 Aug;13(2):269–287. [PubMed]
  • Tang AH, Neufeld TP, Kwan E, Rubin GM. PHYL acts to down-regulate TTK88, a transcriptional repressor of neuronal cell fates, by a SINA-dependent mechanism. Cell. 1997 Aug 8;90(3):459–467. [PubMed]
  • Giesen K, Hummel T, Stollewerk A, Harrison S, Travers A, Klämbt C. Glial development in the Drosophila CNS requires concomitant activation of glial and repression of neuronal differentiation genes. Development. 1997 Jun;124(12):2307–2316. [PubMed]
  • Treisman JE, Heberlein U. Eye development in Drosophila: formation of the eye field and control of differentiation. Curr Top Dev Biol. 1998;39:119–158. [PubMed]
  • Guo M, Bier E, Jan LY, Jan YN. tramtrack acts downstream of numb to specify distinct daughter cell fates during asymmetric cell divisions in the Drosophila PNS. Neuron. 1995 May;14(5):913–925. [PubMed]
  • Treisman JE, Luk A, Rubin GM, Heberlein U. eyelid antagonizes wingless signaling during Drosophila development and has homology to the Bright family of DNA-binding proteins. Genes Dev. 1997 Aug 1;11(15):1949–1962. [PMC free article] [PubMed]
  • Harrison SD, Travers AA. The tramtrack gene encodes a Drosophila finger protein that interacts with the ftz transcriptional regulatory region and shows a novel embryonic expression pattern. EMBO J. 1990 Jan;9(1):207–216. [PMC free article] [PubMed]
  • Heberlein U, Moses K. Mechanisms of Drosophila retinal morphogenesis: the virtues of being progressive. Cell. 1995 Jun 30;81(7):987–990. [PubMed]
  • Xiong WC, Montell C. tramtrack is a transcriptional repressor required for cell fate determination in the Drosophila eye. Genes Dev. 1993 Jun;7(6):1085–1096. [PubMed]
  • Klämbt C. Drosophila development: a receptor for ommatidial recruitment. Curr Biol. 1997 Mar 1;7(3):R132–R135. [PubMed]
  • Kumar J, Moses K. Transcription factors in eye development: a gorgeous mosaic? Genes Dev. 1997 Aug 15;11(16):2023–2028. [PubMed]
  • Xu T, Rubin GM. Analysis of genetic mosaics in developing and adult Drosophila tissues. Development. 1993 Apr;117(4):1223–1237. [PubMed]
  • Kumar JP, Ready DF. Rhodopsin plays an essential structural role in Drosophila photoreceptor development. Development. 1995 Dec;121(12):4359–4370. [PubMed]
  • Lai ZC, Rubin GM. Negative control of photoreceptor development in Drosophila by the product of the yan gene, an ETS domain protein. Cell. 1992 Aug 21;70(4):609–620. [PubMed]
  • Lai ZC, Harrison SD, Karim F, Li Y, Rubin GM. Loss of tramtrack gene activity results in ectopic R7 cell formation, even in a sina mutant background. Proc Natl Acad Sci U S A. 1996 May 14;93(10):5025–5030. [PMC free article] [PubMed]

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