# CELL LINEAGE AND SEGMENTATION IN LEECH NERVOUS SYSTEM

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA BERKELEY · 1994 · $164,185

## Abstract

The long term goal of this project is to elucidate cellular and molecular
mechanisms of development. This is basic research that will contribute to
the understanding and eventual amelioration of genetic and environmentally
induced developmental disorders and to the training of future biomedical
health researchers. The rationale for the proposed research is as follows:

It is increasingly clear that, as with many metabolic and structural
proteins, many developmental regulatory proteins also show a high degree of
evolutionary conservation, so that homologs of these genes, identified
mainly by genetic techniques in Drosophila, can be identified in vertebrate
and other invertebrates. An important part of understanding how these genes
work is to understand how their embryonic expression and developmental
effects on individual cells are governed by interactions with other cells.
But in Drosophila and vertebrate embryos it is difficult to study
development at the level of single cells because of technical difficulties
such as the small size and large numbers of cells, difficulty in culturing
the embryos, and (in Drosophila) the fact that early development involves a
syncytial blastoderm stage, so that many early events occur in an
environment in which individual cells cannot be identified or examined.
Fortunately, we can carry out such cell-level studies of developmental
regulatory genes in leech with relative ease, because in leech embryos,
individually identified cells are accessible to experimental manipulations
both in the embryo and in the adult nervous system.

The specific aims of this project are as follows:

l) to continue characterizing the normal expression of the leech gene ht-en
(a homolog of the Drosophila segmentation gene engrailed; the question of
immediate interest is whether expression of engrailed-class genes is
associated with particular cell phenotypes in the embryo and/or in the
nervous system);

2) to look for cell fate changes after selective ablation of cells that
express ht-en;

3) to look for cell fate changes after specific mis-expression of ht-en;

4) to characterize the expression of leech homologs of other segmentation
genes, such as cubitus m.interruptus-Dominant and to test for the presence
of interactions among the cells expressing these genes and the cells
expressing ht-en.

## Key facts

- **NIH application ID:** 2198827
- **Project number:** 2R01HD023328-06A2
- **Recipient organization:** UNIVERSITY OF CALIFORNIA BERKELEY
- **SAM.gov UEI:** GS3YEVSS12N6
- **Principal Investigator:** DAVID A WEISBLAT
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1994
- **Award amount:** $164,185
- **Award type:** 2
- **Project period:** 1987-08-01 → 1997-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2198827

## Citation

> US National Institutes of Health, RePORTER application 2198827, CELL LINEAGE AND SEGMENTATION IN LEECH NERVOUS SYSTEM (2R01HD023328-06A2). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2198827. Licensed CC0.

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