Tube formation is a ubiquitous process required to sustain life in multicellular organisms. Tubular organs include the lungs, vasculature, digestive and excretory systems, as well as secretory organs such as the pancreas, salivary, prostrate, and mammary glands. Moreover, the heart and central nervous system begin as tubular organs. To learn the molecular and cellular basis of tubulogenesis, we focus on the Drosophila trachea and salivary gland as model systems. Understanding how organ size, shape and function is normally controlled will provide key strategies for utilizing stems cells for the replacement of diseased and/or damaged organs.

My lab has identified many genes expressed in the trachea and salivary gland and are characterizing the subset required for early tube morphogenesis. Two of the genes encode transcription factors required for internalization of either the trachea or salivary gland, trachealess and fork head. Three genes encode transcription factors controlling tube elongation, ribbon, huckebein and hairy. Finally, several genes encode components of signaling pathways required for organ positioning. Current efforts in the lab are directed toward identifying and characterizing the downstream effector molecules regulated by these transcription factors and signaling pathways.

We also study the mechanisms whereby the salivary gland becomes specialized for secretion. We have shown that genes encoding components of the early secretory pathway are transcriptionally upregulated in the salivary gland from very early embryonic stage. Interestingly, expression of secretory pathway genes in the salivary gland and in other secretory tissues is largely controlled by a single transcription factor, CrebA.

Publications:

Abrams, E.W., Mihoulides, W.K. and Andrew, D.J. (2006) Fork head and Sage maintain a uniform and patent salivary gland lumen through regulation of two downstream target genes, PH4áSG1 and PH4áSG2. Development 133: 3517-3527.
PubMed Reference

Kerman, B. E. Cheshire, A.M., and Andrew, D.J. (2006) From fate to function: the Drosophila trachea and salivary gland as models for tubulogenesis. Differentiation 74: 326-348.
PubMed Reference

Abrams, E.W. and Andrew, D.J. (2005) CrebA regulates secretory activity in the Drosophila salivary gland and epidermis. Development 132: 2743-2758.
PubMed Reference

Myat, M.M. and Andrew, D.J. (2002) Epithelial tube morphology is determined by the polarized growth and delivery of apical membrane. Cell 111:879-891.
PubMed Reference

Bradley, P.L. and Andrew, D.J. (2001) ribbon encodes a BTB-containing transcription factor required for directed cell migration. Development 128: 3001-3015.
PubMed Reference