# EXPRESSION AND FUNCTION OF MAMMALIAN HOMEOBOX GENES

> **NIH NIH R01** · UNIVERSITY OF SOUTHERN CALIFORNIA · 1994 · $283,268

## Abstract

Valuable insight into normal and abnormal embryonic development may be
gained from the study of genes and gene products that control these
processes.  Current knowledge on the structure, evolution and expression of
mammalian homeobox genes identifies these as excellent candidates for loci
that regulate mammalian development.  We propose experiments that explore
the regulation of the homeobox genes Hox 1.3 and Hox 5.1 and the function
of Hox 1.3.

1.  The cis-acting elements responsible for the spatial expression of Hox
1.3/lacZ and Hox 5.1/lacZ gene fusions in the central nervous system of
transgenic mice will be defined.  The cis-acting elements will be used as
affinity tools in order to characterize the trans-acting factors involved.

2.  Previous results suggest that the developing spinal cord may be
subdivided into discrete rostrocaudal regions based on the activity of
particular Hox genes.  Therefore the brachial and cervical CNS cells from
Hox 1.3/lacZ and Hox 5.1/lacZ mice will be purified using a protocol based
on fluorescence activated cell sorting of lacZ+ cells.  It will then be
determined whether the brachial and cervical CNS domain express different
combinations of active genes, including Hox genes.  This analysis will be
done with purified cells using immunoblots, RNase mapping and subtractive
cDNA cloning.  Genetic ablation of brachial cells will also be performed in
transgenic mice expressing a Hox 1.3/diphtheria toxin A fusion gene.  The
resulting phenotype will be described.

3.  Transgenic mice that express ectopically the Hox 1.3 coding region
under the control of the ubiquitous GRP70 promoter or the specific Hox 5.1
promoter will be produced and analyzed with respect to several molecular
and morphological parameters.

4.  Vectors that allow for enrichment of ES cells containing a Hox 1.3 gene
activated by homologous recombination will be used to isolate such cells.
Chimeric mice will be produced from these ES cells and bred to generate
mice heterozygous and homozygous for the inactivated Hox 1.3 gene.

## Key facts

- **NIH application ID:** 2198526
- **Project number:** 5R01HD022416-07
- **Recipient organization:** UNIVERSITY OF SOUTHERN CALIFORNIA
- **SAM.gov UEI:** G88KLJR3KYT5
- **Principal Investigator:** Robert E. Maxson
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1994
- **Award amount:** $283,268
- **Award type:** 5
- **Project period:** 1989-02-01 → 1996-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2198526

## Citation

> US National Institutes of Health, RePORTER application 2198526, EXPRESSION AND FUNCTION OF MAMMALIAN HOMEOBOX GENES (5R01HD022416-07). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2198526. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*