Development Genes and Evolution

, Volume 211, Issue 2, pp 67–75 | Cite as

A search for Drosophila neural precursor genes identifies ran

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Original Article

Abstract.

The Drosophila ran gene has been isolated in a differential cDNA screen designed to identify genes that are dynamically expressed in embryonic neuroblasts. The guanine triphosphate (GTP)-binding Ran protein, a member of the Ras superfamily, has been shown to participate in a variety of transport related processes in other organisms. Drosophila ran codes for a 216 amino acid (aa) protein that shares 78% and 86% identity with the yeast and human Ran proteins, respectively. Database searches have identified a second Drosophila ran gene, ran-like. The predicted Ran-like protein shares 59% identity with its isoform. Embryo in situ mRNA localization of ran and ran-like expression reveals that both are maternally expressed; however zygotic ran expression is restricted to central nervous system (CNS) neuroblasts undergoing late lineage formation, while ran-like expression is detected in the developing trachea and salivary gland. To investigate the significance of ran-restricted CNS expression, we have targeted its misexpression to different temporal windows of CNS development. In addition, a dominant-negative mutant form of ran was targeted to the developing CNS and to the larval eye/antenna imaginal disc to assess the role of ran-dependent functions. Embryonic CNS misexpression of the mutant, but not wild-type, ran results in larval death. Neither wild-type nor mutant ran misexpression had any detectable effect on embryonic CNS lineage specification, nuclear transport of a number of CNS-specific transcription factors or axonal guidance. However, expression of the dominant-negative mutant ran in the developing eye/antenna disc did result in a severe adult eye phenotype marked by apoptosis of photoreceptor, cone and pigment cells.

Drosophila Ran Embryogenesis Ras superfamily 

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Copyright information

© Springer-Verlag 2001

Authors and Affiliations

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  1. 1.The Neurogenetics Unit, Laboratory of Neurochemistry, NINDS, NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
  2. 2.Laboratory of Molecular Biology, NINDS, NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA

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