# STEPS CONTROLLING GENE EXPRESSION

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA LOS ANGELES · 1994 · $220,579

## Abstract

A cell signalling pathway, encoded by the maternal terminal system and
bearing striking similarity to the PDGF-activated pathway in mammalian
systems, is active at both poles of the Drosophila embryo.  In the
posterior, this pathway is required to establish a largely unsegmented
domain, the telson.  In the anterior, a morphogen gradient, consisting of
the bicoid (bcd) transcription factor, interacts with the terminal system
to establish the nonsegmented acron instead of a telson.  The key zygotic
gene activated in each of these domains is tailless (tll), which encodes
a steroid receptor-like putative transcription factor.  To understand the
establishment of head at the anterior rather than tail, we will
characterize bcd control of tll in the anterior.  We will determine, using
both in vitro and in vivo techniques, bcd protein binding sites in the tll
promoter, and characterize their interaction with the terminal system.  To
understand how a nonsegmented domain is subdivided, we will investigate
the hierarchy of gene activity in the posterior. This will first involve
determination, in vitro and in vivo, of tll protein binding sites in
presumed target genes (both those activated and those repressed by tll).
Because so few genes are known that are required in the posterior, we will
carry out genetic screens to identify additional members of the terminal
hierarchy, and place described and newly discovered genes into a pathway.

Understanding in greater detail the gene expression activated by a cell
signalling pathway should contribute to our knowledge of genes that might
be deranged in oncogenesis.  Also, it is becoming evident that both
general mechanisms of developmental control, and even specific genes
required in embryogenesis, that have been identified in Drosophila have
homologs in vertebrates.  By characterizing a genetic hierarchy required
to subdivide an embryonic field into smaller, nonsegmented domains (as
occurs in the vertebrate dorsal-ventral axis, limb bud and retina) we will
increase our knowledge of mechanisms by which positional information is
interpreted and refined.  Ultimately this will allow us to understand the
genetic and cellular basis of human birth defects.

## Key facts

- **NIH application ID:** 2196695
- **Project number:** 5R01HD009948-18
- **Recipient organization:** UNIVERSITY OF CALIFORNIA LOS ANGELES
- **SAM.gov UEI:** RN64EPNH8JC6
- **Principal Investigator:** JUDITH A LENGYEL
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1994
- **Award amount:** $220,579
- **Award type:** 5
- **Project period:** 1976-09-30 → 1997-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2196695

## Citation

> US National Institutes of Health, RePORTER application 2196695, STEPS CONTROLLING GENE EXPRESSION (5R01HD009948-18). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2196695. Licensed CC0.

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