[Federal Register Volume 65, Number 225 (Tuesday, November 21, 2000)]
[Notices]
[Pages 69949-69950]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-29716]
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DEPARTMENT OF HEALTH AND HUMAN SERVICES
National Institutes of Health
Government-Owned Inventions; Availability for Licensing
AGENCY: National Institutes of Health, Public Health Service, DHHS.
ACTION: Notice.
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SUMMARY: The inventions listed below are owned by agencies of the U.S.
Government and are available for licensing in the U.S. in accordance
with 35 U.S.C. 207 to achieve expeditious commercialization of results
of federally-funded research and development. Foreign patent
applications are filed on selected inventions to extend market coverage
for companies and may also be available for licensing.
ADDRESSES: Licensing information and copies of the U.S. patent
applications listed below may be obtained by writing to the indicated
licensing contact at the Office of Technology Transfer, National
Institutes of Health, 6011 Executive Boulevard, Suite 325, Rockville,
Maryland 20852-3804; telephone: 301/496-7057; fax: 301/402-0220. A
signed Confidential Disclosure Agreement will be required to receive
copies of the patent applications.
Enhanced Homologous Recombination Mediated by Lambda Recombination
Proteins
Donald L. Court, Daiguan Yu, E-Chaing Lee, Hilary Ellis, Nancy A.
Jenkins, Neal G. Copeland (NCI), DHHS Reference No. E-177-00/0 filed 14
Aug 2000, Licensing Contact: Dennis Penn; 301/496-7056 ext. 211; e-
mail: [email protected].
The present invention concerns methods to enhance homologous
recombination in bacteria and eukaryotic cells using recombination
proteins derived from bacteriophage lambda. It also concerns methods
for promoting homologous recombination using other recombination
proteins.
Concerted use of restriction endonucleases and DNA ligases allows
in vitro recombination of DNA sequences. The recombinant DNA generated
by restriction and ligation may be amplified in an appropriate
microorganism such as E. coli, and used for diverse purposes including
gene therapy. However, the restriction-ligation approach has two
practical limitations: first, DNA molecules can be precisely combined
only if convenient restriction sites are available; second, because
useful restriction sites often repeat in a long stretch of DNA, the
size of DNA fragments that can be manipulated are limited, usually to
less than about 20 kilobases.
Homologous recombination, generally defined as an exchange of
homologous segments anywhere along a length of two DNA molecules,
provides an alternative method for engineering DNA. In generating
recombinant DNA with homologous recombination, a microorganism such as
E. coli, or a eukaryotic cell such as a yeast or vertebrate cell, is
transformed with an exogenous strand of DNA. The center of the
exogenous DNA contains the desired transgene, whereas each flank
contains a segment of homology with the cell's DNA. The exogenous DNA
is introduced into the cell with standard techniques such as
electroporation or calcium phosphate-mediated transfection, and
recombines into the cell's DNA, for example with the assistance of
recombination-promoting proteins in the cell.
In generating recombinant DNA by homologous recombination, it is
often advantageous to work with short linear segments of DNA. For
example, a mutation may be introduced into a linear segment of DNA
using polymerase chain reaction (PCR) techniques. Under proper
circumstances, the mutation may then be introduced into cellular DNA by
homologous recombination. Such short linear DNA segments can transform
yeast, but subsequent manipulation of recombinant DNA in yeast is
laborious. It is generally easier to work in bacteria, but linear DNA
fragments do not readily transform bacteria (due in part to degradation
by bacterial exonucleases). Accordingly, recombinants are rare, require
special poorly-growing strains (such as RecBCD-strains) and generally
require thousands of base pairs of homology. This invention teaches an
improved method of promoting homologous recombination in bacteria.
In eukaryotic cells, targeted homologous recombination provides a
basis for targeting and altering essentially any desired sequence in a
duplex DNA molecule, such as targeting a DNA sequence in a chromosome
for replacement by another sequence. This invention teaches methods
useful for treating human genetic diseases, the creation of transgenic
animals, or modifying the germline of other organisms.
Amelogenin Knockout Mice and Use as Models for Tooth Disease
Dr. Ashok Kulkarni et al. (NIDCR), DHHS Reference No. E-167-00/0,
Licensing Contact: John Rambosek; 301/
[[Page 69950]]
496-7056 ext. 270; e-mail: [email protected].
This technology relates to transgenic knockout mice that may serve
as an animal model for dental disease. Using gene-targeting techniques,
mice have been created which are disrupted for the amelogenin gene.
These mice lack the amelogenin protein, which is normally expressed
only in the teeth. Since these mice lack this protein, they are
expected to mimic an inherited tooth disorder called ``amelogenesis
imperfecta (AI)''. AI is an inherited condition that is transmitted as
a dominant trait and causes the enamel of the tooth to be soft and thin
resulting in discoloration, disintegration and disfigurement of the
teeth. The damaged teeth are also susceptible to decay. The amelogenin
knockout mice display an interesting tooth phenotype. Their maxillary
incisors are chalky white in color and opaque in appearance.
These changes are associated with mild attrition of incisor tips
and molar cusps. Detailed analysis of this phenotype is in progress.
The amelogenin knockout mice may be used as an animal model to develop
therapeutic approaches to AI.
Transgenic Mouse Model for Tooth Disorders Such as Dentin Dysplasia
and Dentinogenesis Imperfecta
Drs. Thyagarajan, Sreenath, and Kulkarni (NIDCR), DHHS Reference
No. E-150-00/0, Licensing Contact: John Rambosek, Ph.D.; 301/496-7056;
e-mail: [email protected].
This technology describes transgenic mice that selectively
overexpress transforming growth factor beta-1 (TGF-beta1) in
odontoblast and ameloblast cells of teeth. Ameloblasts mainly make
enamel, whereas odontoblasts make dentin. These transgenic mice mimic
dental symptoms similar to those seen in common tooth disorders such as
dentin dysplasia and dentinogenesis imperfecta. Both of these human
dentin defects are inherited in an autosomal dominant manner and appear
to be caused by abnormal dentin production by odontoblasts and
associated poor mineralization of the dentin matrix. In both diseases,
teeth are discolored and fractured, causing difficulties in eating
food. Experimentally, these mice display discolored and fractured teeth
with defective dentin. This transgenic mice model will be valuable to
advance our understanding of the molecular pathogenesis underlying
dentin dysplasia and dentinogenesis imperfecta and also for developing
therapeutic strategies.
This material is available for licensing through a PHS Biological
Materials License.
Dated: November 13, 2000.
Jack Spiegel,
Director, Division of Technology Development and Transfer, Office of
Technology Transfer, National Institutes of Health.
[FR Doc. 00-29716 Filed 11-20-00; 8:45 am]
BILLING CODE 4140-01-P