Dr. Bradley W. Jones

Associate Professor
Department of Biology
The University of Mississippi

Contact:

Office: 122 Shoemaker Hall
E-mail: jonesbw@olemiss.edu
Telephone: (662) 915-1700


Research:

Molecular genetic mechanisms of nervous system development in Drosophila

We are interested in the development of the nervous system. A functional nervous system requires the correct specification and precise organization of a large number of neural cell types. These cell types include the neurons that transmit information and their glial support cells. Drosophila has proven to be an excellent model system for the study of mechanisms underlying neural development. In addition to its sophisticated classical and molecular genetic tools, much is known about the lineages, patterns, and identities of glia and neurons, and about the projections and pathways taken by axons in the developing CNS and PNS. Neurons and glia are arranged in a stereotypical pattern repeated in each segment. They are easily identified by position, and by a large array of markers. We take advantage of these features, using genetic and molecular approaches to uncover processes controlling neural cell fate specification and differentiation in Drosophila.

Drosophila embryos

Ventral views of Drosophila embryos several hours before hatching. Anterior is at the top.

A) The nerve tracks of the central nervous system are labeled with an antibody that recognizes an epitope in the axons of interneurons (brown).

B) The nuclei of glial cells are labeled by an antibody against Repo protein (black), a transcription factor required for the proper differentiation of glia.

Projects

Glial versus neuronal cell specification We are studying how neural stem cells acquire glial versus neuronal fates. A major player in this process is the glial cells missing gene (gcm), a master regulator of glial cell fate in Drosophila. gcm encodes a novel DNA-binding transcription factor that is required for the development of nearly all glia in Drosophila. In the presence of Gcm protein, neural cells develop into glia, while in its absence they become neurons. Several mammalian gcm homologs have been identified, and they have been shown to have conserved biochemical and regulatory properties. We have demonstrated that glial cell determination is controlled by the precise regulation of gcm expression and activity in neural progenitors. Because gcm is transiently expressed, gcm can only initiate glial cell differentiation. Downstream genes must accomplish glial differentiation and maintenance of glial cell fate. To understand how glial cell development is controlled, we aim to understand how gcm transcription is activated in different neural lineages, what factors regulate Gcm activity, and what are the downstream genes that carry out glial cell differentiation.

03-1
gcm is a master regulator of glial cell fate in Drosophila. Glial cells in the embryonic CNS as revealed by anti-Repo staining in four adjacent abdominal segmental neuromeres.

A) Wild type embryo.

B) gcmloss-of function embryo results in the absence of glial cell development.

C) Panneural expression of gcm causes nearly all CNS cells to develop into glial cells expressing Repo.

04-1

gcm functions as a binary genetic switch for glia vs. neurons. The dorsal bipolar dendrite (BD) lineage in the peripheral nervous system.

A) BD neuron (arrowhead) and glial support cell (arrow) in a wild type Drosophila embryo.

B) gcm loss-of-function mutant embryo.

C) gcm gain-of-function embryo, in which a transgenic construct drives ectopic gcmexpression in presumptive neurons.

We are currently pursuing these aims through the following projects:

  1. the molecular genetic characterization of cis-regulatory DNA elements controlling gcm transcription;
  2. the identification and characterization proteins that modulate Gcm activity;
  3. the molecular genetic characterization of cis-regulatory elements of the candidate gcm-target gene, repo; and,
  4. a systematic classical Drosophila mutagenesis screen for genes that modify the expression and pattern of Repo protein, a glial specific marker that is directly regulated by gcm. We are also pursuing reverse genetic approaches to identify new genes that potentially regulate glial and neuronal development.

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Education and Professional Experience:

B.A., Hamilton College, Clinton, NY. 1985 Major: Biology.

Research Technician, The National Institutes of Health, Bethesda, MD. 1986 Laboratory of Molecular Genetics, NINCDS. Dr. Robert Lazzarini, Supervisor. Expression patterns of mouse Hox genes.

Ph.D., Yale University, New Haven, CT. 1993 Department of Molecular, Cellular and Developmental Biology. Dr. William McGinnis, Advisor. Drosophila homeobox genes.

Postdoctoral Fellow, University of California, Berkeley, CA. 1993-1997 Department of Molecular and Cell Biology. Dr. Corey S. Goodman, Advisor. Neural development – glial cell differentiation in Drosophila.

Assistant Professor, New York University, New York, NY. 1998-2004 Molecular Neurobiology Program, Skirball Institute, NYU School of Medicine.

Assistant Professor, University of Mississippi, University, MS. 2004-present Department of Biology.
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Publications:

 

Hawkins, A.D., Thornton, C., Kennedy, A.J., Bu, K., Cizdziel, J., Jones, B. W., and Willett, K.L. (2015). Gill histopathologies following exposure to nanosilver or silver nitrate. Journal of Toxicology and Environmental Health, Part A. 78. 301-315.

Jones, B.W. (2014) Characterization of missense alleles of the glial cells missing gene of Drosophila. Genesis 52. 864-869.

Johnson, R.W., Wood, J.L. and Jones, B.W. (2012). Characterization of cis-regulatory elements controlling repo transcription in Drosophila melanogaster. Gene. 492, 167-176.

Lee, B.P. and Jones, B.W.(2005). Transcriptional regulation of the Drosophila glial gene repo. Mechanisms of Development, 122, 849-862.[abstract]

Jones, B.W.(2005). Transcriptional control of glial cell development in Drosophila. Developmental Biology 278, 265-273.[abstract]

Jones, B.W., Abeysekera, M., Galinska, J., and Jolicoeur, E.M.(2004). Transcriptional control of glial and blood cell development in Drosophila: cis-regulatory elements of glial cells missing. Developmental Biology 266, 374-387.[abstract]

Alfonso, T.B. and Jones, B.W.(2002). gcm2 promotes glial cell differentiation and is required with glial cells missing for macrophage development in Drosophila. Developmental Biology 248, 369-383.[abstract]

Jones, B.W.(2001). Glial cell development in the Drosophila embryo. BioEssays 23 (10), 877-887.[abstract]

Kim,J. *, Jones, B.W. *, Zock, C., Chen, Z., Wang, H., Goodman, C.S., and Anderson, D.J.(1998). Isolation and characterization of mammalian homologs of the Drosophila gene, glial cells missing. Proc. Natl. Acad. Sci. USA 95, 12364-12369.[abstract]  *These authors contributed equally to this work.

Jones, B.W., Fetter, R., Tear, G., and Goodman, C.S.(1995). glial cells missing: a genetic switch that controls glial versus neuronal fate. Cell 82: 1013-1023.[abstract]

Jones, B. and McGinnis, W.(1993) A new Drosophila homeobox gene, bsh, is expressed in a subset of brain cells during embryogenesis. Development 117: 793-806.[abstract]

Jones, B. and McGinnis, W.(1993) The regulation of empty spiracles by Abdominal-B mediates an abdominal segment identity function. Genes and Development 7: 229-240.[abstract]

Chadwick, R., Jones, B., Jack, T., and McGinnis W.(1990) Ectopic expression from the Deformed gene triggers a dominant defect in Drosophila adult head development. Developmental Biology 141, 130-140.[abstract]

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Courses:

Cell and Molecular Biology (BISC 440)
Principles of Developmental Biology (BISC 579)
Intro to Biological Sciences (BISC 160)

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Links:

  • FlyBase is a comprehensive database of the Drosophila genome.
  • The Bloomington Drosophila Stock Center collects, maintains and distributes Drosophila melanogaster strains for research.
  • The Berkeley Drosophila Genome Project is a consortium of the Drosophila Genome Center whose goals are to finish the sequence of the genome of Drosophila melanogaster and generate biological annotations of this sequence. In addition to genomic sequencing, the BDGP is 1) producing gene disruptions using P element-mediated mutagenesis on a scale unprecedented in metazoans; 2) characterizing the sequence and expression of cDNAs; and 3) developing informatics tools that support the experimental process, identify features of DNA sequence, and allow us to present up-to-date information about the annotated sequence to the research community.
  • The Interactive Fly is a web-based guide to Drosophila genes and their roles in development.
  • Trans-NIH Fly Initiative
  • The Atlas of Drosophila developmment features several groups of color illustrations that follow the main events of embryogenesis and post-embryonic development of Drosophila.
  • Drosophila Species Genomes. This service provides a preview of Drosophila genome data, with genome maps and BLAST sequence search, for these species. It includes prepublication, as well as published, Drosophila genomes from collaborating NGHRI-funded Genome Sequencing Centers .
  • FlyView is an image database on Drosophila development and genetics, especially on expression patterns of genes (enhancer trap lines, cloned genes).
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