Mailing Address:

University of Chicago

5841 S. Maryland Ave.,

MC 1028 Room N-101

Chicago, IL 60637

Lab TEL (773) 702-6274

FAX (773) 702-0271

email: cjaramil@midway.uchicago.edu

Abstract of Thesis

University of Chicago

June 2003

Evolution of the Insect Segmentation Hierarchy: Comparative Analysis of the Patterning Process in Long and Short Germ Insects

Knowledge of how insects generate body segments is based on our understanding of the Drosophila segmentation mechanisms. The hallmarks of this genetic network are efficient generation of segments along the anterior-posterior axis, pre-patterning of those segments in a syncytium before gastrulation, and hierarchical and combinatorial regulatory interactions which generate the reiterated pattern. We have begun to address whether these same systems are being utilized in other insects, specifically, the short germ grasshopper, Schistocerca americana, a species that forms segments after gastrulation in a cellular environment.

The work presented here demonstrates that despite dramatic differences observed between Drosophila and Schistocerca segmentation, similarities in the molecular patterning systems underlying this developmental process are evident. First, I show that pby1, a Schistocerca homologue of the Drosophila pair-rule gene prd is expressed in a two-segment periodicity. In Drosophila, prd is thought to be involved in the transition from pair-rule function to segment polarity function and I show that this mechanism is also apparently conserved. In addition, I show temporal differences between the inititation of segment polarity genes in Schistocerca and Drosophila. Finally, I suggest possibilities for the use of wingless in the initiation of other segment polarity genes and I also suggest that the expression patterns of previously studied Schistocerca pair-rule homologues should be reconsidered.

Education:

September 1996 - 2003

University of Chicago, Committee on Developmental Biology
Advisor: Dr. Nipam H. Patel

August 1988 - May 1996

University of North Texas, Department of Biological Sciences
Advisor: Dr. Jannon Fuchs

Awards and Fellowships:1994-1996

Ronald E. McNair Post-Baccalaureate Achievement Program

1996-present

APA-Minority Fellowship Program in Neuroscience,

Research Experience and Training:1993-1994

Trimethylsilyacetylene as a building block for the synthesis of the anthelmintic bismacrolide clonostachydiol. Dr. Roderick Bates, Ph.d., Assistant Professor. University of North Texas, Department of Chemistry.

1994-1996

The effects of neural input on the expression of mRNA encoding the alpha3 subunit of the nicotinic acetylcholine receptor in the developing rat visual cortex. Dr. Jannon Fuchs, Ph.D., Associate Professor. University of North Texas, Department of Biological Sciences.

June 15- July 12, 1996

Summer Program in Neuroscience, Ethics, and Survival
APA-MFP, Association of Neuroscience Department and Programs
Marine Biological Laboratory, Woods Hole, MA.

Publications/Presentations:

Davis, G.K., Jaramillo, C.A. and Patel, N.H. (2001). Pax group III genes and the evolution of pair rule pattern. Development, 128, 3445-3458.

"Trimethylsilyacetylene as a Building Block for Natural Product Synthesis," R.W. Bates, C. Jaramillo, S. Lee, T. Maiti, 208th American Chemical Society National Meeting and exposition Poster Presentation, Washington, DC, August 21-25, 1994.

"Effects of Neural Input on alpha3 Nicotinic Acetylcholine receptor mRNA in the Developing Rat Visual Cortex," C. Jaramillo, T.A. Austin, J.L. Fuchs, 3rd Annual National Ronald E. McNair Student conference Presentation of Student Research, Lake Lawn Lodge, Delavan, Wisconsin, November 11-13, 1994.

"The Effects of Surgical Isolation on the Expression of mRNA Encoding the alpha3 Subunit of the Nicotinic Acetylcholine Receptor in the Developing Rat Visual Cortex." C.A. Jaramillo, T.A. Austin, J. L. Fuchs. APA/MFP Summer Program in Neuroscience, Ethics, and Survival Research Conference, Marine Biological Laboratory, Woods Hole, Massachusetts, July 12, 1996.

"Expression of Pair-Berry and the Evolution of Segmentation." Davis, G.K., Jaramillo, C.A., and Patel, N.H., Annual Meeting of the Society for Integrative and Comparative Biology, January 4-8, 2000; to be published in the Abstract Edition of American Zoologist.

Research Interests:

I am interested in examining the origin and evolution of novel gene functions that play a role in animal development. One way that novel gene functions can arise is through gene duplication and subsequent regulatory divergence, leading to the emergence of regulatory gene clusters and networks. In particular, I am studying the evolution of three genes, paired (prd), gooseberry (gsb), and gooseberry-neuro (gsb-n), which make up the Paired group III (PgIII) genes of Drosophila melanogaster. The PgIII genes share strong sequence and structural similarities and contain two DNA binding motifs, a paired domain and a homeodomain. Various lines of evidence suggest that the Drosophila PgIII gene set was generated by two duplication events during insect evolution, the first generating prd and the precursor to gsb and gsb-n, and the second generating gsb and gsb-n from this precursor.

Genetic rescue experiments in Drosophila clearly indicate that it is changes in cis-regulatory sequences as opposed to changes in gene sequence which have lead to the distinct functions of the PgIII genes of Drosophila. How did these regulatory sequence changes occur, and what were the ancestral functions of the PgIII gene precursors? In order to address these questions, I will be characterizing the function and regulation of PgIII genes in other phylogenetically more primitive insects.

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